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1.  Conflicts of Interest at Medical Journals: The Influence of Industry-Supported Randomised Trials on Journal Impact Factors and Revenue – Cohort Study 
PLoS Medicine  2010;7(10):e1000354.
Andreas Lundh and colleagues investigated the effect of publication of large industry-supported trials on citations and journal income, through reprint sales, in six general medical journals
Background
Transparency in reporting of conflict of interest is an increasingly important aspect of publication in medical journals. Publication of large industry-supported trials may generate many citations and journal income through reprint sales and thereby be a source of conflicts of interest for journals. We investigated industry-supported trials' influence on journal impact factors and revenue.
Methods and Findings
We sampled six major medical journals (Annals of Internal Medicine, Archives of Internal Medicine, BMJ, JAMA, The Lancet, and New England Journal of Medicine [NEJM]). For each journal, we identified randomised trials published in 1996–1997 and 2005–2006 using PubMed, and categorized the type of financial support. Using Web of Science, we investigated citations of industry-supported trials and the influence on journal impact factors over a ten-year period. We contacted journal editors and retrieved tax information on income from industry sources. The proportion of trials with sole industry support varied between journals, from 7% in BMJ to 32% in NEJM in 2005–2006. Industry-supported trials were more frequently cited than trials with other types of support, and omitting them from the impact factor calculation decreased journal impact factors. The decrease varied considerably between journals, with 1% for BMJ to 15% for NEJM in 2007. For the two journals disclosing data, income from the sales of reprints contributed to 3% and 41% of the total income for BMJ and The Lancet in 2005–2006.
Conclusions
Publication of industry-supported trials was associated with an increase in journal impact factors. Sales of reprints may provide a substantial income. We suggest that journals disclose financial information in the same way that they require them from their authors, so that readers can assess the potential effect of different types of papers on journals' revenue and impact.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Medical journals publish many different types of papers that inform doctors about the latest research advances and the latest treatments for their patients. They publish articles that describe laboratory-based research into the causes of diseases and the identification of potential new drugs. They publish the results of early clinical trials in which a few patients are given a potential new drug to check its safety. Finally and most importantly, they publish the results of randomized controlled trials (RCTs). RCTs are studies in which large numbers of patients are randomly allocated to different treatments without the patient or the clinician knowing the allocation and the efficacy of the various treatments compared. RCTs are best way of determining whether a new drug is effective and have to be completed before a drug can be marketed. Because RCTs are very expensive, they are often supported by drug companies. That is, drug companies provide grants or drugs for the trial or assist with data analysis and/or article preparation.
Why Was This Study Done?
Whenever a medical journal publishes an article, the article's authors have to declare any conflicts of interest such as financial gain from the paper's publication. Conflict of interest statements help readers assess papers—an author who owns the patent for a drug, for example, might put an unduly positive spin on his/her results. The experts who review papers for journals before publication provide similar conflict of interest statements. But what about the journal editors who ultimately decide which papers get published? The International Committee of Medical Journal Editors (ICMJE), which produces medical publishing guidelines, states that: “Editors who make final decisions about manuscripts must have no personal, professional, or financial involvement in any of the issues that they might judge.” However, the publication of industry-supported RCTs might create “indirect” conflicts of interest for journals by boosting the journal's impact factor (a measure of a journal's importance based on how often its articles are cited) and its income through the sale of reprints to drug companies. In this study, the researchers investigate whether the publication of industry-supported RCTs influences the impact factors and finances of six major medical journals.
What Did the Researchers Do and Find?
The researchers determined which RCTs published in the New England Journal of Medicine (NEJM), the British Medical Journal (BMJ), The Lancet, and three other major medical journals in 1996–1997 and 2005–2006 were supported wholly, partly, or not at all by industry. They then used the online academic citation index Web of Science to calculate an approximate impact factor for each journal for 1998 and 2007 and calculated the effect of the published RCTs on the impact factor. The proportion of RCTs with sole industry support varied between journals. Thus, 32% of the RCTs published in the NEJM during both two-year periods had industry support whereas only 7% of the RCTs published in the BMJ in 2005–2006 had industry support. Industry-supported trials were more frequently cited than RCTs with other types of support and omitting industry-supported RCTs from impact factor calculations decreased all the approximate journal impact factors. For example, omitting all RCTs with industry or mixed support decreased the 2007 BMJ and NEJM impact factors by 1% and 15%, respectively. Finally, the researchers asked each journal's editor about their journal's income from industry sources. For the BMJ and The Lancet, the only journals that provided this information, income from reprint sales was 3% and 41%, respectively, of total income in 2005–2006.
What Do These Findings Mean?
These findings show that the publication of industry-supported RCTs was associated with an increase in the approximate impact factors of these six major medical journals. Because these journals publish numerous RCTs, this result may not be generalizable to other journals. These findings also indicate that income from reprint sales can be a substantial proportion of a journal's total income. Importantly, these findings do not imply that the decisions of editors are affected by the possibility that the publication of an industry-supported trial might improve their journal's impact factor or income. Nevertheless, the researchers suggest, journals should live up to the same principles related to conflicts of interest as those that they require from their authors and should routinely disclose information on the source and amount of income that they receive.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000354.
This study is further discussed in a PLoS Medicine Perspective by Harvey Marcovitch
The International Committee of Medical Journal Editors provides information about the publication of medical research, including conflicts of interest
The World Association of Medical Editors also provides information on conflicts of interest in medical journals
Information about impact factors is provided by Thomson Reuters, a provider of intelligent information for businesses and professionals; Thomson Reuters also runs Web of Science
doi:10.1371/journal.pmed.1000354
PMCID: PMC2964336  PMID: 21048986
2.  Accelerated publication versus usual publication in 2 leading medical journals 
Background
A number of medical journals have developed policies for accelerated publication of articles judged by the authors, the editors or the peer reviewers to be of special importance. However, the validity of these judgements is unknown. We therefore compared the importance of articles published on a “fast track” with those published in the usual way.
Methods
We identified 12 “case” articles — 6 articles from the New England Journal of Medicine that were prereleased on the journal's Web site before publication in print and 6 “fast-tracked” articles from The Lancet. We then identified 12 “control” articles matched to the case articles according to journal, disease or procedure of focus, theme area and year of publication. Forty-two general internists rated the articles, using 10-point scales, on dimensions addressing the articles' importance, ease of applicability and impact on health outcomes.
Results
For each dimension, the mean score for the case articles was significantly higher than the mean score for the control articles: importance to clinical practice 7.6 v. 7.1 respectively (p = 0.001), importance from a public health perspective 6.5 v. 6.0 (p < 0.001), contribution to advancement of medical knowledge 6.2 v. 5.8 (p < 0.001), ease of applicability in practice 7.0 v. 6.5 (p < 0.001), potential impact on health outcomes 6.5 v. 5.9 (p < 0.001). Despite these general findings, in 5 of the 12 matched pairs of articles the control article had a higher mean score than the case article across all the dimensions.
Interpretation
The accelerated publication practices of 2 leading medical journals targeted articles that, on average, had slightly higher importance scores than similar articles published in the usual way. However, our finding of higher importance scores for control articles in 5 of the 12 matched pairs shows that current journal practices for selecting articles for expedited publication are inconsistent.
PMCID: PMC102352  PMID: 12000245
3.  International Monetary Fund Programs and Tuberculosis Outcomes in Post-Communist Countries 
PLoS Medicine  2008;5(7):e143.
Background
Previous studies have indicated that International Monetary Fund (IMF) economic programs have influenced health-care infrastructure in recipient countries. The post-communist Eastern European and former Soviet Union countries experienced relatively similar political and economic changes over the past two decades, and participated in IMF programs of varying size and duration. We empirically examine how IMF programs related to changes in tuberculosis incidence, prevalence, and mortality rates among these countries.
Methods and Findings
We performed multivariate regression of two decades of tuberculosis incidence, prevalence, and mortality data against variables potentially influencing tuberculosis program outcomes in 21 post-communist countries for which comparative data are available. After correcting for confounding variables, as well as potential detection, selection, and ecological biases, we observed that participating in an IMF program was associated with increased tuberculosis incidence, prevalence, and mortality rates by 13.9%, 13.2%, and 16.6%, respectively. Each additional year of participation in an IMF program was associated with increased tuberculosis mortality rates by 4.1%, and each 1% increase in IMF lending was associated with increased tuberculosis mortality rates by 0.9%. On the other hand, we estimated a decrease in tuberculosis mortality rates of 30.7% (95% confidence interval, 18.3% to 49.5%) associated with exiting the IMF programs. IMF lending did not appear to be a response to worsened health outcomes; rather, it appeared to be a precipitant of such outcomes (Granger- and Sims-causality tests), even after controlling for potential political, socioeconomic, demographic, and health-related confounders. In contrast, non-IMF lending programs were connected with decreased tuberculosis mortality rates (−7.6%, 95% confidence interval, −1.0% to −14.1%). The associations observed between tuberculosis mortality and IMF programs were similar to those observed when evaluating the impact of IMF programs on tuberculosis incidence and prevalence. While IMF programs were connected with large reductions in generalized government expenditures, tuberculosis program coverage, and the number of physicians per capita, non-IMF lending programs were not significantly associated with these variables.
Conclusions
IMF economic reform programs are associated with significantly worsened tuberculosis incidence, prevalence, and mortality rates in post-communist Eastern European and former Soviet countries, independent of other political, socioeconomic, demographic, and health changes in these countries. Future research should attempt to examine how IMF programs may have related to other non-tuberculosis–related health outcomes.
David Stuckler and colleagues show that, in Eastern European and former Soviet Union countries, participation in International Monetary Fund economic programs have been associated with higher mortality rates from tuberculosis.
Editors' Summary
Background.
Tuberculosis—a contagious, bacterial infection—has killed large numbers of people throughout human history. Over the last century improvements in public health began to reduce the incidence (the number of new cases in the population in a given time), prevalence (the number of infected people), and mortality rate (number of people dying each year) of tuberculosis in several countries. Many authorities thought that tuberculosis had become a disease of the past. It has become increasingly clear, however, that regions impacted by health and economic changes since the 1980s have continued to face a high and sometimes increasing burden of tuberculosis. In order to boost funding and resources for combating the global tuberculosis problem, the United Nations has set a target of halting and reversing increases in global tuberculosis incidence by 2015 as one of its Millennium Development Goals. Yet one region of the world—Eastern Europe and the former Soviet Union—is not on track to achieve this goal.
Why Was This Study Done?
To achieve these targets, the World Health Organization (WHO) and tuberculosis physicians' groups promote the expansion of detection and treatment efforts against tuberculosis. But these efforts depend on the maintenance of good health infrastructure to fund and support health-care workers, clinics, and hospitals. In countries with significant financial limitations, the development and maintenance of these health system resources are often dependent upon international donations and financial lending. The International Monetary Fund (IMF) is a major source of capital for resource-deprived countries, but it is unclear whether its economic reform programs have positive or negative effects on health and health infrastructures in recipient countries. There are indications, for example, that recipient countries sometimes reduce their public-health spending to meet the economic targets set by the IMF as conditions for its loans. In this study, the researchers examine the relationship between participating in IMF lending programs of varying sizes and durations by 21 post-communist Central and Eastern European and former Soviet Union countries and changes in tuberculosis incidence, prevalence, and mortality in these countries during the past two decades.
What Did the Researchers Do and Find?
To examine how participation in IMF lending programs affected tuberculosis control in these countries, the researchers developed a series of statistical models that take into account other variables (for example, directly observed therapy programs, HIV rates, military conflict, and urbanization) that might have affected tuberculosis control. Participation in an IMF program, they report, was associated with increases in tuberculosis incidence, prevalence, and mortality rate of about 15%, which corresponds to hundreds of thousands of new cases and deaths in this region. Each additional year of participation increased tuberculosis mortality rates by 4.1%; increases in the size of the IMF loan also corresponded to greater tuberculosis mortality rates. Conversely, when countries left IMF programs, tuberculosis mortality rates dropped by roughly one-third. The authors' further statistical tests indicated that IMF lending was not a positive response to worsened tuberculosis control but precipitated this adverse outcome and that lending from non-IMF sources of funding was associated with decreases in tuberculosis mortality rates. Consistent with these results, IMF (but not non-IMF) programs were associated with reductions in government expenditures, tuberculosis program coverage, and the number of doctors per capita in each country. These findings associated with mortality were also found when analyzing tuberculosis incidence and prevalence data.
What Do These Findings Mean?
These findings indicate that IMF economic programs are associated with significantly worsened tuberculosis control in post-communist Central and Eastern European and former Soviet Union countries, independent of other political, health, and economic changes in these countries. Further research is needed to discover exactly which aspects of the IMF programs were associated with the adverse effects on tuberculosis control reported here and to see whether IMF loans have similar effects on tuberculosis control in other countries or on other non–tuberculosis-related health outcomes. For now, these results challenge the proposition that the forms of economic development promoted by the IMF necessarily improve public health. In particular, they put the onus on the IMF to critically evaluate the direct and indirect effects of its economic programs on public health.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050143.
This study is further discussed in a PLoS Medicine Perspective by Murray and King
The US National Institute of Allergy and Infectious Diseases provides information on all aspects of tuberculosis, including a brief history of the disease
The US Centers for Disease Control and Prevention provide several fact sheets and other information resources about tuberculosis
The World Health Organization provides information (in several languages) on efforts to reduce the global burden of tuberculosis, including information on the Stop TB Strategy and the 2008 report on global tuberculosis control—surveillance, planning, financing
Detailed information about the International Monetary Fund is available on its Web site
An article that asks “Does the IMF constrain health spending in poor countries?” (with a link to a response from the IMF) is provided by the Center for Global Development
doi:10.1371/journal.pmed.0050143
PMCID: PMC2488179  PMID: 18651786
4.  Timing and Completeness of Trial Results Posted at ClinicalTrials.gov and Published in Journals 
PLoS Medicine  2013;10(12):e1001566.
Agnes Dechartres and colleagues searched ClinicalTrials.gov for completed drug RCTs with results reported and then searched for corresponding studies in PubMed to evaluate timeliness and completeness of reporting.
Please see later in the article for the Editors' Summary
Background
The US Food and Drug Administration Amendments Act requires results from clinical trials of Food and Drug Administration–approved drugs to be posted at ClinicalTrials.gov within 1 y after trial completion. We compared the timing and completeness of results of drug trials posted at ClinicalTrials.gov and published in journals.
Methods and Findings
We searched ClinicalTrials.gov on March 27, 2012, for randomized controlled trials of drugs with posted results. For a random sample of these trials, we searched PubMed for corresponding publications. Data were extracted independently from ClinicalTrials.gov and from the published articles for trials with results both posted and published. We assessed the time to first public posting or publishing of results and compared the completeness of results posted at ClinicalTrials.gov versus published in journal articles. Completeness was defined as the reporting of all key elements, according to three experts, for the flow of participants, efficacy results, adverse events, and serious adverse events (e.g., for adverse events, reporting of the number of adverse events per arm, without restriction to statistically significant differences between arms for all randomized patients or for those who received at least one treatment dose).
From the 600 trials with results posted at ClinicalTrials.gov, we randomly sampled 50% (n = 297) had no corresponding published article. For trials with both posted and published results (n = 202), the median time between primary completion date and first results publicly posted was 19 mo (first quartile = 14, third quartile = 30 mo), and the median time between primary completion date and journal publication was 21 mo (first quartile = 14, third quartile = 28 mo). Reporting was significantly more complete at ClinicalTrials.gov than in the published article for the flow of participants (64% versus 48% of trials, p<0.001), efficacy results (79% versus 69%, p = 0.02), adverse events (73% versus 45%, p<0.001), and serious adverse events (99% versus 63%, p<0.001).
The main study limitation was that we considered only the publication describing the results for the primary outcomes.
Conclusions
Our results highlight the need to search ClinicalTrials.gov for both unpublished and published trials. Trial results, especially serious adverse events, are more completely reported at ClinicalTrials.gov than in the published article.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
When patients consult a doctor, they expect to be recommended what their doctor believes is the most effective treatment with the fewest adverse effects. To determine which treatment to recommend, clinicians rely on sources that include research studies. Among studies, the best evidence is generally agreed to come from systematic reviews and randomized controlled clinical trials (RCTs), studies that test the efficacy and safety of medical interventions by comparing clinical outcomes in groups of patients randomly chosen to receive different interventions. Decision-making based on the best available evidence is called evidence-based medicine. However, evidence-based medicine can only guide clinicians if trial results are published in a timely and complete manner. Unfortunately, underreporting of trials is common. For example, an RCT in which a new drug performs better than existing drugs is more likely to be published than one in which the new drug performs badly or has unwanted adverse effects (publication bias). There can also be a delay in publishing the results of negative trials (time-lag bias) or a failure to publish complete results for all the prespecified outcomes of a trial (reporting bias). All three types of bias threaten informed medical decision-making and the health of patients.
Why Was This Study Done?
One initiative that aims to prevent these biases was included in the 2007 US Food and Drug Administration Amendments Act (FDAAA). The Food and Drug Administration (FDA) is responsible for approving drugs and devices that are marketed in the US. The FDAAA requires that results from clinical trials of FDA-approved drugs and devices conducted in the United States be made publicly available at ClinicalTrials.gov within one year of trial completion. ClinicalTrials.gov—a web-based registry that includes US and international clinical trials—was established in 2000 in response to the 1997 FDA Modernization Act, which required mandatory registration of trial titles and designs and of the conditions and interventions under study. The FDAAA expanded these mandatory requirements by requiring researchers studying FDA-approved drugs and devices to report additional information such as the baseline characteristics of the participants in each arm of the trial and the results of primary and secondary outcome measures (the effects of the intervention on predefined clinical measurements) and their statistical significance (an indication of whether differences in outcomes might have happened by chance). Researchers of other trials registered in ClinicalTrials.gov are welcome to post trial results as well. Here, the researchers compare the timing and completeness (i.e., whether all relevant information was fully reported) of results of drug trials posted at ClinicalTrials.gov with those published in medical journals.
What Did the Researchers Do and Find?
The researchers searched ClinicalTrials.gov for reports of completed phase III and IV (late-stage) RCTs of drugs with posted results. For a random sample of 600 eligible trials, they searched PubMed (a database of biomedical publications) for corresponding publications. Only 50% of trials with results posted at ClinicalTrials.gov had a matching published article. For 202 trials with both posted and published results, the researchers compared the timing and completeness of the results posted at ClinicalTrials.gov and of results reported in the corresponding journal publication. The median time between the study completion date and the first results being publicly posted at ClinicalTrials.gov was 19 months, whereas the time between completion and publication in a journal was 21 months. The flow of participants through trials was completely reported in 64% of the ClinicalTrials.gov postings but in only 48% of the corresponding publications. Results for the primary outcome measure were completely reported in 79% and 69% of the ClinicalTrials.gov postings and corresponding publications, respectively. Finally, adverse events were completely reported in 73% of the ClinicalTrials.gov postings but in only 45% of the corresponding publications, and serious adverse events were reported in 99% and 63% of the ClinicalTrials.gov postings and corresponding publications, respectively.
What Do These Findings Mean?
These findings suggest that the reporting of trial results is significantly more complete at ClinicalTrials.gov than in published journal articles reporting the main trial results. Certain aspects of this study may affect the accuracy of this conclusion. For example, the researchers compared the results posted at ClinicalTrials.gov only with the results in the publication that described the primary outcome of each trial, even though some trials had multiple publications. Importantly, these findings suggest that, to enable patients and physicians to make informed treatment decisions, experts undertaking assessments of drugs should consider seeking efficacy and safety data posted at ClinicalTrials.gov, both for trials whose results are not published yet and for trials whose results are published. Moreover, they suggest that the use of templates to guide standardized reporting of trial results in journals and broader mandatory posting of results may help to improve the reporting and transparency of clinical trials and, consequently, the evidence available to inform treatment of patients.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001566.
Wikipedia has pages on evidence-based medicine and on publication bias (note: Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The US Food and Drug Administration provides information about drug approval in the US for consumers and health-care professionals, plus detailed information on the 2007 Food and Drug Administration Amendments Act
ClinicalTrials.gov provides information about the US National Institutes of Health clinical trial registry, including background information about clinical trials, and a fact sheet detailing the requirements of the 2007 Food and Drug Administration Amendments Act
PLOS Medicine recently launched a Reporting Guidelines Collection, an open access collection of reporting guidelines, commentary, and related research on guidelines from across PLOS journals that aims to help advance the efficiency, effectiveness, and equitability of the dissemination of biomedical information; a 2008 PLOS Medicine editorial discusses the 2007 Food and Drug Administration Amendments Act
doi:10.1371/journal.pmed.1001566
PMCID: PMC3849189  PMID: 24311990
5.  Relation between randomized controlled trials published in leading general medical journals and the global burden of disease 
Background
More than two-thirds of the world's population live in low-income countries, where health priorities are different from those of people living in more affluent parts of the world. We evaluated the relation between the global burden of disease and conditions or diseases studied in randomized controlled trials (RCTs) published in general medical journals.
Methods
A MEDLINE search identified 373 RCTs that had been published in 6 international peer-reviewed general medical journals in 1999. Manual review excluded non-RCTs, brief reports and trials in which the unit of randomization was not the patient; 286 RCTs remained eligible for analysis. We identified the RCTs that studied any of the 40 leading causes of the global burden of disease. Five of these conditions were considered unsuitable for study with an RCT design and were excluded from subsequent analysis. To provide a practical perspective, we asked 12 experts working with international health organizations to rate the relevance to global health of the articles that studied any of the top 10 causes of the global burden of disease, as measured by disability-adjusted life years (DALYs) and mortality, using a 5-point Likert scale.
Results
Among the 286 RCTs in our sample, 124 (43.4%) addressed 1 of the 35 leading causes of the global burden of disease. Of these, ischemic heart disease, HIV/AIDS and cerebrovascular disease were the most commonly studied conditions. Ninety articles (31.5%) studied 1 of the top 10 causes of the global burden of disease. The mean rating (and standard deviation) for international health relevance assigned by experts was 2.6 (1.5) out of 5. Only 14 (16%) of the 90 trials received a rating of 4 or greater, indicating high relevance to international health. Almost half of the 40 leading causes of the global burden of disease were not studied by any trial.
Interpretation
Many conditions or diseases common internationally are underrepresented in RCTs published in leading general medical journals. Trials published in these journals that studied one of these high-priority conditions were generally rated as being of little relevance to international health.
doi:10.1503/cmaj.1031006
PMCID: PMC408507  PMID: 15159365
6.  The developing world in The New England Journal of Medicine 
Background
Rampant disease in poor countries impedes development and contributes to growing North-South disparities; however, leading international medical journals underreport on health research priorities for developing countries.
Methods
We examined 416 weekly issues of the New England Journal of Medicine (NEJM) over an eight-year period, January 1997 to December 2004. A total of 8857 articles were reviewed by both authors. The content of each issue was evaluated in six categories: research, review articles, editorial, correspondence, book reviews and miscellaneous. If the title or abstract concerned a topic pertinent to any health issue in the developing world, the article was reviewed.
Results
Over the eight years covered in this study, 1997–2004, in the three essential categories of original research articles, review articles and editorials, less than 3.0 percent of these addressed health issues in the developing world. Publications relevant to DC were largely concerned with HIV and communicable diseases and constituted 135 of the 202 articles of which 63 were devoted to HIV. Only 23 articles addressed non-communicable disease in the DC and only a single article – a book review – discussed heart disease.
Conclusion
The medical information gap between rich and poor countries as judged by publications in the NEJM appears to be larger than the gap in the funding for research. Under-representation of developing world health issues in the medical literature is a global phenomenon. International medical journals cannot rectify global inequities, but they have an important role in educating their constituencies about the global divide.
doi:10.1186/1744-8603-2-3
PMCID: PMC1459140  PMID: 16542448
7.  Relation between the Global Burden of Disease and Randomized Clinical Trials Conducted in Latin America Published in the Five Leading Medical Journals 
PLoS ONE  2008;3(2):e1696.
Background
Since 1990 non communicable diseases and injuries account for the majority of death and disability-adjusted life years in Latin America. We analyzed the relationship between the global burden of disease and Randomized Clinical Trials (RCTs) conducted in Latin America that were published in the five leading medical journals.
Methodology/Principal Findings
We included all RCTs in humans, exclusively conducted in Latin American countries, and published in any of the following journals: Annals of Internal Medicine, British Medical Journal, Journal of the American Medical Association, Lancet, and New England Journal of Medicine. We described the trials and reported the number of RCTs according to the main categories of the global burden of disease. Sixty-six RCTs were identified. Communicable diseases accounted for 38 (57%) reports. Maternal, perinatal, and nutritional conditions accounted for 19 (29%) trials. Non-communicable diseases represent 48% of the global burden of disease but only 14% of reported trials. No trial addressed injuries despite its 18% contribution to the burden of disease in 2000.
Conclusions/Significance
A poor correlation between the burden of disease and RCTs publications was found. Non communicable diseases and injuries account for up to two thirds of the burden of disease in Latin America but these topics are seldom addressed in published RCTs in the selected sample of journals. Funding bodies of health research and editors should be aware of the increasing burden of non communicable diseases and injuries occurring in Latin America to ensure that this growing epidemic is not neglected in the research agenda and not affected by publication bias.
doi:10.1371/journal.pone.0001696
PMCID: PMC2246037  PMID: 18301772
8.  Medline-based bibliometric analysis of gastroenterology journals between 2001 and 2007 
AIM: To analyze the MEDLINE-indexed publications in gastroenterology specialty journals from 2001 to 2007. Special attention was paid to specific types of articles, the number of publications for individual authors and the author count in each journal.
METHODS: The bibliographic entries of papers belonging to journals listed under the subject heading of “gastroenterology” were downloaded from MEDLINE on the PubMed web site. The analysis was limited to journal articles published between January 1, 2001 and December 31, 2007. The analytical dimensions of an article included journal, publication year, publication type, and author name (the last name and initials).
RESULTS: According to MEDLINE, 81 561 articles were published in 91 gastroenterology journals from 2001 to 2007. The number of articles increased from 9447 in 2001 to 13 340 in 2007. Only 12 journals had more than 2000 articles indexed in MEDLINE. The “World Journal of Gastroenterology” had the largest number of publications (5684 articles), followed by “Hepato-Gastroenterology” (3036) and “Gastrointestinal Endoscopy” (3005). Of all the articles published, reviews accounted for 17.2% and case reports for 15.4%. Only 3739 randomized controlled trials (4.6% of all articles) were published and their annual number increased from 442 in 2001 to 572 in 2007. Among 141 741 author names appearing in the articles of gastroenterology journals, 92 429 had published only in one journal, 22 585 in two journals, 9996 in three journals, and 16 731 in more than three journals. The “World Journal of Gastroenterology” had the greatest number of authors (17 838), followed by “Gastroenterology” (12 770), “Digestive Diseases and Sciences” (11 395), “American Journal of Gastroenterology” (10 889), and “Hepatology” (10 588).
CONCLUSION: Global gastroenterology publications displayed a continuous growth in the new millennium. The change was most striking in certain journals. Regular bibliometric analyses on the trends and specific topics would help researchers publish more efficiently and allow editors to adjust the policy more accurately.
doi:10.3748/wjg.15.2933
PMCID: PMC2699018  PMID: 19533822
Bibliographic databases; Bibliometrics; Biomedical research; Gastroenterology; MEDLINE
9.  Estimating the Global Clinical Burden of Plasmodium falciparum Malaria in 2007 
PLoS Medicine  2010;7(6):e1000290.
Simon Hay and colleagues derive contemporary estimates of the global clinical burden of Plasmodium falciparum malaria (the deadliest form of malaria) using cartography-based techniques.
Background
The epidemiology of malaria makes surveillance-based methods of estimating its disease burden problematic. Cartographic approaches have provided alternative malaria burden estimates, but there remains widespread misunderstanding about their derivation and fidelity. The aims of this study are to present a new cartographic technique and its application for deriving global clinical burden estimates of Plasmodium falciparum malaria for 2007, and to compare these estimates and their likely precision with those derived under existing surveillance-based approaches.
Methods and Findings
In seven of the 87 countries endemic for P. falciparum malaria, the health reporting infrastructure was deemed sufficiently rigorous for case reports to be used verbatim. In the remaining countries, the mapped extent of unstable and stable P. falciparum malaria transmission was first determined. Estimates of the plausible incidence range of clinical cases were then calculated within the spatial limits of unstable transmission. A modelled relationship between clinical incidence and prevalence was used, together with new maps of P. falciparum malaria endemicity, to estimate incidence in areas of stable transmission, and geostatistical joint simulation was used to quantify uncertainty in these estimates at national, regional, and global scales.
Combining these estimates for all areas of transmission risk resulted in 451 million (95% credible interval 349–552 million) clinical cases of P. falciparum malaria in 2007. Almost all of this burden of morbidity occurred in areas of stable transmission. More than half of all estimated P. falciparum clinical cases and associated uncertainty occurred in India, Nigeria, the Democratic Republic of the Congo (DRC), and Myanmar (Burma), where 1.405 billion people are at risk.
Recent surveillance-based methods of burden estimation were then reviewed and discrepancies in national estimates explored. When these cartographically derived national estimates were ranked according to their relative uncertainty and replaced by surveillance-based estimates in the least certain half, 98% of the global clinical burden continued to be estimated by cartographic techniques.
Conclusions and Significance
Cartographic approaches to burden estimation provide a globally consistent measure of malaria morbidity of known fidelity, and they represent the only plausible method in those malaria-endemic countries with nonfunctional national surveillance. Unacceptable uncertainty in the clinical burden of malaria in only four countries confounds our ability to evaluate needs and monitor progress toward international targets for malaria control at the global scale. National prevalence surveys in each nation would reduce this uncertainty profoundly. Opportunities for further reducing uncertainty in clinical burden estimates by hybridizing alternative burden estimation procedures are also evaluated.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Malaria is a major global public-health problem. Nearly half the world's population is at risk of malaria, and Plasmodium falciparum malaria—the deadliest form of the disease—causes about one million deaths each year. Malaria is a parasitic disease that is transmitted to people through the bite of an infected mosquito. These insects inject a parasitic form known as sporozoites into people, where they replicate briefly inside liver cells. The liver cells then release merozoites (another parasitic form), which invade red blood cells. Here, the merozoites replicate rapidly before bursting out and infecting more red blood cells. This increase in the parasitic burden causes malaria's characteristic symptoms—debilitating and recurring fevers and chills. Infected red blood cells also release gametocytes, which infect mosquitoes when they take a blood meal. In the mosquito, the gametocytes multiply and develop into sporozoites, thus completing the parasite's life cycle. Malaria can be prevented by controlling the mosquitoes that spread the parasite and by avoiding mosquito bites. Effective treatment with antimalarial drugs also helps to reduce malaria transmission.
Why Was This Study Done?
In 1998, the World Health Organization (WHO) and several other international agencies launched Roll Back Malaria, a global partnership that aims to provide a coordinated, global approach to fighting malaria. For this or any other malaria control initiative to be effective, however, an accurate picture of the global clinical burden of malaria (how many people become ill because of malaria and where they live) is needed so that resources can be concentrated where they will have the most impact. Estimates of the global burden of many infectious diseases are obtained using data collected by national surveillance systems. Unfortunately, this approach does not work very well for malaria because in places where malaria is endemic (always present), diagnosis is often inaccurate and national reporting is incomplete. In this study, therefore, the researchers use an alternative, “cartographic” method for estimating the global clinical burden of P. falciparum malaria.
What Did the Researchers Do and Find?
The researchers identified seven P. falciparum malaria-endemic countries that had sufficiently reliable health information systems to determine the national clinical malaria burden in 2007 directly. They divided the other 80 malaria endemic countries into countries with a low risk of transmission (unstable transmission) and countries with a moderate or high risk of transmission (stable transmission). In countries with unstable transmission, the researchers assumed a uniform annual clinical incidence rate of 0.1 cases per 1,000 people and multiplied this by population sizes to get disease burden estimates. In countries with stable transmission, they used a modeled relationship between clinical incidence (number of new cases in a population per year) and prevalence (the proportion of a population infected with malaria parasites) and a global malaria endemicity map (a map that indicates the risk of malaria infection in different countries) to estimate malaria incidences. Finally, they used a technique called “joint simulation” to quantify the uncertainty in these estimates. Together, these disease burden estimates gave an estimated global burden of 451 million clinical cases of P. falciparum in 2007. Most of these cases occurred in areas of stable transmission and more than half occurred in India, Nigeria, the Democratic Republic of the Congo, and Myanmar. Importantly, these four nations alone contributed nearly half of the uncertainty in the global incidence estimates.
What Do These Findings Mean?
These findings are extremely valuable because they provide a global map of malaria cases that should facilitate the implementation and evaluation of malaria control programs. However, the estimate of the global clinical burden of P. falciparum malaria reported here is higher than the WHO estimate of 247 million cases each year that was obtained using surveillance-based methods. The discrepancy between the estimates obtained using the cartographic and the surveillance-based approach is particularly marked for India. The researchers discuss possible reasons for these discrepancies and suggest improvements that could be made to both methods to increase the validity and precision of estimates. Finally, they note that improvements in the national prevalence surveys in India, Nigeria, the Democratic Republic of the Congo, and Myanmar would greatly reduce the uncertainty associated with their estimate of the global clinical burden of malaria, an observation that should encourage efforts to improve malaria surveillance in these countries.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000261.
A PLoS Medicine Health in Action article by Hay and colleagues, a Research Article by Guerra and colleagues, and a Research Article by Hay and colleagues provide further details about the global mapping of malaria risk
Additional national and regional level maps and more information on the global mapping of malaria are available at the Malaria Atlas Project
Information is available from the World Health Organization on malaria (in several languages)
The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish)
Information is available from the Roll Back Malaria Partnership on its approach to the global control of malaria (in English and French)
MedlinePlus provides links to additional information on malaria (in English and Spanish)
doi:10.1371/journal.pmed.1000290
PMCID: PMC2885984  PMID: 20563310
10.  Modelling the Impact of Artemisinin Combination Therapy and Long-Acting Treatments on Malaria Transmission Intensity 
PLoS Medicine  2008;5(11):e226.
Background
Artemisinin derivatives used in recently introduced combination therapies (ACTs) for Plasmodium falciparum malaria significantly lower patient infectiousness and have the potential to reduce population-level transmission of the parasite. With the increased interest in malaria elimination, understanding the impact on transmission of ACT and other antimalarial drugs with different pharmacodynamics becomes a key issue. This study estimates the reduction in transmission that may be achieved by introducing different types of treatment for symptomatic P. falciparum malaria in endemic areas.
Methods and Findings
We developed a mathematical model to predict the potential impact on transmission outcomes of introducing ACT as first-line treatment for uncomplicated malaria in six areas of varying transmission intensity in Tanzania. We also estimated the impact that could be achieved by antimalarials with different efficacy, prophylactic time, and gametocytocidal effects. Rates of treatment, asymptomatic infection, and symptomatic infection in the six study areas were estimated using the model together with data from a cross-sectional survey of 5,667 individuals conducted prior to policy change from sulfadoxine-pyrimethamine to ACT. The effects of ACT and other drug types on gametocytaemia and infectiousness to mosquitoes were independently estimated from clinical trial data. Predicted percentage reductions in prevalence of infection and incidence of clinical episodes achieved by ACT were highest in the areas with low initial transmission. A 53% reduction in prevalence of infection was seen if 100% of current treatment was switched to ACT in the area where baseline slide-prevalence of parasitaemia was lowest (3.7%), compared to an 11% reduction in the highest-transmission setting (baseline slide prevalence = 57.1%). Estimated percentage reductions in incidence of clinical episodes were similar. The absolute size of the public health impact, however, was greater in the highest-transmission area, with 54 clinical episodes per 100 persons per year averted compared to five per 100 persons per year in the lowest-transmission area. High coverage was important. Reducing presumptive treatment through improved diagnosis substantially reduced the number of treatment courses required per clinical episode averted in the lower-transmission settings although there was some loss of overall impact on transmission. An efficacious antimalarial regimen with no specific gametocytocidal properties but a long prophylactic time was estimated to be more effective at reducing transmission than a short-acting ACT in the highest-transmission setting.
Conclusions
Our results suggest that ACTs have the potential for transmission reductions approaching those achieved by insecticide-treated nets in lower-transmission settings. ACT partner drugs and nonartemisinin regimens with longer prophylactic times could result in a larger impact in higher-transmission settings, although their long term benefit must be evaluated in relation to the risk of development of parasite resistance.
Lucy Okell and colleagues predict the impact on transmission outcomes of ACT as first-line treatment for uncomplicated malaria in six areas of varying transmission intensity in Tanzania.
Editors' Summary
Background.
Plasmodium falciparum, a mosquito-borne parasite that causes malaria, kills nearly one million people every year. When an infected mosquito bites a person, it injects a life stage of the parasite called sporozoites, which invade human liver cells where they initially develop. The liver cells then release merozoites (another life stage of the parasite). These invade red blood cells where they multiply before bursting out and infecting more red blood cells, which can cause fever and damage vital organs. Some merozoites develop into gametocytes, which infect mosquitos when they take a blood meal. In the mosquito, the gametocytes give rise to sporozoites, thus completing the parasite's life cycle. Because malaria parasites are now resistant to many antimalarial drugs, the preferred first-line treatment for P. falciparum malaria in most countries is artemisinin combination therapy (ACT). Artemisinin derivatives are fast-acting antimalarial agents that, unlike previous first-line treatments, reduce the number of gametocytes in patients' blood, making them less infectious to mosquitos, and therefore have more potential to reduce malaria transmission. These compounds are used in combination with another antimalarial drug to reduce the chances of P. falciparum becoming resistant to either drug.
Why Was This Study Done?
Because malaria poses such a large global public-health burden, there is considerable national and international interest in eliminating it or at least minimizing its transmission. Malaria control agencies need to know how to choose between available types of ACT as well as other antimalarials so as to not only cure malaria illness but also prevent transmission as much as possible. The financial resources available to control malaria are limited, so for planning integrated transmission reduction programs it is important for policy makers to know what contribution their treatment policy could make in addition to other control strategies (for example, the provision of insecticide-treated bed nets to reduce mosquito bites) to reducing transmission. Furthermore, in areas with high levels of malaria, it is uncertain to what extent treatment can reduce transmission since many infected people are immune and do not suffer symptoms or seek health care, but continue to transmit to others. In this study, the researchers develop a mathematical model to predict the impact on malaria transmission of the introduction of ACT and alternative first-line treatments for malaria in six regions of Tanzania with different levels of malaria transmission.
What Did the Researchers Do and Find?
The researchers developed a “deterministic compartmental” model of malaria transmission in human and mosquito populations and included numerous variables likely to affect malaria transmission (variables were based on data collected in Tanzania just before the introduction of ACT). They then used the model to estimate the impact on malaria transmission of introducing ACT or other antimalarial drugs with different properties. The model predicted that the percentage reduction in the prevalence of infection (the fraction of the population with malaria) and the incidence of infection (the number of new cases in the population per year) associated with a 100% switch to ACT would be greater in areas with low initial transmission rates than in areas with high transmission rates. For example, in the area with the lowest initial transmission rates, the model predicted that the prevalence of infection would drop by 53%, but in the area with the highest initial transmission rate, the drop would be only 11%. However, because more people get malaria in high-transmission areas, the total number of malaria illness episodes prevented would be ten times higher in the area with highest transmission than in the area with lowest transmission. The model also predicted that, in areas with high transmission, long-acting treatments which protect patients from reinfection would reduce transmission more effectively than some common currently used ACT regimens which are gametocyte-killing but short-acting. Treatments which were both long-acting and gametocyte-killing were predicted to have the biggest impact across all settings.
What Do These Findings Mean?
As with all mathematical models, the accuracy of the predictions made by this model depend on the many assumptions incorporated into the model. In addition, because data from Tanzania were fed into the model, its predictions are to some extent specific to the area. Nevertheless the Tanzanian setting is typical of sub-Saharan malaria-affected areas, and the authors show that varying their assumptions and the data fed into the model within realistic ranges in most cases does not substantially change their overall conclusions. The findings in this study suggest that in low-transmission areas, provided ACT is widely used, ACT may reduce malaria transmission as effectively as the widespread use of insecticide-treated bed nets. The findings also suggest that the use of longer-acting regimens with or without artemisinin components might be a good way to reduce transmission in high-transmission areas, provided the development of parasite resistance can be avoided. More generally, these findings suggest that public-health officials need to take the properties of antimalarial drugs into account together with the levels of transmission in the area when designing policies in order to achieve the highest impact on malaria transmission.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050226.
This study is further discussed in a PLoS Medicine Perspective by Maciej Boni and colleagues
The MedlinePlus encyclopedia contains a page on malaria (in English and Spanish)
Information is available from the World Health Organization on malaria (in several languages)
The US Centers for Disease Control and Prevention provides information on malaria (in English and Spanish)
Information is available from the Roll Back Malaria Partnership on its approach to the global control of malaria, on artemisinin-based combination therapies, and on malaria in Tanzania
doi:10.1371/journal.pmed.0050226
PMCID: PMC2586356  PMID: 19067479
11.  Costs and Consequences of the US Centers for Disease Control and Prevention's Recommendations for Opt-Out HIV Testing 
PLoS Medicine  2007;4(6):e194.
Background
The United States Centers for Disease Control and Prevention (CDC) recently recommended opt-out HIV testing (testing without the need for risk assessment and counseling) in all health care encounters in the US for persons 13–64 years old. However, the overall costs and consequences of these recommendations have not been estimated before. In this paper, I estimate the costs and public health impact of opt-out HIV testing relative to testing accompanied by client-centered counseling, and relative to a more targeted counseling and testing strategy.
Methods and Findings
Basic methods of scenario and cost-effectiveness analysis were used, from a payer's perspective over a one-year time horizon. I found that for the same programmatic cost of US$864,207,288, targeted counseling and testing services (at a 1% HIV seropositivity rate) would be preferred to opt-out testing: targeted services would newly diagnose more HIV infections (188,170 versus 56,940), prevent more HIV infections (14,553 versus 3,644), and do so at a lower gross cost per infection averted (US$59,383 versus US$237,149). While the study is limited by uncertainty in some input parameter values, the findings were robust across a variety of assumptions about these parameter values (including the estimated HIV seropositivity rate in the targeted counseling and testing scenario).
Conclusions
While opt-out testing may be able to newly diagnose over 56,000 persons living with HIV in one year, abandoning client-centered counseling has real public health consequences in terms of HIV infections that could have been averted. Further, my analyses indicate that even when HIV seropositivity rates are as low as 0.3%, targeted counseling and testing performs better than opt-out testing on several key outcome variables. These analytic findings should be kept in mind as HIV counseling and testing policies are debated in the US.
Scenario and cost-effectiveness analyses found that for the same programmatic cost, targeted counseling and testing would diagnose more people living with HIV and prevent more HIV infections than opt-out testing.
Editors' Summary
Background.
About a quarter of a million people in the United States do not realize they are infected with HIV. Because they are unaware of their infection, they don't get the medicines they need to stay healthy, and they may also be transmitting HIV, the virus that causes AIDS, to others unwittingly. How can public health professionals best reach such people to offer them an HIV test? There are a number of different schools of thought, the two most common of which are studied in this paper.
The first is that the best way to reach them is by simply offering every single patient in every health care setting an HIV test, but giving them the option to decline. This approach is known as “opt-out testing” (because everyone gets tested unless they choose to opt out); it has recently been recommended by the leading US government agency responsible for promoting the US public's health, an agency called the Centers for Disease Control and Prevention (CDC). The CDC says that there is no need for patients to give specific written permission for the HIV test to be done and that there is no need for health professionals to offer counseling of what the consequences of a positive test might mean for them before the test.
The second school of thought is that public health professionals should instead target their efforts towards those who are at increased risk of being HIV positive, such as those who inject drugs or who have had high-risk sex. Persons at risk of infection or transmission are offered counseling before the test, to assess their actual risk of HIV and to discuss what would happen in the event that the HIV test comes back positive. During counseling, people are also given advice on steps they can take to stay HIV negative if their test comes back negative, and to prevent infecting others if their test comes back positive. This approach to HIV testing is called “targeted counseling and testing.” While targeting can be done according to levels of risk behavior, counseling and testing services can also be targeted by focusing on geographic areas (e.g., cities) with high levels of HIV infection, or focusing on different types of clinics that serve persons at high risk of HIV infection and/or with little routine access to health care (such as sexually transmitted disease or drug treatment clinics, emergency rooms, or medical clinics in prison settings).
Why Was This Study Done?
The researcher, David Holtgrave, wanted to know which of these two different approaches would be better at reaching people with undiagnosed HIV infection over the course of a one-year period. He also wanted to know the costs of each approach, and which might be better at curbing the spread of HIV.
What Did the Researcher Do and Find?
He used two research techniques. One is called “scenario analysis,” which involves trying to forecast the consequences of several different possible scenarios. The other is called “cost-effectiveness analysis,” which involves comparing the costs and effects of two or more different courses of action.
According to Dr. Holtgrave's analysis, opt-out testing might reach 23% of those people who are currently unaware that they are HIV positive. The program might also prevent 9% of the 40,000 new HIV infections that occur each year in the US. The cost of averting one new infection would be US$237,149. In contrast, targeted counseling and testing might identify about 75% of people in the US now unaware they are living with HIV infection, and prevent about 36% of the new HIV infections. The cost of averting one new infection would be US$59,383. Even when the author changed several assumptions in his analysis (e.g., assumptions about levels of HIV infection or the effectiveness of counseling), he found that targeted counseling and testing still performed better (so the results are “robust” across a variety of such assumptions).
What Do These Findings Mean?
These findings suggest that targeted counseling and testing would be better than opt-out testing for reaching people with undiagnosed HIV infection and for helping to stop the spread of the virus. Opt-out testing, says the author, might even make some people increase their risky behavior. For example, if someone is injecting drugs, is given an opt-out HIV test, but is never questioned about substance use or counseled, and gets an HIV-negative result, they could easily conclude that their drug injecting is not putting them at risk of becoming HIV positive.
However, it is important to note that this study has a major limitation in that it tried to predict what might happen in the future—it did not study the actual impact of the two different types of testing on a group of people. Studies such as this one, which try to predict the future, are always based on a number of assumptions and these assumptions may turn out not to be true. So we should always be cautious in interpreting the results of a “scenario analysis.” In addition, because of the assumptions made in this study, these results are only directly applicable to the US population and hence the implications for other countries are not clear.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040194
In a related Perspective on this article, Ronald Valdiserri discusses the public health implications of the study
The CDC has a Web site with information on national HIV testing resources
In addition, the CDC has published its “Revised Recommendations for HIV Testing of Adults, Adolescents, and Pregnant Women in Health-Care Settings,” which lay out its proposal for opt-out testing
The international AIDS charity AVERT has a comprehensive page on HIV testing, including information on the reasons to have a test and what the test involves
Johns Hopkins University is host to a site that provides extensive information on HIV care and treatment
The University of California at San Francisco maintains HIV InSite, an authoritative Web site covering topics such as HIV prevention, care, and policy
doi:10.1371/journal.pmed.0040194
PMCID: PMC1891318  PMID: 17564488
12.  International Breastfeeding Journal: Introducing a new journal 
International Breastfeeding Journal is a new open access peer-reviewed journal with a multidisciplinary focus. The aim of International Breastfeeding Journal is to contribute to understanding all aspects of breastfeeding. Breastfeeding is recognized as an important public health issue with enormous social and economic implications. In order to help women breastfeed successfully there is a need to understand both the physiology of lactation and the social and cultural context within which breastfeeding occurs. International Breastfeeding Journal invites manuscripts from around the world, which address all of these aspects, including the impediments to breastfeeding, the health effects of not breastfeeding for infants and their mothers, and the management of breastfeeding problems.
doi:10.1186/1746-4358-1-1
PMCID: PMC1436019  PMID: 16722586
13.  Estimating the Number of Paediatric Fevers Associated with Malaria Infection Presenting to Africa's Public Health Sector in 2007 
PLoS Medicine  2010;7(7):e1000301.
Peter Gething and colleagues compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites.
Background
As international efforts to increase the coverage of artemisinin-based combination therapy in public health sectors gather pace, concerns have been raised regarding their continued indiscriminate presumptive use for treating all childhood fevers. The availability of rapid-diagnostic tests to support practical and reliable parasitological diagnosis provides an opportunity to improve the rational treatment of febrile children across Africa. However, the cost effectiveness of diagnosis-based treatment polices will depend on the presumed numbers of fevers harbouring infection. Here we compute the number of fevers likely to present to public health facilities in Africa and the estimated number of these fevers likely to be infected with Plasmodium falciparum malaria parasites.
Methods and Findings
We assembled first administrative-unit level data on paediatric fever prevalence, treatment-seeking rates, and child populations. These data were combined in a geographical information system model that also incorporated an adjustment procedure for urban versus rural areas to produce spatially distributed estimates of fever burden amongst African children and the subset likely to present to public sector clinics. A second data assembly was used to estimate plausible ranges for the proportion of paediatric fevers seen at clinics positive for P. falciparum in different endemicity settings. We estimated that, of the 656 million fevers in African 0–4 y olds in 2007, 182 million (28%) were likely to have sought treatment in a public sector clinic of which 78 million (43%) were likely to have been infected with P. falciparum (range 60–103 million).
Conclusions
Spatial estimates of childhood fevers and care-seeking rates can be combined with a relational risk model of infection prevalence in the community to estimate the degree of parasitemia in those fevers reaching public health facilities. This quantification provides an important baseline comparison of malarial and nonmalarial fevers in different endemicity settings that can contribute to ongoing scientific and policy debates about optimum clinical and financial strategies for the introduction of new diagnostics. These models are made publicly available with the publication of this paper.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Malaria —an infectious parasitic disease transmitted to people through the bite of an infected mosquito —kills about one million people (mainly children living in sub-Saharan Africa) every year. Although several parasites cause malaria, Plasmodium falciparum is responsible for most of these deaths. For the past 50 years, the main treatments for P. falciparum malaria have been chloroquine and sulfadoxine/pyrimethamine. Unfortunately, parasitic resistance to these “monotherapies” is now widespread and there has been a global upsurge in the illness and deaths caused by P. falciparum. To combat this increase, the World Health Organization recommends artemisinin combination therapy (ACT) for P. falciparum malaria in all regions with drug-resistant malaria. In ACT, artemisinin derivatives (new, fast-acting antimalarial drugs) are used in combination with another antimalarial to reduce the chances of P. falciparum becoming resistant to either drug.
Why Was This Study Done?
All African countries at risk of P. falciparum have now adopted ACT as first-line therapy for malaria in their public clinics. However, experts are concerned that ACT is often given to children who don't actually have malaria because, in many parts of Africa, health care workers assume that all childhood fevers are malaria. This practice, which became established when diagnostic facilities for malaria were very limited, increases the chances of P. falciparum becoming resistant to ACT, wastes limited drug stocks, and means that many ill children are treated inappropriately. Recently, however, rapid diagnostic tests for malaria have been developed and there have been calls to expand their use to improve the rational treatment of African children with fever. Before such an expansion is initiated, it is important to know how many African children develop fever each year, how many of these ill children attend public clinics, and what proportion of them is likely to have malaria. Unfortunately, this type of information is incompletely or unreliably collected in many parts of Africa. In this study, therefore, the researchers use a mathematical model to estimate the number of childhood fevers associated with malaria infection that presented to Africa's public clinics in 2007 from survey data.
What Did the Researchers Do and Find?
The researchers used survey data on the prevalence (the proportion of a population with a specific disease) of childhood fever and on treatment-seeking behavior and data on child populations to map the distribution of fever among African children and the likelihood of these children attending public clinics for treatment. They then used a recent map of the distribution of P. falciparum infection risk to estimate what proportion of children with fever who attended clinics were likely to have had malaria in different parts of Africa. In 2007, the researchers estimate, 656 million cases of fever occurred in 0–4-year-old African children, 182 million were likely to have sought treatment in a public clinic, and 78 million (just under half of the cases that attended a clinic with fever) were likely to have been infected with P. falciparum. Importantly, there were marked geographical differences in the likelihood of children with fever presenting at public clinics being infected with P. falciparum. So, for example, whereas nearly 60% of the children attending public clinics with fever in Burkino Faso were likely to have had malaria, only 15% of similar children in Kenya were likely to have had this disease.
What Do These Findings Mean?
As with all mathematical models, the accuracy of these findings depends on the assumptions included in the model and on the data fed into it. Nevertheless, these findings provide a map of the prevalence of malarial and nonmalarial childhood fevers across sub-Saharan Africa and an indication of how many of the children with fever reaching public clinics are likely to have malaria and would therefore benefit from ACT. The finding that in some countries more than 80% of children attending public clinics with fever probably don't have malaria highlights the potential benefits of introducing rapid diagnostic testing for malaria. Furthermore, these findings can now be used to quantify the resources needed for and the potential clinical benefits of different policies for the introduction of rapid diagnostic testing for malaria across Africa.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000301.
Information is available from the World Health Organization on malaria (in several languages) and on rapid diagnostic tests for malaria
The US Centers for Disease Control and Prevention provide information on malaria (in English and Spanish)
MedlinePlus provides links to additional information on malaria (in English and Spanish)
Information on the global mapping of malaria is available at the Malaria Atlas Project
Information is available from the Roll Back Malaria Partnership on the global control of malaria (in English and French) and on artemisinin combination therapy
doi:10.1371/journal.pmed.1000301
PMCID: PMC2897768  PMID: 20625548
14.  Representations of OxyContin in North American newspapers and medical journals 
Following the approval of OxyContin (Purdue Pharma, Canada) for medical use, the media began to report the use of OxyContin as a street drug, representing the phenomenon as a social problem. Meanwhile, the pain medicine community has criticized the inaccurate and one-sided media coverage of the OxyContin problem. The authors of this study aimed to contribute to an understanding of both sides of this controversy by analyzing the coverage of OxyContin in newspapers and medical journals. The analyses revealed inconsistent messages about the drug from physicians in the news media and in medical journals, which has likely contributed to the drug’s perception as a social problem. The authors suggest ways to address the lack of medical consensus surrounding OxyContin. The results of this study may help resolve the concerns and conflicts surrounding this drug and other opioids.
BACKGROUND:
There are public concerns regarding OxyContin (Purdue Pharma, Canada) and charges within the pain medicine community that media coverage of the drug has been biased.
OBJECTIVE:
To analyze and compare representations of OxyContin in medical journals and North American newspapers in an attempt to shed light on how each contributes to the ‘social problem’ associated with OxyContin.
METHODS:
Using searches of newspaper and medical literature databases, two samples were drawn: 924 stories published between 1995 and 2005 in 27 North American newspapers, and 197 articles published between 1995 and 2007 in 33 medical journals in the fields of addiction/substance abuse, pain/anesthesiology and general/internal medicine. The foci, themes, perspectives represented and evaluations of OxyContin presented in these texts were analyzed statistically.
RESULTS:
Newspaper coverage of OxyContin emphasized negative evaluations of the drug, focusing on abuse, addiction, crime and death rather than the use of OxyContin for the legitimate treatment of pain. Newspaper stories most often conveyed the perspectives of law enforcement and courts, and much less often represented the perspectives of physicians. However, analysis of physician perspectives represented in newspaper stories and in medical journals revealed a high degree of inconsistency, especially across the fields of pain medicine and addiction medicine.
CONCLUSION:
The prevalence of negative representations of OxyContin is often blamed on biased media coverage and an ignorant public. However, the proliferation of inconsistent messages regarding the drug from physicians plays a role in the drug’s persistent status as a social problem.
PMCID: PMC3202377  PMID: 22059195
Media; Opioids; OxyContin; Public opinion; Social issues; Sociology
15.  Levels of evidence: a comparison between top medical journals and general pediatric journals 
BMC Pediatrics  2015;15:3.
Background
Given the large number of publications in all fields of practice, it is essential that clinicians focus on the resources that provide the highest level of evidence (LOE). We sought to determine the LOE that exists in the field of pediatrics, present in the general pediatric as well as high impact clinical literature.
Methods
Clinical pediatric literature, published between April 2011 and March 2012 inclusive in high-impact clinical journals (HICJ) (New England Journal of Medicine, Journal of the American Medical Association, & The Lancet) and the highest-impact general pediatric journals (GPJ) (Pediatrics, Journal of Pediatrics, & Archives of Pediatrics & Adolescent Medicine), was assessed. In addition to the LOE, articles were evaluated on criteria including subspecialty within pediatrics, number of authors, number of centers, and other parameters. Eligible level I randomized control trials were appraised using the Consolidated Standards of Reporting Trials (CONSORT) guidelines.
Results
Of 6511 articles screened, 804 met inclusion criteria (68 in HICJ and 736 in GPJ). On average, LOE in pediatrics-focused articles within The Lancet were significantly higher than all GPJ (p < 0.05). Average CONSORT scores were significantly higher in HICJ vs. GPJ (15.2 vs. 13.6, respectively, p < 0.001).
Conclusions
LOE and quality of randomized control trials within the pediatric field is highest within HICJ, however, only represent a small proportion of data published. Following CONSORT criteria, and promoting studies of high LOE may allow authors and readers to turn to journals and articles of greater clinical impact.
doi:10.1186/s12887-015-0324-9
PMCID: PMC4336754
Evidence-based medicine; Data quality; Journal impact factor
16.  Global Mortality Estimates for the 2009 Influenza Pandemic from the GLaMOR Project: A Modeling Study 
PLoS Medicine  2013;10(11):e1001558.
Lone Simonsen and colleagues use a two-stage statistical modeling approach to estimate the global mortality burden of the 2009 influenza pandemic from mortality data obtained from multiple countries.
Please see later in the article for the Editors' Summary
Background
Assessing the mortality impact of the 2009 influenza A H1N1 virus (H1N1pdm09) is essential for optimizing public health responses to future pandemics. The World Health Organization reported 18,631 laboratory-confirmed pandemic deaths, but the total pandemic mortality burden was substantially higher. We estimated the 2009 pandemic mortality burden through statistical modeling of mortality data from multiple countries.
Methods and Findings
We obtained weekly virology and underlying cause-of-death mortality time series for 2005–2009 for 20 countries covering ∼35% of the world population. We applied a multivariate linear regression model to estimate pandemic respiratory mortality in each collaborating country. We then used these results plus ten country indicators in a multiple imputation model to project the mortality burden in all world countries. Between 123,000 and 203,000 pandemic respiratory deaths were estimated globally for the last 9 mo of 2009. The majority (62%–85%) were attributed to persons under 65 y of age. We observed a striking regional heterogeneity, with almost 20-fold higher mortality in some countries in the Americas than in Europe. The model attributed 148,000–249,000 respiratory deaths to influenza in an average pre-pandemic season, with only 19% in persons <65 y. Limitations include lack of representation of low-income countries among single-country estimates and an inability to study subsequent pandemic waves (2010–2012).
Conclusions
We estimate that 2009 global pandemic respiratory mortality was ∼10-fold higher than the World Health Organization's laboratory-confirmed mortality count. Although the pandemic mortality estimate was similar in magnitude to that of seasonal influenza, a marked shift toward mortality among persons <65 y of age occurred, so that many more life-years were lost. The burden varied greatly among countries, corroborating early reports of far greater pandemic severity in the Americas than in Australia, New Zealand, and Europe. A collaborative network to collect and analyze mortality and hospitalization surveillance data is needed to rapidly establish the severity of future pandemics.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Every winter, millions of people catch influenza—a viral infection of the airways—and hundreds of thousands of people (mainly elderly individuals) die as a result. These seasonal epidemics occur because small but frequent changes in the influenza virus mean that the immune response produced by infection with one year's virus provides only partial protection against the next year's virus. Influenza viruses also occasionally emerge that are very different. Human populations have virtually no immunity to these new viruses, which can start global epidemics (pandemics) that kill millions of people. The most recent influenza pandemic, which was first recognized in Mexico in March 2009, was caused by the 2009 influenza A H1N1 pandemic (H1N1pdm09) virus. This virus spread rapidly, and on 11 June 2009, the World Health Organization (WHO) declared that an influenza pandemic was underway. H1N1pdm09 caused a mild disease in most people it infected, but by the time WHO announced that the pandemic was over (10 August 2010), there had been 18,632 laboratory-confirmed deaths from H1N1pdm09.
Why Was This Study Done?
The modest number of laboratory-confirmed H1N1pdm09 deaths has caused commentators to wonder whether the public health response to H1N1pdm09 was excessive. However, as is the case with all influenza epidemics, the true mortality (death) burden from H1N1pdm09 is substantially higher than these figures indicate because only a minority of influenza-related deaths are definitively diagnosed by being confirmed in laboratory. Many influenza-related deaths result from secondary bacterial infections or from exacerbation of preexisting chronic conditions, and are not recorded as related to influenza infection. A more complete assessment of the impact of H1N1pdm09 on mortality is essential for the optimization of public health responses to future pandemics. In this modeling study (the Global Pandemic Mortality [GLaMOR] project), researchers use a two-stage statistical modeling approach to estimate the global mortality burden of the 2009 influenza pandemic from mortality data obtained from multiple countries.
What Did the Researchers Do and Find?
The researchers obtained weekly virology data from the World Health Organization FluNet database and national influenza centers to identify influenza active periods, and obtained weekly national underlying cause-of-death time series for 2005–2009 from collaborators in more than 20 countries (35% of the world's population). They used a multivariate linear regression model to measure the numbers and rates of pandemic influenza respiratory deaths in each of these countries. Then, in the second stage of their analysis, they used a multiple imputation model that took into account country-specific geographical, economic, and health indicators to project the single-country estimates to all world countries. The researchers estimated that between 123,000 and 203,000 pandemic influenza respiratory deaths occurred globally from 1 April through 31 December 2009. Most of these deaths (62%–85%) occurred in people younger than 65 years old. There was a striking regional heterogeneity in deaths, with up to 20-fold higher mortality in Central and South American countries than in European countries. Finally, the model attributed 148,000–249,000 respiratory deaths to influenza in an average pre-pandemic season. Notably, only 19% of these deaths occurred in people younger than 65 years old.
What Do These Findings Mean?
These findings suggest that respiratory mortality from the 2009 influenza pandemic was about 10-fold higher than laboratory-confirmed mortality. The true total mortality burden is likely to be even higher because deaths that occurred late in the winter of 2009–2010 and in later pandemic waves were missed in this analysis, and only pandemic influenza deaths that were recorded as respiratory deaths were included. The lack of single-country estimates from low-income countries may also limit the accuracy of these findings. Importantly, although the researchers' estimates of mortality from H1N1pdm09 and from seasonal influenza were of similar magnitude, the shift towards mortality among younger people means that more life-years were lost during the 2009 influenza pandemic than during an average pre-pandemic influenza season. Although the methods developed by the GLaMOR project can be used to make robust and comparable mortality estimates in future influenza pandemics, the lack of timeliness of such estimates needs to be remedied. One potential remedy, suggest the researchers, would be to establish a collaborative network that analyzes timely hospitalization and/or mortality data provided by sentinel countries. Such a network should be able to provide the rapid and reliable data about the severity of pandemic threats that is needed to guide public health policy decisions.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001558.
The US Centers for Disease Control and Prevention provides information about influenza for patients and professionals, including archived information on H1N1pdm09
Flu.gov, a US government website, provides access to information on seasonal and pandemic influenza H1N1pdm09
The World Health Organization provides information on influenza and on the global response to H1N1pdm09, including a publication on the evolution of H1N1pdm09 (some information in several languages). Information on FluNet, a global tool for influenza surveillance, is also available
Public Health England provides information on pandemic influenza and archived information on H1N1pdm09
More information for patients about H1N1pdm09 is available through Choices, an information resource provided by the UK National Health Service
More information about the GLaMOR project is available
doi:10.1371/journal.pmed.1001558
PMCID: PMC3841239  PMID: 24302890
17.  Does the development of new medicinal products in the European Union address global and regional health concerns? 
Background
Since 1995, approval for many new medicinal products has been obtained through a centralized procedure in the European Union. In recent years, the use of summary measures of population health has become widespread. We investigated whether efforts to develop innovative medicines are focusing on the most relevant conditions from a global public health perspective.
Methods
We reviewed the information on new medicinal products approved by centralized procedure from 1995 to 2009, information that is available to the public in the European Commission Register of medicinal products and the European Public Assessment Reports from the European Medicines Agency. Morbidity and mortality data were included for each disease group, according to the Global Burden of Disease project. We evaluated the association between authorized medicinal products and burden of disease measures based on disability-adjusted life years (DALYs) in the European Union and worldwide.
Results
We considered 520 marketing authorizations for medicinal products and 338 active ingredients. New authorizations were seen to increase over the period analyzed. There was a positive, high correlation between DALYs and new medicinal product development (ρ = 0.619, p = 0.005) in the European Union, and a moderate correlation for middle-low-income countries (ρ = 0.497, p = 0.030) and worldwide (ρ = 0.490, p = 0.033). The most neglected conditions at the European level (based on their attributable health losses) were neuropsychiatric diseases, cardiovascular diseases, respiratory diseases, sense organ conditions, and digestive diseases, while globally, they were perinatal conditions, respiratory infections, sense organ conditions, respiratory diseases, and digestive diseases.
Conclusions
We find that the development of new medicinal products is higher for some diseases than others. Pharmaceutical industry leaders and policymakers are invited to consider the implications of this imbalance by establishing work plans that allow for the setting of future priorities from a public health perspective.
doi:10.1186/1478-7954-8-34
PMCID: PMC3017015  PMID: 21172012
18.  An Epidemiological Network Model for Disease Outbreak Detection 
PLoS Medicine  2007;4(6):e210.
Background
Advanced disease-surveillance systems have been deployed worldwide to provide early detection of infectious disease outbreaks and bioterrorist attacks. New methods that improve the overall detection capabilities of these systems can have a broad practical impact. Furthermore, most current generation surveillance systems are vulnerable to dramatic and unpredictable shifts in the health-care data that they monitor. These shifts can occur during major public events, such as the Olympics, as a result of population surges and public closures. Shifts can also occur during epidemics and pandemics as a result of quarantines, the worried-well flooding emergency departments or, conversely, the public staying away from hospitals for fear of nosocomial infection. Most surveillance systems are not robust to such shifts in health-care utilization, either because they do not adjust baselines and alert-thresholds to new utilization levels, or because the utilization shifts themselves may trigger an alarm. As a result, public-health crises and major public events threaten to undermine health-surveillance systems at the very times they are needed most.
Methods and Findings
To address this challenge, we introduce a class of epidemiological network models that monitor the relationships among different health-care data streams instead of monitoring the data streams themselves. By extracting the extra information present in the relationships between the data streams, these models have the potential to improve the detection capabilities of a system. Furthermore, the models' relational nature has the potential to increase a system's robustness to unpredictable baseline shifts. We implemented these models and evaluated their effectiveness using historical emergency department data from five hospitals in a single metropolitan area, recorded over a period of 4.5 y by the Automated Epidemiological Geotemporal Integrated Surveillance real-time public health–surveillance system, developed by the Children's Hospital Informatics Program at the Harvard-MIT Division of Health Sciences and Technology on behalf of the Massachusetts Department of Public Health. We performed experiments with semi-synthetic outbreaks of different magnitudes and simulated baseline shifts of different types and magnitudes. The results show that the network models provide better detection of localized outbreaks, and greater robustness to unpredictable shifts than a reference time-series modeling approach.
Conclusions
The integrated network models of epidemiological data streams and their interrelationships have the potential to improve current surveillance efforts, providing better localized outbreak detection under normal circumstances, as well as more robust performance in the face of shifts in health-care utilization during epidemics and major public events.
Most surveillance systems are not robust to shifts in health care utilization. Ben Reis and colleagues developed network models that detected localized outbreaks better and were more robust to unpredictable shifts.
Editors' Summary
Background.
The main task of public-health officials is to promote health in communities around the world. To do this, they need to monitor human health continually, so that any outbreaks (epidemics) of infectious diseases (particularly global epidemics or pandemics) or any bioterrorist attacks can be detected and dealt with quickly. In recent years, advanced disease-surveillance systems have been introduced that analyze data on hospital visits, purchases of drugs, and the use of laboratory tests to look for tell-tale signs of disease outbreaks. These surveillance systems work by comparing current data on the use of health-care resources with historical data or by identifying sudden increases in the use of these resources. So, for example, more doctors asking for tests for salmonella than in the past might presage an outbreak of food poisoning, and a sudden rise in people buying over-the-counter flu remedies might indicate the start of an influenza pandemic.
Why Was This Study Done?
Existing disease-surveillance systems don't always detect disease outbreaks, particularly in situations where there are shifts in the baseline patterns of health-care use. For example, during an epidemic, people might stay away from hospitals because of the fear of becoming infected, whereas after a suspected bioterrorist attack with an infectious agent, hospitals might be flooded with “worried well” (healthy people who think they have been exposed to the agent). Baseline shifts like these might prevent the detection of increased illness caused by the epidemic or the bioterrorist attack. Localized population surges associated with major public events (for example, the Olympics) are also likely to reduce the ability of existing surveillance systems to detect infectious disease outbreaks. In this study, the researchers developed a new class of surveillance systems called “epidemiological network models.” These systems aim to improve the detection of disease outbreaks by monitoring fluctuations in the relationships between information detailing the use of various health-care resources over time (data streams).
What Did the Researchers Do and Find?
The researchers used data collected over a 3-y period from five Boston hospitals on visits for respiratory (breathing) problems and for gastrointestinal (stomach and gut) problems, and on total visits (15 data streams in total), to construct a network model that included all the possible pair-wise comparisons between the data streams. They tested this model by comparing its ability to detect simulated disease outbreaks implanted into data collected over an additional year with that of a reference model based on individual data streams. The network approach, they report, was better at detecting localized outbreaks of respiratory and gastrointestinal disease than the reference approach. To investigate how well the network model dealt with baseline shifts in the use of health-care resources, the researchers then added in a large population surge. The detection performance of the reference model decreased in this test, but the performance of the complete network model and of models that included relationships between only some of the data streams remained stable. Finally, the researchers tested what would happen in a situation where there were large numbers of “worried well.” Again, the network models detected disease outbreaks consistently better than the reference model.
What Do These Findings Mean?
These findings suggest that epidemiological network systems that monitor the relationships between health-care resource-utilization data streams might detect disease outbreaks better than current systems under normal conditions and might be less affected by unpredictable shifts in the baseline data. However, because the tests of the new class of surveillance system reported here used simulated infectious disease outbreaks and baseline shifts, the network models may behave differently in real-life situations or if built using data from other hospitals. Nevertheless, these findings strongly suggest that public-health officials, provided they have sufficient computer power at their disposal, might improve their ability to detect disease outbreaks by using epidemiological network systems alongside their current disease-surveillance systems.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040210.
Wikipedia pages on public health (note that Wikipedia is a free online encyclopedia that anyone can edit, and is available in several languages)
A brief description from the World Health Organization of public-health surveillance (in English, French, Spanish, Russian, Arabic, and Chinese)
A detailed report from the US Centers for Disease Control and Prevention called “Framework for Evaluating Public Health Surveillance Systems for the Early Detection of Outbreaks”
The International Society for Disease Surveillance Web site
doi:10.1371/journal.pmed.0040210
PMCID: PMC1896205  PMID: 17593895
19.  Comprehensive effective and efficient global public health surveillance 
BMC Public Health  2010;10(Suppl 1):S3.
At a crossroads, global public health surveillance exists in a fragmented state. Slow to detect, register, confirm, and analyze cases of public health significance, provide feedback, and communicate timely and useful information to stakeholders, global surveillance is neither maximally effective nor optimally efficient. Stakeholders lack a globa surveillance consensus policy and strategy; officials face inadequate training and scarce resources.
Three movements now set the stage for transformation of surveillance: 1) adoption by Member States of the World Health Organization (WHO) of the revised International Health Regulations (IHR[2005]); 2) maturation of information sciences and the penetration of information technologies to distal parts of the globe; and 3) consensus that the security and public health communities have overlapping interests and a mutual benefit in supporting public health functions. For these to enhance surveillance competencies, eight prerequisites should be in place: politics, policies, priorities, perspectives, procedures, practices, preparation, and payers.
To achieve comprehensive, global surveillance, disparities in technical, logistic, governance, and financial capacities must be addressed. Challenges to closing these gaps include the lack of trust and transparency; perceived benefit at various levels; global governance to address data power and control; and specified financial support from globa partners.
We propose an end-state perspective for comprehensive, effective and efficient global, multiple-hazard public health surveillance and describe a way forward to achieve it. This end-state is universal, global access to interoperable public health information when it’s needed, where it’s needed. This vision mitigates the tension between two fundamental human rights: first, the right to privacy, confidentiality, and security of personal health information combined with the right of sovereign, national entities to the ownership and stewardship of public health information; and second, the right of individuals to access real-time public health information that might impact their lives.
The vision can be accomplished through an interoperable, global public health grid. Adopting guiding principles, the global community should circumscribe the overlapping interest, shared vision, and mutual benefit between the security and public health communities and define the boundaries. A global forum needs to be established to guide the consensus governance required for public health information sharing in the 21st century.
doi:10.1186/1471-2458-10-S1-S3
PMCID: PMC3005575  PMID: 21143825
20.  Barriers to Provider-Initiated Testing and Counselling for Children in a High HIV Prevalence Setting: A Mixed Methods Study 
PLoS Medicine  2014;11(5):e1001649.
Rashida Ferrand and colleagues combine quantitative and qualitative methods to investigate HIV prevalence among older children receiving primary care in Harare, Zimbabwe, and reasons why providers did not pursue testing.
Please see later in the article for the Editors' Summary
Background
There is a substantial burden of HIV infection among older children in sub-Saharan Africa, the majority of whom are diagnosed after presentation with advanced disease. We investigated the provision and uptake of provider-initiated HIV testing and counselling (PITC) among children in primary health care facilities, and explored health care worker (HCW) perspectives on providing HIV testing to children.
Methods and Findings
Children aged 6 to 15 y attending six primary care clinics in Harare, Zimbabwe, were offered PITC, with guardian consent and child assent. The reasons why testing did not occur in eligible children were recorded, and factors associated with HCWs offering and children/guardians refusing HIV testing were investigated using multivariable logistic regression. Semi-structured interviews were conducted with clinic nurses and counsellors to explore these factors. Among 2,831 eligible children, 2,151 (76%) were offered PITC, of whom 1,534 (54.2%) consented to HIV testing. The main reasons HCWs gave for not offering PITC were the perceived unsuitability of the accompanying guardian to provide consent for HIV testing on behalf of the child and lack of availability of staff or HIV testing kits. Children who were asymptomatic, older, or attending with a male or a younger guardian had significantly lower odds of being offered HIV testing. Male guardians were less likely to consent to their child being tested. 82 (5.3%) children tested HIV-positive, with 95% linking to care. Of the 940 guardians who tested with the child, 186 (19.8%) were HIV-positive.
Conclusions
The HIV prevalence among children tested was high, highlighting the need for PITC. For PITC to be successfully implemented, clear legislation about consent and guardianship needs to be developed, and structural issues addressed. HCWs require training on counselling children and guardians, particularly male guardians, who are less likely to engage with health care services. Increased awareness of the risk of HIV infection in asymptomatic older children is needed.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Over 3 million children globally are estimated to be living with HIV (the virus that causes AIDS). While HIV infection is most commonly spread through unprotected sex with an infected person, most HIV infections among children are the result of mother-to-child HIV transmission during pregnancy, delivery, or breastfeeding. Mother-to-child transmission can be prevented by administering antiretroviral therapy to mothers with HIV during pregnancy, delivery, and breast feeding, and to their newborn babies. According to a report by the Joint United Nations Programme on HIV/AIDS published in 2012, 92% of pregnant women with HIV were living in sub-Saharan Africa and just under 60% were receiving antiretroviral therapy. Consequently, sub-Saharan Africa is the region where most children infected with HIV live.
Why Was This Study Done?
If an opportunity to prevent mother-to-child transmission around the time of birth is missed, diagnosis of HIV infection in a child or adolescent is likely to depend on HIV testing in health care facilities. Health care provider–initiated HIV testing and counselling (PITC) for children is important in areas where HIV infection is common because earlier diagnosis allows children to benefit from care that can prevent the development of advanced HIV disease. Even if a child or adolescent appears to be in good health, access to care and antiretroviral therapy provides a health benefit to the individual over the long term. The administration of HIV testing (and counselling) to children relies not only on health care workers (HCWs) offering HIV testing but also on parents or guardians consenting for a child to be tested. However, more than 30% of children in countries with severe HIV epidemics are AIDS orphans, and economic conditions in these countries cause many adults to migrate for work, leaving children under the care of extended families. This study aimed to investigate the reasons for acceptance and rejection of PITC in primary health care settings in Harare, Zimbabwe. By exploring HCW perspectives on providing HIV testing to children and adolescents, the study also sought to gain insight into factors that could be hindering implementation of testing procedures.
What Did the Researchers Do and Find?
The researchers identified all children aged 6 to 15 years old at six primary care clinics in Harare, who were offered HIV testing as part of routine care between 22 January and 31 May 2013. Study fieldworkers collected data on numbers of child attendances, numbers offered testing, numbers who underwent HIV testing, and reasons why HIV testing did not occur. During the study 2,831 children attending the health clinics were eligible for PITC, and just over half (1,534, 54.2%) underwent HIV testing. Eighty-two children tested HIV-positive, and nearly all of them received counselling, medication, and follow-up care. HCWs offered the test to around 75% of those eligible. The most frequent explanation given by HCWs for a diagnostic test not being offered was that the child was accompanied by a guardian not appropriate for providing consent (401 occasions, 59%); Other reasons given were a lack of available counsellors or test kits and counsellors refusing to conduct the test. The likelihood of being offered the test was lower for children not exhibiting symptoms (such as persistent skin problems), older children, or those attending with a male or a younger guardian. In addition, over 100 guardians or parents provided consent but left before the child could be tested.
The researchers also conducted semi-structured interviews with 12 clinic nurses and counsellors (two from each clinic) to explore challenges to implementation of PITC. The researchers recorded the factors associated with testing not taking place, either when offered to eligible children or when HCWs declined to offer the test. The interviewees identified the frequent absence or unavailability of parents or legal guardians as an obstacle, and showed uncertainty or misconceptions around whether testing of the guardian was mandatory (versus recommended) and whether specifically a parent (if one was living) must provide consent. The interviews also revealed HCW concerns about the availability of adequate counselling and child services, and fears that a child might experience maltreatment if he or she tested positive. HCWs also noted long waiting times and test kits being out of stock as practical hindrances to testing.
What Do These Findings Mean?
Prevalence of HIV was high among the children tested, validating the need for PITC in sub-Saharan health care settings. Although 76% of eligible attendees were offered testing, the authors note that this is likely higher than in routine settings because the researchers were actively recording reasons for not offering testing and counselling, which may have encouraged heath care staff to offer PITC more often than usual. The researchers outline strategies that may improve PITC rates and testing acceptance for Zimbabwe and other sub-Saharan settings. These strategies include developing clear laws and guidance concerning guardianship and proxy consent when testing older children for HIV, training HCWs around these policies, strengthening legislation to address discrimination, and increasing public awareness about HIV infection in older children.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001649.
This study is further discussed in a PLOS Medicine Perspective by Davies and Kalk
The Joint United Nations Programme on HIV/AIDS publishes an annual report on the global AIDS epidemic, which provides information on progress towards eliminating new HIV infections
The World Health Organization has more information on mother-to-child transmission of HIV
The World Health Organization's website also has information about treatment for children living with HIV
Personal stories about living with HIV/AIDS, including stories from young people infected with HIV, are available through Avert, through NAM/aidsmap, and through the charity website Healthtalkonline
doi:10.1371/journal.pmed.1001649
PMCID: PMC4035250  PMID: 24866209
21.  Public accessibility of biomedical articles from PubMed Central reduces journal readership—retrospective cohort analysis 
The FASEB Journal  2013;27(7):2536-2541.
Does PubMed Central—a government-run digital archive of biomedical articles—compete with scientific society journals? A longitudinal, retrospective cohort analysis of 13,223 articles (5999 treatment, 7224 control) published in 14 society-run biomedical research journals in nutrition, experimental biology, physiology, and radiology between February 2008 and January 2011 reveals a 21.4% reduction in full-text hypertext markup language (HTML) article downloads and a 13.8% reduction in portable document format (PDF) article downloads from the journals' websites when U.S. National Institutes of Health-sponsored articles (treatment) become freely available from the PubMed Central repository. In addition, the effect of PubMed Central on reducing PDF article downloads is increasing over time, growing at a rate of 1.6% per year. There was no longitudinal effect for full-text HTML downloads. While PubMed Central may be providing complementary access to readers traditionally underserved by scientific journals, the loss of article readership from the journal website may weaken the ability of the journal to build communities of interest around research papers, impede the communication of news and events to scientific society members and journal readers, and reduce the perceived value of the journal to institutional subscribers.—Davis, P. M. Public accessibility of biomedical articles from PubMed Central reduces journal readership—retrospective cohort analysis.
doi:10.1096/fj.13-229922
PMCID: PMC3688741  PMID: 23554455
digital repositories; downloads; open access; scientific publishing
22.  Cost-Effectiveness of Rapid Syphilis Screening in Prenatal HIV Testing Programs in Haiti 
PLoS Medicine  2007;4(5):e183.
Background
New rapid syphilis tests permit simple and immediate diagnosis and treatment at a single clinic visit. We compared the cost-effectiveness, projected health outcomes, and annual cost of screening pregnant women using a rapid syphilis test as part of scaled-up prenatal testing to prevent mother-to-child HIV transmission in Haiti.
Methods and Findings
A decision analytic model simulated health outcomes and costs separately for pregnant women in rural and urban areas. We compared syphilis syndromic surveillance (rural standard of care), rapid plasma reagin test with results and treatment at 1-wk follow-up (urban standard of care), and a new rapid test with immediate results and treatment. Test performance data were from a World Health Organization–Special Programme for Research and Training in Tropical Diseases field trial conducted at the GHESKIO Center Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes in Port-au-Prince. Health outcomes were projected using historical data on prenatal syphilis treatment efficacy and included disability-adjusted life years (DALYs) of newborns, congenital syphilis cases, neonatal deaths, and stillbirths. Cost-effectiveness ratios are in US dollars/DALY from a societal perspective; annual costs are in US dollars from a payer perspective. Rapid testing with immediate treatment has a cost-effectiveness ratio of $6.83/DALY in rural settings and $9.95/DALY in urban settings. Results are sensitive to regional syphilis prevalence, rapid test sensitivity, and the return rate for follow-up visits. Integrating rapid syphilis testing into a scaled-up national HIV testing and prenatal care program would prevent 1,125 congenital syphilis cases and 1,223 stillbirths or neonatal deaths annually at a cost of $525,000.
Conclusions
In Haiti, integrating a new rapid syphilis test into prenatal care and HIV testing would prevent congenital syphilis cases and stillbirths, and is cost-effective. A similar approach may be beneficial in other resource-poor countries that are scaling up prenatal HIV testing.
Analyzing data from Haiti, Bruce Schackman and colleagues report that scale-up of prenatal HIV testing programs provides a cost-effective opportunity to prevent congenital syphilis through rapid testing.
Editors' Summary
Background.
Congenital syphilis (syphilis that is passed on from a woman infected with the disease to her unborn baby) is a major preventable public health problem. Around half of all pregnancies among women infected with syphilis result in stillbirth or death of the baby shortly after birth. However, it should be possible to reduce the health burden of congenital syphilis if infections among pregnant women could be quickly and accurately diagnosed. In resource-poor countries, many syphilis infections go undiagnosed, because the tests that are normally used involve sending samples away to a laboratory for processing. This means that the diagnosis can only be confirmed, and treatment started, at the next available visit. As a result, there is a delay in starting antibiotic treatment, and some women may never receive their intended treatment at all if they cannot return for their follow-up visit. However, new tests are available that don't involve cold storage of reagents or electrical equipment, and these can be used to give an immediate result about syphilis infection even in rural or resource-poor settings. Currently, global initiatives are underway to ensure many more pregnant women are tested for HIV and to reduce the risk of HIV being passed on from a woman to her baby. These initiatives could provide an important opportunity for carrying out widespread immediate screening for syphilis during pregnancy as well. Such screening might then help reduce infant deaths substantially.
Why Was This Study Done?
Field trials evaluating rapid syphilis tests have already been carried out by the World Health Organization's Special Programme for Research and Training in Tropical Diseases. One such trial, carried out in Port-au-Prince, Haiti, evaluated the success of three different rapid syphilis tests as compared to two “gold standard” tests (older tests that are generally considered reliable, but which don't give an immediate result). These researchers wanted to use data from these trials to compare costs and predicted health outcomes of including different types of syphilis screening as part of scaled-up prenatal care. Specifically, the researchers wanted to find out whether including rapid syphilis testing as part of universal prenatal care would be cost-effective and whether it would reduce the rate of stillbirths and congenital syphilis.
What Did the Researchers Do and Find?
This research was based on data from the field trials previously carried out in Haiti. The data from these trials were used to create a model comparing three different strategies for screening pregnant women for syphilis infections. The three strategies were as follows: checking for the symptoms of syphilis (assumed to be the standard of care in rural areas); standard testing for antibody response to the syphilis bacterium, after which treatment can be provided at follow-up a week later (assumed to be the standard of care in urban areas); and, finally, rapid testing that gives an immediate result. For each strategy, the researchers predicted what the health outcomes would be. These outcomes are summarized in “disability-adjusted life years” (DALYs) that reflect the number of years of healthy life lost due to congenital syphilis among newborn babies, the number of stillbirths, and the number of neonatal deaths. Cost-effectiveness of each strategy was also worked out by dividing the additional costs of testing and treatment for each strategy by the number of DALYs avoided using that screening method compared to the next most expensive alternative. Under the model, urban and rural settings were looked at separately. Immediate testing was more expensive than either standard testing or checking for symptoms, but emerged as more cost-effective than standard testing in rural settings; the immediate test would cost an additional $7–$10 per disability-adjusted life year compared to the current rural or urban standard of care. The researchers predicted that if immediate syphilis testing were provided to all pregnant women in Haiti who currently have access to prenatal care, over 1,000 congenital syphilis cases would be avoided, along with over 1,000 stillbirths and neonatal deaths, at a yearly cost of $525,000.
What Do These Findings Mean?
This model suggests that including rapid syphilis testing as part of current global initiatives for preventing mother-to-child transmission of HIV could substantially reduce infant deaths. The strategy is also likely to be cost-effective.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040183.
MedlinePlus encyclopedia entry on congenital syphilis
Information from the World Health Organization about congenital syphilis, including information about screening programs and new screening tests
A report is also available from the Special Programme for Research and Training in Tropical Diseases regarding rapid syphilis tests
AVERT, an international AIDS charity, provides information about preventing mother-to-child transmission of HIV
doi:10.1371/journal.pmed.0040183
PMCID: PMC1880854  PMID: 17535105
23.  The Importance of Implementation Strategy in Scaling Up Xpert MTB/RIF for Diagnosis of Tuberculosis in the Indian Health-Care System: A Transmission Model 
PLoS Medicine  2014;11(7):e1001674.
Using a modelling approach, David Dowdy and colleagues investigate how different implementation strategies for Xpert MTB/RIF within the complex, fragmented healthcare system of India may affect tuberculosis control.
Please see later in the article for the Editors' Summary
Background
India has announced a goal of universal access to quality tuberculosis (TB) diagnosis and treatment. A number of novel diagnostics could help meet this important goal. The rollout of one such diagnostic, Xpert MTB/RIF (Xpert) is being considered, but if Xpert is used mainly for people with HIV or high risk of multidrug-resistant TB (MDR-TB) in the public sector, population-level impact may be limited.
Methods and Findings
We developed a model of TB transmission, care-seeking behavior, and diagnostic/treatment practices in India and explored the impact of six different rollout strategies. Providing Xpert to 40% of public-sector patients with HIV or prior TB treatment (similar to current national strategy) reduced TB incidence by 0.2% (95% uncertainty range [UR]: −1.4%, 1.7%) and MDR-TB incidence by 2.4% (95% UR: −5.2%, 9.1%) relative to existing practice but required 2,500 additional MDR-TB treatments and 60 four-module GeneXpert systems at maximum capacity. Further including 20% of unselected symptomatic individuals in the public sector required 700 systems and reduced incidence by 2.1% (95% UR: 0.5%, 3.9%); a similar approach involving qualified private providers (providers who have received at least some training in allopathic or non-allopathic medicine) reduced incidence by 6.0% (95% UR: 3.9%, 7.9%) with similar resource outlay, but only if high treatment success was assured. Engaging 20% of all private-sector providers (qualified and informal [providers with no formal medical training]) had the greatest impact (14.1% reduction, 95% UR: 10.6%, 16.9%), but required >2,200 systems and reliable treatment referral. Improving referrals from informal providers for smear-based diagnosis in the public sector (without Xpert rollout) had substantially greater impact (6.3% reduction) than Xpert scale-up within the public sector. These findings are subject to substantial uncertainty regarding private-sector treatment patterns, patient care-seeking behavior, symptoms, and infectiousness over time; these uncertainties should be addressed by future research.
Conclusions
The impact of new diagnostics for TB control in India depends on implementation within the complex, fragmented health-care system. Transformative strategies will require private/informal-sector engagement, adequate referral systems, improved treatment quality, and substantial resources.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Tuberculosis—a contagious bacterial disease that usually infects the lungs—is a global public health problem. Each year, about 8.7 million people develop active tuberculosis and about 1.4 million people die from the disease. Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is spread in airborne droplets when people with active disease cough or sneeze. The characteristic symptoms of tuberculosis are a persistent cough, fever, weight loss, and night sweats. Diagnostic tests for tuberculosis include sputum smear microscopy (microscopic analysis of mucus coughed up from the lungs), the growth of M. tuberculosis from sputum samples, and new molecular tests (for example, the automated Xpert MTB/RIF test) that rapidly and accurately detect M. tuberculosis in patient samples and determine its resistance to certain antibiotics. Tuberculosis can be cured by taking several antibiotics daily for at least six months, although the recent emergence of multidrug-resistant (MDR) tuberculosis is making the disease increasingly hard to treat.
Why Was This Study Done?
About 25% of all tuberculosis cases occur in India. Most people in India with underlying tuberculosis initially seek care for cough from the private health-care sector, which comprises informal providers with no formal medical training and providers with some training in mainstream or alternative medicine. Private providers rarely investigate for tuberculosis, and patients often move between providers, with long diagnostic delays. The public sector ultimately diagnoses and treats more than half of tuberculosis cases. However, the public sector relies on sputum smear microscopy, which misses half of cases, and the full diagnostic process from symptom onset to treatment initiation can take several months, during which time individuals remain infectious. Could the rollout of molecular diagnostic tests improve tuberculosis control in India? The Indian Revised National Tuberculosis Control Programme (RNTCP) is currently introducing the Xpert MTB/RIF test (Xpert) as a rapid method for drug susceptibility testing in the public sector in people at high risk of MDR tuberculosis, but is this the most effective rollout strategy? Here, the researchers use a mathematical transmission model to investigate the likely effects of the rollout of Xpert in India using different implementation strategies.
What Did the Researchers Do and Find?
The researchers explored the impact of several rollout strategies on the incidence of tuberculosis (the number of new cases of tuberculosis in the population per year) by developing a mathematical model of tuberculosis transmission, care-seeking behavior, and diagnostic/treatment practices in India. Compared to a baseline scenario of no improved diagnostic testing, provision of Xpert to 40% of public-sector patients at high risk of MDR tuberculosis (scenario 1, the current national strategy) reduced the incidence of tuberculosis by 0.2% and the incidence of MDR tuberculosis by 2.4%. Implementation of this strategy required 2,500 additional courses of MDR tuberculosis treatment and the continuous use of 60 Xpert machines, about half the machines procured in India during 2013. A scenario that added access to Xpert for 20% of all individuals with tuberculosis symptoms seeking diagnosis in the public sector and 20% of individuals seeking care from qualified private practitioners to scenario 1 reduced the incidence of tuberculosis by 14.1% compared to the baseline scenario but required more than 2,200 Xpert machines and reliable treatment referral. Notably, a scenario that encouraged informal providers to refer suspected tuberculosis cases to the public sector for smear-based diagnosis (no Xpert rollout) had a greater impact on the incidence of tuberculosis than Xpert scale-up within the public sector.
What Do These Findings Mean?
These findings are subject to considerable uncertainty because of the assumptions made in the transmission model about private-sector treatment patterns, patient care-seeking behavior, and infectiousness, and the quality of the data fed into the model. Nevertheless, these findings suggest that the rollout of Xpert (or other new diagnostic methods with similar characteristics) could substantially reduce the burden of tuberculosis due to poor diagnosis in India. Importantly, these findings highlight how the impact of Xpert rollout relies not only on the accuracy of the test but also on the behavior of patients and providers, the level of access to new tools, and the availability of treatment following diagnosis. Thus, to ensure that new diagnostic methods have the maximum impact on tuberculosis in India, it is necessary to engage the whole private health-care sector and to provide adequate referral systems, improved treatment quality, and increased resources across all health-care sectors.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001674.
The World Health Organization (WHO) provides information (in several languages) on all aspects of tuberculosis, including general information on tuberculosis diagnostics and specific information on the roll out of the Xpert MTB/RIF test; further information about WHO's endorsement of Xpert MTB/RIF is included in a Strategic and Technical Advisory Group for Tuberculosis report; the Global Tuberculosis Report 2013 provides information about tuberculosis around the world, including in India
The Stop TB Partnership is working towards tuberculosis elimination and provides patient stories about tuberculosis (in English and Spanish); the Tuberculosis Vaccine Initiative (a not-for-profit organization) also provides personal stories about tuberculosis
The US Centers for Disease Control and Prevention has information about tuberculosis and its diagnosis (in English and Spanish)
The US National Institute of Allergy and Infectious Diseases also has detailed information on all aspects of tuberculosis
TBC India provides information about tuberculosis control in India, including information on the RNTCP
The Initiative for Promoting Affordable and Quality TB Tests promotes WHO-endorsed TB tests in India
MedlinePlus has links to further information about tuberculosis (in English and Spanish)
doi:10.1371/journal.pmed.1001674
PMCID: PMC4098913  PMID: 25025235
24.  The Global Burden of Snakebite: A Literature Analysis and Modelling Based on Regional Estimates of Envenoming and Deaths 
PLoS Medicine  2008;5(11):e218.
Background
Envenoming resulting from snakebites is an important public health problem in many tropical and subtropical countries. Few attempts have been made to quantify the burden, and recent estimates all suffer from the lack of an objective and reproducible methodology. In an attempt to provide an accurate, up-to-date estimate of the scale of the global problem, we developed a new method to estimate the disease burden due to snakebites.
Methods and Findings
The global estimates were based on regional estimates that were, in turn, derived from data available for countries within a defined region. Three main strategies were used to obtain primary data: electronic searching for publications on snakebite, extraction of relevant country-specific mortality data from databases maintained by United Nations organizations, and identification of grey literature by discussion with key informants. Countries were grouped into 21 distinct geographic regions that are as epidemiologically homogenous as possible, in line with the Global Burden of Disease 2005 study (Global Burden Project of the World Bank). Incidence rates for envenoming were extracted from publications and used to estimate the number of envenomings for individual countries; if no data were available for a particular country, the lowest incidence rate within a neighbouring country was used. Where death registration data were reliable, reported deaths from snakebite were used; in other countries, deaths were estimated on the basis of observed mortality rates and the at-risk population. We estimate that, globally, at least 421,000 envenomings and 20,000 deaths occur each year due to snakebite. These figures may be as high as 1,841,000 envenomings and 94,000 deaths. Based on the fact that envenoming occurs in about one in every four snakebites, between 1.2 million and 5.5 million snakebites could occur annually.
Conclusions
Snakebites cause considerable morbidity and mortality worldwide. The highest burden exists in South Asia, Southeast Asia, and sub-Saharan Africa.
Janaka de Silva and colleagues estimate that globally at least 421,000 envenomings and 20,000 deaths occur each year due to snakebite.
Editors' Summary
Background.
Of the 3,000 or so snake species that exist in the world, about 600 are venomous. Venomous snakes—which exist on every continent except Antarctica—immobilize their prey by injecting modified saliva (venom) that contains toxins into their prey's tissues through their fangs—specialized, hollow teeth. Snakes also use their venoms for self defense and will bite people who threaten, startle or provoke them. Snakebites caused by the families Viperidae (for example, pit vipers) and Elapidae (for example, kraits and cobras) are particularly dangerous to people. The potentially fatal effects of being “envenomed” (having venom injected) by these snakes include widespread bleeding, muscle paralysis, and tissue destruction (necrosis) around the bite site. Bites from these snakes can also cause permanent disability. For example, snakebite victims, who tend to be young and male, may have to have a limb amputated because of necrosis. The best treatment for any snakebite is to get the victim to a hospital as soon as possible where antivenoms (mixtures of antibodies that neutralize venoms) can be given.
Why Was This Study Done?
Although snakebites occur throughout the world, envenoming snakebites are thought to pose a particularly important yet largely neglected threat to public health. This is especially true in rural areas of tropical and subtropical countries where snakebites are common but where there is limited access to health care and to antivenoms. The true magnitude of the public-health threat posed by snakebites in these countries (and elsewhere in the world) is unknown, which makes it hard for public-health officials to optimize the prevention and treatment of snakebites in their respective countries. In this study, therefore, the researchers develop and apply a new method to estimate the global burden of snakebite.
What Did the Researchers Do and Find?
The researchers systematically searched the scientific literature for publications on snakebites and deaths from snakebites and extracted data on snakebite deaths in individual countries from the World Health Organization (WHO) mortality database. They also contacted Ministries of Health, National Poison Centers, and snakebite experts for unpublished information (“grey” literature) on snakebites. Together, these three approaches provided data on the number of snakebite envenomings and deaths for 135 and 162 countries, respectively. The researchers then grouped the 227 countries of the world into 21 geographical regions, each of which contained countries with similar population characteristics, and used the results of studies done in individual countries within each region to estimate the numbers of snakebite envenomings and deaths for each region. Finally, they added up these estimates to obtain an estimate of the global burden of snakebite. Using this method, the researchers estimate that, worldwide, at least 421,000 envenomings and 20,000 deaths from snakebite occur every year; the actual numbers, they suggest, could be as high as 1.8 million envenomings and 94,000 deaths. Their estimates also indicate that the highest burden of snakebite envenomings and death occurs in South and Southeast Asia and in sub-Saharan Africa, and that India is the country with the highest annual number of envenomings (81,000) and deaths (nearly 11,000).
What Do These Findings Mean?
These findings indicate that snakebites cause considerable illness and death around the world. Because of the careful methods used by the researchers, their global estimates of snakebite envenomings and deaths are probably more accurate than previous estimates. However, because the researchers had to make many assumptions in their calculations and because there are so few reliable data on the numbers of snakebites and deaths from the rural tropics, the true regional and global numbers of these events may differ substantially from the estimates presented here. In particular, the regional estimates for eastern sub-Saharan Africa, a region where snakebites are very common and where antivenoms are particularly hard to obtain, are likely to be inaccurate because they are based on a single study. The researchers, therefore, call for more studies on snakebite envenoming and deaths to be done to provide the information needed to deal effectively with this neglected public-health problem.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050218.
This study is further discussed in a PLoS Medicine Perspective by Chippaux
The MedlinePlus Medical Encyclopedia has a page on snakebites (in English and Spanish)
The UK National Health Service Direct health encyclopedia has detailed information about all aspects of snakebites
Wikipedia has pages on venomous snakes and on snakebites (note: Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The World Health Organization provides information about antivenoms and about efforts to increase access to antivenoms in developing countries (available in several languages)
A previous article in PLoS Medicine also discusses the neglected problem of snakebite envenoming: Gutiérrez JM, Theakston RDG, Warrell DA (2006) Confronting the Neglected Problem of Snake Bite Envenoming: The Need for a Global Partnership. PLoS Med 3(6): e150
doi:10.1371/journal.pmed.0050218
PMCID: PMC2577696  PMID: 18986210
25.  Natural Ventilation for the Prevention of Airborne Contagion 
PLoS Medicine  2007;4(2):e68.
Background
Institutional transmission of airborne infections such as tuberculosis (TB) is an important public health problem, especially in resource-limited settings where protective measures such as negative-pressure isolation rooms are difficult to implement. Natural ventilation may offer a low-cost alternative. Our objective was to investigate the rates, determinants, and effects of natural ventilation in health care settings.
Methods and Findings
The study was carried out in eight hospitals in Lima, Peru; five were hospitals of “old-fashioned” design built pre-1950, and three of “modern” design, built 1970–1990. In these hospitals 70 naturally ventilated clinical rooms where infectious patients are likely to be encountered were studied. These included respiratory isolation rooms, TB wards, respiratory wards, general medical wards, outpatient consulting rooms, waiting rooms, and emergency departments. These rooms were compared with 12 mechanically ventilated negative-pressure respiratory isolation rooms built post-2000. Ventilation was measured using a carbon dioxide tracer gas technique in 368 experiments. Architectural and environmental variables were measured. For each experiment, infection risk was estimated for TB exposure using the Wells-Riley model of airborne infection. We found that opening windows and doors provided median ventilation of 28 air changes/hour (ACH), more than double that of mechanically ventilated negative-pressure rooms ventilated at the 12 ACH recommended for high-risk areas, and 18 times that with windows and doors closed (p < 0.001). Facilities built more than 50 years ago, characterised by large windows and high ceilings, had greater ventilation than modern naturally ventilated rooms (40 versus 17 ACH; p < 0.001). Even within the lowest quartile of wind speeds, natural ventilation exceeded mechanical (p < 0.001). The Wells-Riley airborne infection model predicted that in mechanically ventilated rooms 39% of susceptible individuals would become infected following 24 h of exposure to untreated TB patients of infectiousness characterised in a well-documented outbreak. This infection rate compared with 33% in modern and 11% in pre-1950 naturally ventilated facilities with windows and doors open.
Conclusions
Opening windows and doors maximises natural ventilation so that the risk of airborne contagion is much lower than with costly, maintenance-requiring mechanical ventilation systems. Old-fashioned clinical areas with high ceilings and large windows provide greatest protection. Natural ventilation costs little and is maintenance free, and is particularly suited to limited-resource settings and tropical climates, where the burden of TB and institutional TB transmission is highest. In settings where respiratory isolation is difficult and climate permits, windows and doors should be opened to reduce the risk of airborne contagion.
In eight hospitals in Lima, opening windows and doors maximised natural ventilation and lowered the risk of airborne infection. Old-fashioned clinical areas with high ceilings and large windows provide greatest protection.
Editors' Summary
Background.
Tuberculosis (TB) is a major cause of ill health and death worldwide, with around one-third of the world's population infected with the bacterium that causes it (Mycobacterium tuberculosis). One person with active tuberculosis can go on to infect many others; the bacterium is passed in tiny liquid droplets that are produced when someone with active disease coughs, sneezes, spits, or speaks. The risk of tuberculosis being transmitted in hospital settings is particularly high, because people with tuberculosis are often in close contact with very many other people. Currently, most guidelines recommend that the risk of transmission be controlled in certain areas where TB is more likely by making sure that the air in rooms is changed with fresh air between six and 12 times an hour. Air changes can be achieved with simple measures such as opening windows and doors, or by installing mechanical equipment that forces air changes and also keeps the air pressure in an isolation room lower than that outside it. Such “negative pressure,” mechanically ventilated systems are often used on tuberculosis wards to prevent air flowing from isolation rooms to other rooms outside, and so to prevent people on the tuberculosis ward from infecting others.
Why Was This Study Done?
In many parts of the world, hospitals do not have equipment even for simple air conditioning, let alone the special equipment needed for forcing high air changes in isolation rooms and wards. Instead they rely on opening windows and doors in order to reduce the transmission of TB, and this is called natural ventilation. However, it is not clear whether these sorts of measures are adequate for controlling TB transmission. It is important to find out what sorts of systems work best at controlling TB in the real world, so that hospitals and wards can be designed appropriately, within available resources.
What Did the Researchers Do and Find?
This study was based in Lima, Peru's capital city. The researchers studied a variety of rooms, including tuberculosis wards and respiratory isolation rooms, in the city's hospitals. Rooms which had only natural measures for encouraging airflow were compared with mechanically ventilated, negative pressure rooms, which were built much more recently. A comparison was also done between rooms in old hospitals that were naturally ventilated with rooms in newer hospitals that were also naturally ventilated. The researchers used a particular method to measure the number of air changes per hour within each room, and based on this they estimated the risk of a person with TB infecting others using a method called the Wells-Riley equation. The results showed that natural ventilation provided surprisingly high rates of air exchange, with an average of 28 air changes per hour. Hospitals over 50 years old, which generally had large windows and high ceilings, had the highest ventilation, with an average of 40 air changes per hour. This rate compared with 17 air changes per hour in naturally ventilated rooms in modern hospitals, which tended to have lower ceilings and smaller windows. The rooms with modern mechanical ventilation were supposed to have 12 air changes per hour but in reality this was not achieved, as the systems were not maintained properly. The Wells-Riley equation predicted that if an untreated person with tuberculosis was exposed to other people, within 24 hours this person would infect 39% of the people in the mechanically ventilated room, 33% of people in the naturally ventilated new hospital rooms, and only 11% of the people in the naturally ventilated old hospital rooms.
What Do These Findings Mean?
These findings suggest that natural methods of encouraging airflow (e.g., opening doors and windows) work well and in theory could reduce the likelihood of TB being carried from one person to another. Some aspects of the design of wards in old hospitals (such as large windows and high ceilings) are also likely to achieve better airflow and reduce the risk of infection. In poor countries, where mechanical ventilation systems might be too expensive to install and maintain properly, rooms that are designed to naturally achieve good airflow might be the best choice. Another advantage of natural ventilation is that it is not restricted by cost to just high-risk areas, and can therefore be used in many different parts of the hospital, including emergency departments, outpatient departments, and waiting rooms, and it is here that many infectious patients are to be found.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040068.
Information from the World Health Organization on tuberculosis, detailing global efforts to prevent the spread of TB
The World Health Organization publishes guidelines for the prevention of TB in health care facilities in resource-limited settings
Tuberculosis infection control in the era of expanding HIV care and treatment is discussed in an addendum to the above booklet
The Centers for Disease Control have published guidelines for preventing the transmission of mycobacterium tuberculosis in health care settings
Wikipedia has an entry on nosocomial infections (diseases that are spread in hospital). Wikipedia is an internet encyclopedia anyone can edit
A PLoS Medicine Perspective by Peter Wilson, “Is Natural Ventilation a Useful Tool to Prevent the Airborne Spread of TB?” discusses the implications of this study
doi:10.1371/journal.pmed.0040068
PMCID: PMC1808096  PMID: 17326709

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