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1.  Anatomy of the Epidemiological Literature on the 2003 SARS Outbreaks in Hong Kong and Toronto: A Time-Stratified Review 
PLoS Medicine  2010;7(5):e1000272.
Weijia Xing and colleagues reviewed the published epidemiological literature on SARS and show that less than a quarter of papers were published during the epidemic itself, suggesting that the research published lagged substantially behind the need for it.
Outbreaks of emerging infectious diseases, especially those of a global nature, require rapid epidemiological analysis and information dissemination. The final products of those activities usually comprise internal memoranda and briefs within public health authorities and original research published in peer-reviewed journals. Using the 2003 severe acute respiratory syndrome (SARS) epidemic as an example, we conducted a comprehensive time-stratified review of the published literature to describe the different types of epidemiological outputs.
Methods and Findings
We identified and analyzed all published articles on the epidemiology of the SARS outbreak in Hong Kong or Toronto. The analysis was stratified by study design, research domain, data collection, and analytical technique. We compared the SARS-case and matched-control non-SARS articles published according to the timeline of submission, acceptance, and publication. The impact factors of the publishing journals were examined according to the time of publication of SARS articles, and the numbers of citations received by SARS-case and matched-control articles submitted during and after the epidemic were compared. Descriptive, analytical, theoretical, and experimental epidemiology concerned, respectively, 54%, 30%, 11%, and 6% of the studies. Only 22% of the studies were submitted, 8% accepted, and 7% published during the epidemic. The submission-to-acceptance and acceptance-to-publication intervals of the SARS articles submitted during the epidemic period were significantly shorter than the corresponding intervals of matched-control non-SARS articles published in the same journal issues (p<0.001 and p<0.01, respectively). The differences of median submission-to-acceptance intervals and median acceptance-to-publication intervals between SARS articles and their corresponding control articles were 106.5 d (95% confidence interval [CI] 55.0–140.1) and 63.5 d (95% CI 18.0–94.1), respectively. The median numbers of citations of the SARS articles submitted during the epidemic and over the 2 y thereafter were 17 (interquartile range [IQR] 8.0–52.0) and 8 (IQR 3.2–21.8), respectively, significantly higher than the median numbers of control article citations (15, IQR 8.5–16.5, p<0.05, and 7, IQR 3.0–12.0, p<0.01, respectively).
A majority of the epidemiological articles on SARS were submitted after the epidemic had ended, although the corresponding studies had relevance to public health authorities during the epidemic. To minimize the lag between research and the exigency of public health practice in the future, researchers should consider adopting common, predefined protocols and ready-to-use instruments to improve timeliness, and thus, relevance, in addition to standardizing comparability across studies. To facilitate information dissemination, journal managers should reengineer their fast-track channels, which should be adapted to the purpose of an emerging outbreak, taking into account the requirement of high standards of quality for scientific journals and competition with other online resources.
Please see later in the article for the Editors' Summary
Editors' Summary
Every now and then, a new infectious disease appears in a human population or an old disease becomes much more common or more geographically widespread. Recently, several such “emerging infectious diseases” have become major public health problems. For example, HIV/AIDS, hepatitis C, and severe acute respiratory syndrome (SARS) have all emerged in the past three decades and spread rapidly round the world. When an outbreak (epidemic) of an emerging infectious disease occurs, epidemiologists (scientists who study the causes, distribution, and control of diseases in populations) swing into action, collecting and analyzing data on the new threat to human health. Epidemiological studies are rapidly launched to identify the causative agent of the new disease, to investigate how the disease spreads, to define diagnostic criteria for the disease, to evaluate potential treatments, and to devise ways to control the disease's spread. Public health officials then use the results of these studies to bring the epidemic under control.
Why Was This Study Done?
Clearly, epidemics of emerging infectious diseases can only be controlled rapidly and effectively if the results of epidemiological studies are made widely available in a timely manner. Public health bulletins (for example, the Morbidity and Mortality Weekly Report from the US Centers from Disease Control and Prevention) are an important way of disseminating information as is the publication of original research in peer-reviewed academic journals. But how timely is this second dissemination route? Submission, peer-review, revision, re-review, acceptance, and publication of a piece of academic research can be a long process, the speed of which is affected by the responses of both authors and journals. In this study, the researchers analyze how the results of academic epidemiological research are submitted and published in journals during and after an emerging infectious disease epidemic using the 2003 SARS epidemic as an example. The first case of SARS was identified in Asia in February 2003 and rapidly spread around the world. 8,098 people became ill with SARS and 774 died before the epidemic was halted in July 2003.
What Did the Researchers Do and Find?
The researchers identified more than 300 journal articles covering epidemiological research into the SARS outbreak in Hong Kong, China, and Toronto, Canada (two cities strongly affected by the epidemic) that were published online or in print between January 1, 2003 and July 31, 2007. The researchers' analysis of these articles shows that more than half them were descriptive epidemiological studies, investigations that focused on describing the distribution of SARS; a third were analytical epidemiological studies that tried to discover the cause of SARS. Overall, 22% of the journal articles were submitted for publication during the epidemic. Only 8% of the articles were accepted for publication and only 7% were actually published during the epidemic. The median (average) submission-to-acceptance and acceptance-to-publication intervals for SARS articles submitted during the epidemic were 55 and 77.5 days, respectively, much shorter intervals than those for non-SARS articles published in the same journal issues. After the epidemic was over, the submission-to-acceptance and acceptance-to-publication intervals for SARS articles was similar to that of non-SARS articles.
What Do These Findings Mean?
These findings show that, although the academic response to the SARS epidemic was rapid, most articles on the epidemiology of SARS were published after the epidemic was over even though SARS was a major threat to public health. Possible reasons for this publication delay include the time taken by authors to prepare and undertake their studies, to write and submit their papers, and, possibly, their tendency to first submit their results to high profile journals. The time then taken by journals to review the studies, make decisions about publication, and complete the publication process might also have delayed matters. To minimize future delays in the publication of epidemiological research on emerging infectious diseases, epidemiologists could adopt common, predefined protocols and ready-to-use instruments, which would improve timeliness and ensure comparability across studies, suggest the researchers. Journals, in turn, could improve their fast-track procedures and could consider setting up online sections that could be activated when an emerging infectious disease outbreak occurred. Finally, journals could consider altering their review system to speed up the publication process provided the quality of the final published articles was not compromised.
Additional Information
Please access these Web sites via the online version of this summary at
The US National Institute of Allergy and Infectious Diseases provides information on emerging infectious diseases
The US Centers for Control and Prevention of Diseases also provides information about emerging infectious diseases, including links to other resources, and information on SARS
Wikipedia has a page on epidemiology (note that Wikipedia is a free online encyclopedia that anyone can edit; available in several languages)
The World Health Organization has information on SARS (in several languages)
PMCID: PMC2864302  PMID: 20454570
2.  The Effects of Influenza Vaccination of Health Care Workers in Nursing Homes: Insights from a Mathematical Model 
PLoS Medicine  2008;5(10):e200.
Annual influenza vaccination of institutional health care workers (HCWs) is advised in most Western countries, but adherence to this recommendation is generally low. Although protective effects of this intervention for nursing home patients have been demonstrated in some clinical trials, the exact relationship between increased vaccine uptake among HCWs and protection of patients remains unknown owing to variations between study designs, settings, intensity of influenza seasons, and failure to control all effect modifiers. Therefore, we use a mathematical model to estimate the effects of HCW vaccination in different scenarios and to identify a herd immunity threshold in a nursing home department.
Methods and Findings
We use a stochastic individual-based model with discrete time intervals to simulate influenza virus transmission in a 30-bed long-term care nursing home department. We simulate different levels of HCW vaccine uptake and study the effect on influenza virus attack rates among patients for different institutional and seasonal scenarios. Our model reveals a robust linear relationship between the number of HCWs vaccinated and the expected number of influenza virus infections among patients. In a realistic scenario, approximately 60% of influenza virus infections among patients can be prevented when the HCW vaccination rate increases from 0 to 1. A threshold for herd immunity is not detected. Due to stochastic variations, the differences in patient attack rates between departments are high and large outbreaks can occur for every level of HCW vaccine uptake.
The absence of herd immunity in nursing homes implies that vaccination of every additional HCW protects an additional fraction of patients. Because of large stochastic variations, results of small-sized clinical trials on the effects of HCW vaccination should be interpreted with great care. Moreover, the large variations in attack rates should be taken into account when designing future studies.
Using a mathematical model to simulate influenza transmission in nursing homes, Carline van den Dool and colleagues find that each additional staff member vaccinated further reduces the risk to patients.
Editors' Summary
Every winter, millions of people catch influenza, a contagious viral disease of the nose, throat, and airways. Most people recover completely from influenza within a week or two but some develop life-threatening complications such as bacterial pneumonia. As a result, influenza outbreaks kill about half a million people—mainly infants, elderly people, and chronically ill individuals—each year. To minimize influenza-related deaths, the World Health Organization recommends that vulnerable people be vaccinated against influenza every autumn. Annual vaccination is necessary because flu viruses continually make small changes to the viral proteins (antigens) that the immune system recognizes. This means that an immune response produced one year provides only partial protection against influenza the next year. To provide maximum protection against influenza, each year's vaccine contains disabled versions of the major circulating strains of influenza viruses.
Why Was This Study Done?
Most Western countries also recommend annual flu vaccination for health care workers (HCWs) in hospitals and other institutions to reduce the transmission of influenza to vulnerable patients. However, many HCWs don't get a regular flu shot, so should efforts be made to increase their rate of vaccine uptake? To answer this question, public-health experts need to know more about the relationship between vaccine uptake among HCWs and patient protection. In particular, they need to know whether a high rate of vaccine uptake by HCWs will provide “herd immunity.” Herd immunity occurs because, when a sufficient fraction of a population is immune to a disease that passes from person to person, infected people rarely come into contact with susceptible people, which means that both vaccinated and unvaccinated people are protected from the disease. In this study, the researchers develop a mathematical model to investigate the relationship between vaccine uptake among HCWs and patient protection in a nursing home department.
What Did the Researchers Do and Find?
To predict influenza virus attack rates (the number of patient infections divided by the number of patients in a nursing home department during an influenza season) at different levels of HCW vaccine uptake, the researchers develop a stochastic transmission model to simulate epidemics on a computer. This model predicts that as the HCW vaccination rate increases from 0 (no HCWs vaccinated) to 1 (all the HCWs vaccinated), the expected average influenza virus attack rate decreases at a constant rate. In the researchers' baseline scenario—a nursing home department with 30 beds where patients come into contact with other patients, HCWs, and visitors—the model predicts that about 60% of the patients who would have been infected if no HCWs had been vaccinated are protected when all the HCWs are vaccinated, and that seven HCWs would have to be vaccinated to protect one patient. This last figure does not change with increasing vaccine uptake, which indicates that there is no level of HCW vaccination that completely stops the spread of influenza among the patients; that is, there is no herd immunity. Finally, the researchers show that large influenza outbreaks can happen by chance at every level of HCW vaccine uptake.
What Do These Findings Mean?
As with all mathematical models, the accuracy of these predictions may depend on the specific assumptions built into the model. Therefore the researchers verified that their findings hold for a wide range of plausible assumptions. These findings have two important practical implications. First, the direct relationship between HCW vaccination and patient protection and the lack of any herd immunity suggest that any increase in HCW vaccine uptake will be beneficial to patients in nursing homes. That is, increasing the HCW vaccination rate from 80% to 90% is likely to be as important as increasing it from 10% to 20%. Second, even 100% HCW vaccination cannot guarantee that influenza outbreaks will not occasionally occur in nursing homes. Because of the large variation in attack rates, the results of small clinical trials on the effects of HCW vaccination may be inaccurate and future studies will need to be very large if they are to provide reliable estimates of the amount of protection that HCW vaccination provides to vulnerable patients.
Additional Information.
Please access these Web sites via the online version of this summary at
Read the related PLoSMedicine Perspective by Cécile Viboud and Mark Miller
A related PLoSMedicine Research Article by Jeffrey Kwong and colleagues is also available
The World Health Organization provides information on influenza and on influenza vaccines (in several languages)
The US Centers for Disease Control and Prevention provide information for patients and professionals on all aspects of influenza (in English and Spanish)
The UK Health Protection Agency also provides information on influenza
MedlinePlus provides a list of links to other information about influenza (in English and Spanish)
The UK National Health Service provides information about herd immunity, including a simple explanatory animation
The European Centre for Disease Prevention and Control provides an overview on the types of influenza
PMCID: PMC2573905  PMID: 18959470
3.  The experience of the 2003 SARS outbreak as a traumatic stress among frontline healthcare workers in Toronto: lessons learned. 
The outbreak of severe acute respiratory syndrome (SARS) in the first half of 2003 in Canada was unprecedented in several respects. Understanding the psychological impact of the outbreak on healthcare workers, especially those in hospitals, is important in planning for future outbreaks of emerging infectious diseases. This review draws upon qualitative and quantitative studies of the SARS outbreak in Toronto to outline the factors that contributed to healthcare workers' experiencing the outbreak as a psychological trauma. Overall, it is estimated that a high degree of distress was experienced by 29-35% of hospital workers. Three categories of contributory factors were identified. Relevant contextual factors were being a nurse, having contact with SARS patients and having children. Contributing attitudinal factors and processes were experiencing job stress, perceiving stigmatization, coping by avoiding crowds and colleagues, and feeling scrutinized. Pre-existing trait factors also contributed to vulnerability. Lessons learned from the outbreak include: (i) that effort is required to mitigate the psychological impact of infection control procedures, especially the interpersonal isolation that these procedures promote; (ii) that effective risk communication is a priority early in an outbreak; (iii) that healthcare workers may have a role in influencing patterns of media coverage that increase or decrease morale; (iv) that healthcare workers benefit from resources that facilitate reflection on the effects of extraordinary stressors; and (v) that healthcare workers benefit from practical interventions that demonstrate tangible support from institutions.
PMCID: PMC1693388  PMID: 15306398
4.  Risk Factors for SARS Transmission from Patients Requiring Intubation: A Multicentre Investigation in Toronto, Canada 
PLoS ONE  2010;5(5):e10717.
In the 2003 Toronto SARS outbreak, SARS-CoV was transmitted in hospitals despite adherence to infection control procedures. Considerable controversy resulted regarding which procedures and behaviours were associated with the greatest risk of SARS-CoV transmission.
A retrospective cohort study was conducted to identify risk factors for transmission of SARS-CoV during intubation from laboratory confirmed SARS patients to HCWs involved in their care. All SARS patients requiring intubation during the Toronto outbreak were identified. All HCWs who provided care to intubated SARS patients during treatment or transportation and who entered a patient room or had direct patient contact from 24 hours before to 4 hours after intubation were eligible for this study. Data was collected on patients by chart review and on HCWs by interviewer-administered questionnaire. Generalized estimating equation (GEE) logistic regression models and classification and regression trees (CART) were used to identify risk factors for SARS transmission.
45 laboratory-confirmed intubated SARS patients were identified. Of the 697 HCWs involved in their care, 624 (90%) participated in the study. SARS-CoV was transmitted to 26 HCWs from 7 patients; 21 HCWs were infected by 3 patients. In multivariate GEE logistic regression models, presence in the room during fiberoptic intubation (OR = 2.79, p = .004) or ECG (OR = 3.52, p = .002), unprotected eye contact with secretions (OR = 7.34, p = .001), patient APACHE II score ≥20 (OR = 17.05, p = .009) and patient Pa02/Fi02 ratio ≤59 (OR = 8.65, p = .001) were associated with increased risk of transmission of SARS-CoV. In CART analyses, the four covariates which explained the greatest amount of variation in SARS-CoV transmission were covariates representing individual patients.
Close contact with the airway of severely ill patients and failure of infection control practices to prevent exposure to respiratory secretions were associated with transmission of SARS-CoV. Rates of transmission of SARS-CoV varied widely among patients.
PMCID: PMC2873403  PMID: 20502660
5.  The immediate psychological and occupational impact of the 2003 SARS outbreak in a teaching hospital 
The outbreak of severe acute respiratory syndrome (SARS) in Toronto, which began on Mar. 7, 2003, resulted in extraordinary public health and infection control measures. We aimed to describe the psychological and occupational impact of this event within a large hospital in the first 4 weeks of the outbreak and the subsequent administrative and mental health response.
Two principal authors met with core team members and mental health care providers at Mount Sinai Hospital, Toronto, to compile retrospectively descriptions of the experiences of staff and patients based on informal observation. All authors reviewed and analyzed the descriptions in an iterative process between Apr. 3 and Apr. 13, 2003.
In a 4-week period, 19 individuals developed SARS, including 11 health care workers. The hospital's response included establishing a leadership command team and a SARS isolation unit, implementing mental health support interventions for patients and staff, overcoming problems with logistics and communication, and overcoming resistance to directives. Patients with SARS reported fear, loneliness, boredom and anger, and they worried about the effects of quarantine and contagion on family members and friends. They experienced anxiety about fever and the effects of insomnia. Staff were adversely affected by fear of contagion and of infecting family, friends and colleagues. Caring for health care workers as patients and colleagues was emotionally difficult. Uncertainty and stigmatization were prominent themes for both staff and patients.
The hospital's response required clear communication, sensitivity to individual responses to stress, collaboration between disciplines, authoritative leadership and provision of relevant support. The emotional and behavioural reactions of patients and staff are understood to be a normal, adaptive response to stress in the face of an overwhelming event.
PMCID: PMC154178  PMID: 12743065
6.  The psychological effect of severe acute respiratory syndrome on emergency department staff 
The severe acute respiratory syndrome (SARS) outbreak in 2003 affected 29 countries. The SARS outbreak was unique in its rapid transmission and it resulted in heavy stress in first‐line healthcare workers, particularly in the emergency department.
: To determine the influence of SARS on the psychological status, including post‐traumatic stress disorder (PTSD) symptoms, of the staff in the emergency department.
To investigate whether different working conditions in the hospital led to different psychological effects on healthcare workers, the psychological effect on emergency department staff in the high‐risk ward was compared with that on psychiatric ward staff in the medium‐risk ward. Davidson Trauma Scale‐Chinese version (DTS‐C) and Chinese Health Questionnaire‐12 (CHQ‐12) items were designed to check the psychological status of the staff in the month after the end of the SARS outbreak.
86 of 92 (93.5%) medical staff considered the SARS outbreak to be a traumatic experience. The DTS‐C scores of staff in the emergency department and in the psychiatric ward were significantly different (p = 0.04). No significant difference in CHQ score was observed between the two groups. Emergency department staff had more severe PTSD symptoms than staff in the psychiatric ward.
SARS was a traumatic experience for healthcare providers in Taiwan. Most staff in the emergency department and in the psychiatric ward had PTSD. Emergency department staff had more severe PTSD symptoms than staff in the psychiatric ward.
PMCID: PMC2658141  PMID: 17183035
7.  The Psychological Impact of the SARS Epidemic on Hospital Employees in China: Exposure, Risk Perception, and Altruistic Acceptance of Risk 
We examined the psychological impact of the 2003 outbreak of severe acute respiratory syndrome (SARS) on hospital employees in Beijing, China.
In 2006, randomly selected employees (n = 549) of a hospital in Beijing were surveyed concerning their exposure to the 2003 SARS outbreak, and the ways in which the outbreak had affected their mental health.
About 10% of the respondents had experienced high levels of posttraumatic stress (PTS) symptoms since the SARS outbreak. Respondents who had been quarantined, or worked in high-risk locations such as SARS wards, or had friends or close relatives who contracted SARS, were 2 to 3 times more likely to have high PTS symptom levels, than those without these exposures. Respondents’ perceptions of SARS-related risks were significantly positively associated with PTS symptom levels and partially mediated the effects of exposure. Altruistic acceptance of work-related risks was negatively related to PTS levels.
The psychological impact of stressful events related to an infectious disease outbreak may be mediated by peoples’ perceptions of those events; altruism may help to protect some health care workers against these negative impacts.
PMCID: PMC3780353  PMID: 19497162
severe acute respiratory syndrome; health care workers; posttraumatic stress; infectious disease outbreak; China
8.  Appropriate use of personal protective equipment among healthcare workers in public sector hospitals and primary healthcare polyclinics during the SARS outbreak in Singapore 
Chia, S | Koh, D | Fones, C | Qian, F | Ng, V | Tan, B | Wong, K | Chew, W | Tang, H | Ng, W | Muttakin, Z | Emmanuel, S | Fong, N | Koh, G | Lim, M
Background: Singapore was affected by an outbreak of severe acute respiratory syndrome (SARS) from 25 February to 31 May 2003, with 238 probable cases and 33 deaths.
Aims: To study usage of personal protective equipment (PPE) among three groups of healthcare workers (HCWs: doctors, nurses, and administrative staff), to determine if the appropriate PPE were used by the different groups and to examine the factors that may determine inappropriate use.
Methods: A self-administered questionnaire survey of 14 554 HCWs in nine healthcare settings, which included tertiary care hospitals, community hospitals, and polyclinics, was carried out in May–July 2003. Only doctors, nurses, and clerical staff were selected for subsequent analysis.
Results: A total of 10 236 valid questionnaires were returned (70.3% response); 873 doctors, 4404 nurses, and 921 clerical staff were studied. A total of 32.5% of doctors, 48.7% of nurses, and 77.1% of the administrative staff agreed that paper and/or surgical masks were "useful in protecting from contracting SARS". Among this group, 23.6% of doctors and 42.3% of nurses reported working with SARS patients. The view that a paper and/or surgical mask was adequate protection against SARS was held by 33.3% of doctors and 55.9% of nurses working at the A&E unit, 30.5% of doctors and 49.4% of nurses from medical wards, and 27.5% of doctors and 37.1% of nurses from intensive care units. Factors which predicted for agreement that paper and/or surgical masks were protective against SARS, included HCW's job title, reported contact with SARS patients, area of work, and Impact Events Scale scores.
Conclusion: A variety of factors determine appropriate use of personal protective equipment by HCWs in the face of a major SARS outbreak.
PMCID: PMC1741057  PMID: 15961624
9.  Prevalence of Psychiatric Disorders Among Toronto Hospital Workers One to Two Years After the SARS Outbreak 
This study aimed to determine the incidence of psychiatric disorders among health care workers in Toronto in the one- to two-year period after the 2003 outbreak of severe acute respiratory syndrome (SARS) and to test predicted risk factors.
New-onset episodes of psychiatric disorders were assessed among 139 health care workers by using the Structured Clinical Interview for DSM-IV and the Clinician-Administered PTSD Scale. Past history of psychiatric illness, years of health care experience, and the perception of adequate training and support were tested as predictors of the incidence of new-onset episodes psychiatric disorders after the SARS outbreak.
The lifetime prevalence of any depressive, anxiety, or substance use diagnosis was 30%. Only one health care worker who identified the SARS experience as a traumatic event was diagnosed as having PTSD. New episodes of psychiatric disorders occurred among seven health care workers (5%). New episodes of psychiatric disorders were directly associated with a history of having a psychiatric disorder before the SARS outbreak (p=.02) and inversely associated with years of health care experience (p=.03) and the perceived adequacy of training and support (p=.03).
Incidence of new episodes of psychiatric disorders after the SARS outbreak were similar to or lower than community incidence rates, which may indicate the resilience of health care workers who continued to work in hospitals one to two years after the SARS outbreak. In preparation for future events, such as pandemic influenza, training and support may bolster the resilience of health care workers who are at higher risk by virtue of their psychiatric history and fewer years of health care experience.
PMCID: PMC2923654  PMID: 18182545 CAMSID: cams1445
10.  Population mortality during the outbreak of Severe Acute Respiratory Syndrome in Toronto 
BMC Public Health  2007;7:93.
Extraordinary infection control measures limited access to medical care in the Greater Toronto Area during the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak. The objective of this study was to determine if the period of these infection control measures was associated with changes in overall population mortality due to causes other than SARS.
Observational study of death registry data, using Poisson regression and interrupted time-series analysis to examine all-cause mortality rates (excluding deaths due to SARS) before, during, and after the SARS outbreak. The population of Ontario was grouped into the Greater Toronto Area (N = 2.9 million) and the rest of Ontario (N = 9.3 million) based upon the level of restrictions on delivery of clinical services during the SARS outbreak.
There was no significant change in mortality in the Greater Toronto Area before, during, and after the period of the SARS outbreak in 2003 compared to the corresponding time periods in 2002 and 2001. The rate ratio for all-cause mortality during the SARS outbreak was 0.99 [95% Confidence Interval (CI) 0.93–1.06] compared to 2002 and 0.96 [95% CI 0.90–1.03] compared to 2001. An interrupted time series analysis found no significant change in mortality rates in the Greater Toronto Area associated with the period of the SARS outbreak.
Limitations on access to medical services during the 2003 SARS outbreak in Toronto had no observable impact on short-term population mortality. Effects on morbidity and long-term mortality were not assessed. Efforts to contain future infectious disease outbreaks due to influenza or other agents must consider effects on access to essential health care services.
PMCID: PMC1894965  PMID: 17535440
11.  Using simulation for training and to change protocol during the outbreak of severe acute respiratory syndrome 
Critical Care  2005;10(1):R3.
During the 2003 severe acute respiratory syndrome (SARS) crisis, we proposed and tested a new protocol for cardiac arrest in a patient with SARS. The protocol was rapidly and effectively instituted by teamwork training using high-fidelity simulation.
Phase 1 was a curriculum design of a SARS-specific cardiac arrest protocol in three steps: planning the new protocol, repeated simulations of this protocol in a classroom, and a subsequent simulation of a cardiac arrest on a hospital ward. Phase 2 was the training of 275 healthcare workers (HCWs) using the new protocol. Training involved a seminar, practice in wearing the mandatory personal protection system (PPS), and cardiac arrest simulations with subsequent debriefing.
Simulation provided insights that had not been considered in earlier phases of development. For example, a single person can don a PPS worn for the SARS patient in 1 1/2 minutes. However, when multiple members of a cardiac arrest team were dressing simultaneously, the time to don the PPS increased to between 3 1/2 and 5 1/2 minutes. Errors in infection control as well as in medical management of advanced cardiac life support (ACLS) were corrected.
During the SARS crisis, real-time use of a high-fidelity simulator allowed the training of 275 HCWs in 2 weeks, with debriefing and error management. HCWs were required to manage the SARS cardiac arrest wearing unfamiliar equipment and following a modified ACLS protocol. The insight gained from this experience will be valuable for future infectious disease challenges in critical care.
PMCID: PMC1550819  PMID: 16356209
12.  Vaccine Efficacy in Senescent Mice Challenged with Recombinant SARS-CoV Bearing Epidemic and Zoonotic Spike Variants  
PLoS Medicine  2006;3(12):e525.
In 2003, severe acute respiratory syndrome coronavirus (SARS-CoV) was identified as the etiological agent of severe acute respiratory syndrome, a disease characterized by severe pneumonia that sometimes results in death. SARS-CoV is a zoonotic virus that crossed the species barrier, most likely originating from bats or from other species including civets, raccoon dogs, domestic cats, swine, and rodents. A SARS-CoV vaccine should confer long-term protection, especially in vulnerable senescent populations, against both the 2003 epidemic strains and zoonotic strains that may yet emerge from animal reservoirs. We report the comprehensive investigation of SARS vaccine efficacy in young and senescent mice following homologous and heterologous challenge.
Methods and Findings
Using Venezuelan equine encephalitis virus replicon particles (VRP) expressing the 2003 epidemic Urbani SARS-CoV strain spike (S) glycoprotein (VRP-S) or the nucleocapsid (N) protein from the same strain (VRP-N), we demonstrate that VRP-S, but not VRP-N vaccines provide complete short- and long-term protection against homologous strain challenge in young and senescent mice. To test VRP vaccine efficacy against a heterologous SARS-CoV, we used phylogenetic analyses, synthetic biology, and reverse genetics to construct a chimeric virus (icGDO3-S) encoding a synthetic S glycoprotein gene of the most genetically divergent human strain, GDO3, which clusters among the zoonotic SARS-CoV. icGD03-S replicated efficiently in human airway epithelial cells and in the lungs of young and senescent mice, and was highly resistant to neutralization with antisera directed against the Urbani strain. Although VRP-S vaccines provided complete short-term protection against heterologous icGD03-S challenge in young mice, only limited protection was seen in vaccinated senescent animals. VRP-N vaccines not only failed to protect from homologous or heterologous challenge, but resulted in enhanced immunopathology with eosinophilic infiltrates within the lungs of SARS-CoV–challenged mice. VRP-N–induced pathology presented at day 4, peaked around day 7, and persisted through day 14, and was likely mediated by cellular immune responses.
This study identifies gaps and challenges in vaccine design for controlling future SARS-CoV zoonosis, especially in vulnerable elderly populations. The availability of a SARS-CoV virus bearing heterologous S glycoproteins provides a robust challenge inoculum for evaluating vaccine efficacy against zoonotic strains, the most likely source of future outbreaks.
Experiments in mice suggest challenges in vaccine design for controlling future SARS-CoV zoonosis, especially in vulnerable elderly populations.
Editors' Summary
Severe acute respiratory syndrome (SARS) is a flu-like illness and was first recognized in China in 2002, after which the disease rapidly spread around the world. SARS was associated with high death rates, much higher than those for flu. Around 10% of people recognized as being infected with SARS died, and the death rate approached 50% among elderly people. The virus causing SARS was identified as a member of the coronavirus family; it is generally thought that this virus “jumped” to humans from bats, which harbor related viruses. Although SARS was declared eradicated by the World Health Organization in May 2005, there is still the possibility that similar viruses will again cross the species barrier and infect humans, with potentially serious consequences. As a result, many groups are working to develop vaccines that will protect against SARS infection.
Why Was This Study Done?
A SARS vaccine should be effective in people of all ages, including the elderly who are more likely to get seriously ill or die if they become infected. In addition, potential vaccines should protect against different variants of the virus, because there are different types of the virus that could potentially cross the species barrier from animals to humans. Of the different proteins that make up the SARS coronavirus, the spike glycoprotein is thought to elicit an immune response in humans that can protect against future infection. The researchers therefore examined vaccine candidates based on this particular protein (termed SARS-CoV S), as well as a second one called SARS-CoV N, in mice. Specifically, they tested whether the vaccines would protect against SARS infection in both young and older mice, and whether they would protect against infection by different strains of the SARS virus.
What Did the Researchers Do and Find?
The researchers created vaccines based on SARS-CoV S and SARS-CoV N by taking the genes coding for those proteins and inserting them into another type of virus particle that acted as a delivery vehicle. They injected mice with these vaccines and then tested whether the mice generated an immune response against the specific SARS proteins, which they did. The next step was to work out whether mice injected with the vaccines would be protected against later infection with SARS-CoV. The researchers found that mice injected with vaccine based on SARS-CoV S were protected against later infection with a standard SARS-CoV strain, both in the short term (eight weeks after vaccination) and the long term (54 weeks after vaccination). However, the vaccine based on SARS-CoV N did not seem to result in protection, and, worryingly, caused pathological changes in the lungs of mice following virus challenge. To find out if their candidate vaccines would protect against different strains of SARS, the researchers made a synthetic test virus that contained a mixture of genetic material from different natural variants of the virus. This test virus was used to “challenge” mice that had been immunized with the two different vaccines. The researchers found that the vaccine based on SARS-CoV S protected against infection by the test virus when mice were vaccinated young, but it failed to efficiently protect when administered to older mice.
What Do These Findings Mean?
The findings confirm others suggesting that vaccines based on the SARS-CoV S protein are more effective than those based on SARS-CoV N. They also suggest that the former can provide long-term protection in animals vaccinated young against closely related viruses. However, protection against more distantly related viruses remains a challenge, especially when vaccinating older animals. The differences seen between young and older mice suggest that older mice might provide a useful model for animal testing of candidate vaccines for diseases like SARS, flu, and West Nile virus that pose a particular threat to elderly people. Overall, these results provide useful lessons toward future SARS vaccine development in animals. The synthetic virus strain generated here, and others like it, are likely to be useful tools for such future studies.
Additional Information.
Please access these Web sites via the online version of this summary at
• The World Health Organization provides guidance, archives, and other information resources on SARS
• Information from the US Centers for Disease Control on SARS
• Wikipedia (an internet encyclopedia anyone can edit) has an entry on SARS
• Collected resources from MedLinePlus about SARS
PMCID: PMC1716185  PMID: 17194199
13.  Chronic widespread musculoskeletal pain, fatigue, depression and disordered sleep in chronic post-SARS syndrome; a case-controlled study 
BMC Neurology  2011;11:37.
The long term adverse effects of Severe Acute Respiratory Syndrome (SARS), a viral disease, are poorly understood.
Sleep physiology, somatic and mood symptoms of 22 Toronto subjects, 21 of whom were healthcare workers, (19 females, 3 males, mean age 46.29 yrs.+/- 11.02) who remained unable to return to their former occupation (mean 19.8 months, range: 13 to 36 months following SARS) were compared to 7 healthy female subjects. Because of their clinical similarities to patients with fibromyalgia syndrome (FMS) these post-SARS subjects were similarly compared to 21 drug free female patients, (mean age 42.4 +/- 11.8 yrs.) who fulfilled criteria for fibromyalgia.
Chronic post-SARS is characterized by persistent fatigue, diffuse myalgia, weakness, depression, and nonrestorative sleep with associated REM-related apneas/hypopneas, an elevated sleep EEG cyclical alternating pattern, and alpha EEG sleep anomaly. Post- SARS patients had symptoms of pre and post-sleep fatigue and post sleep sleepiness that were similar to the symptoms of patients with FMS, and similar to symptoms of patients with chronic fatigue syndrome. Both post-SARS and FMS groups had sleep instability as indicated by the high sleep EEG cyclical alternating pattern rate. The post-SARS group had a lower rating of the alpha EEG sleep anomaly as compared to the FMS patients. The post-SARS group also reported less pre-sleep and post-sleep musculoskeletal pain symptoms.
The clinical and sleep features of chronic post-SARS form a syndrome of chronic fatigue, pain, weakness, depression and sleep disturbance, which overlaps with the clinical and sleep features of FMS and chronic fatigue syndrome.
PMCID: PMC3071317  PMID: 21435231
14.  Which preventive measures might protect health care workers from SARS? 
BMC Public Health  2009;9:81.
Despite the use of a series of preventive measures, a high incidence of severe acute respiratory syndrome (SARS) was observed among health care workers (HCWs) during the SARS epidemic. This study aimed to determine which preventive measures may have been effective in protecting HCWs from infection, and which were not effective.
A retrospective study was performed among 758 'frontline' health care workers who cared for SARS patients at the Second Affiliated Hospital and the Third Affiliated Hospital of Sun Yat-sen University. The HCWs with IgG against SARS and those without IgG against SARS were respectively defined as the "case group" and the "control group", and logistic regression was conducted to explore the risk factors for SARS infection in HCWs.
After adjusting for age, gender, marital status, educational level, professional title, and the department in which an individual worked, the results of a multivariate logistic regression analysis indicated that incidence of SARS among HCWs was significantly and positively associated with: performing tracheal intubations for SARS patients, methods used for air ventilation in wards, avoiding face-to-face interaction with SARS patients, the number of pairs of gloves worn by HCWs, and caring for serious SARS cases.
Some measures, particularly good air ventilation in SARS wards, may be effective in minimizing or preventing SARS transmission among HCWs in hospitals.
PMCID: PMC2666722  PMID: 19284644
15.  A Surveillance System to Reduce Transmission of Pandemic H1N1 (2009) Influenza in a 2600-Bed Medical Center 
PLoS ONE  2012;7(3):e32731.
Concerns have been raised about how the transmission of emerging infectious diseases from patients to healthcare workers (HCWs) and vice versa could be recognized and prevented in a timely manner. An effective strategy to block transmission of pandemic H1N1 (2009) influenza in HCWs is important.
Methodology/Principal Findings
An infection control program was implemented to survey and prevent nosocomial outbreaks of H1N1 (2009) influenza at a 2,600-bed, tertiary-care academic hospital. In total, 4,963 employees at Kaohsiung Chang Gung Memorial Hospital recorded their temperature and received online education on control practices for influenza infections. Administration records provided vaccination records and occupational characteristics of all HCWs. Early recognition of a pandemic H1N1 (2009) influenza case was followed by a semi-structured questionnaire to analyze possible routes of patient contact, household contact, or unspecified contact. Surveillance spanned August 1, 2009 to January 31, 2010; 51 HCWs were confirmed to have novel H1N1 (2009) influenza by quantitative real-time reverse transcription polymerase chain reaction. Prevalence of patient contact, household contact, or unspecified contact infection was 13.7% (7/51), 13.7% (7/51), and 72.5% (37/51), respectively. The prevalence of the novel H1N1 infection was significantly lower among vaccinated HCWs than among unvaccinated HCWs (p<0.001). Higher viral loads in throat swabs were found in HCWs with patient and household contact infection than in those with unspecified contact infection (4.15 vs. 3.53 copies/mL, log10, p = 0.035).
A surveillance system with daily temperature recordings and online education for HCWs is important for a low attack rate of H1N1 (2009) influenza transmission before H1N1 (2009) influenza vaccination is available, and the attack rate is further decreased after mass vaccination. Unspecified contact infection rates were significantly higher than that of patient contact and household contact infection, highlighting the need for public education of influenza transmission in addition to hospital infection control.
PMCID: PMC3302803  PMID: 22427871
Shortages of health care workers (HCWs) represents a serious challenge to ensuring effective HIV care in resource-limited settings (RLS). Stress, motivation, and job satisfaction have been linked with HCW retention and are important in addressing HCW shortages. In this cross-sectional study HCW stress, motivation, and perceived ability to meet patient needs were assessed in PEPFAR-supported urban HIV care and treatment clinics (CTCs) in Tanzania.
A self-administered questionnaire measuring motivation, stress, and perceived ability to meet patient needs was given to HCWs at 16 CTCs. Scales measuring HCW satisfaction, motivation, and stress were developed using principle components analysis. Hierarchical linear models were used to explore the association of HCW and site characteristics with reported satisfaction, stress, motivation, and ability to meet patient needs.
Seventy-three percent (279) of HCWs completed the questionnaire. Most (73%) HCWs reported minimal/no work-related stress, with 48% reporting good/excellent motivation, but 41% also reporting feeling emotionally drained. Almost all (98%) reported feeling able to help their patients, with 68% reporting work as rewarding. Most reported receipt of training and supervision, with good availability of resources. In the multivariate model, direct clinical providers reported lower motivation than management (p<0.05) and HCWs at medium-sized sites reported higher motivation than HCWs at larger sites (p<0.05). HCWs at small and medium sites were more likely to feel able to help patients than those from larger sites (p<0.05 and p<0.001 respectively).
Despite significant patient loads, HCWs in these PEPFAR-supported CTCs reported high levels of motivation, job satisfaction, ability to meet patient needs, low levels of stress but significant emotional toll. Understanding the relationship between support systems such as strong supervision and training and these outcomes is critical in designing interventions to improve motivation, reduce stress and increase retention of HCWs.
PMCID: PMC3580277  PMID: 22066277
HIV; motivation; stress; health care workers; resource limited settings
17.  Men who have sex with men sensitivity training reduces homoprejudice and increases knowledge among Kenyan healthcare providers in coastal Kenya 
Journal of the International AIDS Society  2013;16(4Suppl 3):18748.
Healthcare workers (HCWs) in Africa typically receive little or no training in the healthcare needs of men who have sex with men (MSM), limiting the effectiveness and reach of population-based HIV control measures among this group. We assessed the effect of a web-based, self-directed sensitivity training on MSM for HCWs (, combined with facilitated group discussions on knowledge and homophobic attitudes among HCWs in four districts of coastal Kenya.
We trained four district “AIDS coordinators” to provide a two-day training to local HCWs working at antiretroviral therapy-providing facilities in coastal Kenya. Self-directed learning supported by group discussions focused on MSM sexual risk practices, HIV prevention and healthcare needs. Knowledge was assessed prior to training, immediately after training and three months after training. The Homophobia Scale assessed homophobic attitudes and was measured before and three months after training.
Seventy-four HCWs (68% female; 74% clinical officers or nurses; 84% working in government facilities) from 49 health facilities were trained, of whom 71 (96%) completed all measures. At baseline, few HCWs reported any prior training on MSM anal sexual practices, and most HCWs had limited knowledge of MSM sexual health needs. Homophobic attitudes were most pronounced among HCWs who were male, under 30 years of age, and working in clinical roles or government facilities. Three months after training, more HCWs had adequate knowledge compared to baseline (49% vs. 13%, McNemar's test p<0.001); this was most pronounced in those with clinical or administrative roles and in those from governmental health providers. Compared to baseline, homophobic attitudes had decreased significantly three months after training, particularly among HCWs with high homophobia scores at baseline, and there was some evidence of correlation between improvements in knowledge and reduction in homophobic sentiment.
Scaling up MSM sensitivity training for African HCWs is likely to be a timely, effective and practical means to improve relevant sexual health knowledge and reduce personal homophobic sentiment among HCWs involved in HIV prevention, testing and care in sub-Saharan Africa.
PMCID: PMC3852129  PMID: 24321111
sensitivity training; MSM behaviour; Homophobia Scale; homoprejudice; healthcare workers; Kenya
18.  General hospital staff worries, perceived sufficiency of information and associated psychological distress during the A/H1N1 influenza pandemic 
BMC Infectious Diseases  2010;10:322.
Health care workers (HCWs) presented frequent concerns regarding their health and their families' health and high levels of psychological distress during previous disease outbreaks, such as the SARS outbreak, which was associated with social isolation and intentional absenteeism. We aimed to assess HCWs concerns and anxiety, perceived sufficiency of information, and intended behavior during the recent A/H1N1 influenza pandemic and their associations with psychological distress.
Between September 1st and 30th, 2009, 469 health-care workers (HCWs) of a tertiary teaching hospital completed a 20-item questionnaire regarding concerns and worries about the new A/H1N1 influenza pandemic, along with Cassileth's Information Styles Questionnaire (part-I) and the GHQ-28.
More than half of the present study's HCWs (56.7%) reported they were worried about the A/H1N1 influenza pandemic, their degree of anxiety being moderately high (median 6/9). The most frequent concern was infection of family and friends and the health consequences of the disease (54.9%). The perceived risk of being infected was considered moderately high (median 6/9). Few HCWs (6.6%) had restricted their social contacts and fewer (3.8%) felt isolated by their family members and friends because of their hospital work, while a low percentage (4.3%) indented to take a leave to avoid infection. However, worry and degree of worry were significantly associated with intended absenteeism (p < 0.0005), restriction of social contacts (p < 0.0005), and psychological distress (p = 0.036). Perceived sufficiency of information about several aspects of the A/H1N1 influenza was moderately high, and the overall information about the A/H1N1 influenza was considered clear (median 7.4/9). Also, perceived sufficiency of information for the prognosis of the infection was significantly independently associated with the degree of worry about the pandemic (p = 0.008).
A significant proportion of HCWs experienced moderately high anxiety about the pandemic, and their degree of worry was an independent correlate of psychological distress. Since perceived sufficiency of information about the A/H1N1 influenza prognosis was associated with reduced degree of worry, hospital managers and consultation-liaison psychiatry services should try to provide for HCWs' need for information, in order to offer favourable working conditions in times of extreme distress, such as the current and future pandemics.
PMCID: PMC2990753  PMID: 21062471
19.  Curtailing transmission of severe acute respiratory syndrome within a community and its hospital. 
Severe acute respiratory syndrome (SARS) has been transmitted extensively within hospitals, and healthcare workers (HCWs) have comprised a large proportion of SARS cases worldwide. We present a stochastic model of a SARS outbreak in a community and its hospital. For a range of basic reproductive numbers (R(0)) corresponding to conditions in different cities (but with emphasis on R(0) approximately 3 as reported for Hong Kong and Singapore), we evaluate contact precautions and case management (quarantine and isolation) as containment measures. Hospital-based contact precautions emerge as the most potent measures, with hospital-wide measures being particularly important if screening of HCWs is inadequate. For R(0) = 3, case isolation alone can control a SARS outbreak only if isolation reduces transmission by at least a factor of four and the mean symptom-onset-to-isolation time is less than 3 days. Delays of a few days in contact tracing and case identification severely degrade the utility of quarantine and isolation, particularly in high-transmission settings. Still more detrimental are delays between the onset of an outbreak and the implementation of control measures; for given control scenarios, our model identifies windows of opportunity beyond which the efficacy of containment efforts is reduced greatly. By considering pathways of transmission in our system, we show that if hospital-based transmission is not halted, measures that reduce community-HCW contact are vital to preventing a widespread epidemic. The implications of our results for future emerging pathogens are discussed.
PMCID: PMC1691475  PMID: 14561285
20.  SARS Control and Psychological Effects of Quarantine, Toronto, Canada 
Emerging Infectious Diseases  2004;10(7):1206-1212.
Explores effects of quarantine on those quarantined for SARS, Toronto, Canada
As a transmissible infectious disease, severe acute respiratory syndrome (SARS) was successfully contained globally by instituting widespread quarantine measures. Although these measures were successful in terminating the outbreak in all areas of the world, the adverse effects of quarantine have not previously been determined in a systematic manner. In this hypothesis-generating study supported by a convenience sample drawn in close temporal proximity to the period of quarantine, we examined the psychological effects of quarantine on persons in Toronto, Canada. The 129 quarantined persons who responded to a Web-based survey exhibited a high prevalence of psychological distress. Symptoms of posttraumatic stress disorder (PTSD) and depression were observed in 28.9% and 31.2% of respondents, respectively. Longer durations of quarantine were associated with an increased prevalence of PTSD symptoms. Acquaintance with or direct exposure to someone with a diagnosis of SARS was also associated with PTSD and depressive symptoms.
PMCID: PMC3323345  PMID: 15324539
SARS; quarantine; post–traumatic stress disorder; depression
21.  Successful control of a Methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit: a retrospective, before-after study 
BMC Infectious Diseases  2013;13:440.
Aim of this study was to provide a detailed description of a Methicillin-resistant Staphylococcus aureus (MRSA) outbreak management strategy in the neonatal intensive care unit of a university hospital.
This was a retrospective, “before-after” study, over two consecutive 18-month periods. The outbreak management strategy was performed by a multidisciplinary team and included: extensive healthcare workers (HCW) involvement, education, continuous hand-hygiene training and active MRSA colonization surveillance. The actions implemented were identified based on an anonymous, voluntary, reporting system, carried out among all the HCW, and regular audit and feedback were provided to the nursing staff.
The main measured outcome was the rate of MRSA infections before and after the implementation of the outbreak management strategy. Piecewise linear Poisson regression was performed and the model adjusted for confounding variables. The secondary outcome was the rate of laboratory-confirmed bloodstream infections before and after the outbreak management strategy. The rates of MRSA colonization, implementation of proposed actions, observed compliance for hand-hygiene and insertion/care of central lines were also recorded during the second period.
1015 newborns were included. The rate of MRSA infections throughout the two periods fell from 3.5 to 0.7 cases per 1000 patient-days (p=0.0005). The piecewise Poisson regression analysis adjusted for confounding variables showed a significant decrease in the MRSA infection rate after the outbreak management strategy (p=0.046). A significant decrease in positive laboratory confirmed blood cultures was observed over the two periods (160 vs 83; p<0.0001). A significant decline in the MRSA colonization rate occurred over the second period (p=0.001); 93% of the proposed actions were implemented. The compliance rate for hand-hygiene and insertion/care of central lines was respectively 95.9% and 62%.
The implementation of multiple, simultaneous, evidence-based management strategies is effective for controlling nosocomial infections. Outbreak management strategies may benefit from tools improving the communication between the institutional and scientific leadership and the ground-level staff. These measures can help to identify individualized solutions addressing specific unit needs.
PMCID: PMC3849690  PMID: 24053628
Quality-improvement; Practices; Newborn; Hospital-acquired infection; Community; Endemic; Voice, Bundle
22.  Temporal Variability and Social Heterogeneity in Disease Transmission: The Case of SARS in Hong Kong 
PLoS Computational Biology  2009;5(8):e1000471.
The extent to which self-adopted or intervention-related changes in behaviors affect the course of epidemics remains a key issue for outbreak control. This study attempted to quantify the effect of such changes on the risk of infection in different settings, i.e., the community and hospitals. The 2002–2003 severe acute respiratory syndrome (SARS) outbreak in Hong Kong, where 27% of cases were healthcare workers, was used as an example. A stochastic compartmental SEIR (susceptible-exposed-infectious-removed) model was used: the population was split into healthcare workers, hospitalized people and general population. Super spreading events (SSEs) were taken into account in the model. The temporal evolutions of the daily effective contact rates in the community and hospitals were modeled with smooth functions. Data augmentation techniques and Markov chain Monte Carlo (MCMC) methods were applied to estimate SARS epidemiological parameters. In particular, estimates of daily reproduction numbers were provided for each subpopulation. The average duration of the SARS infectious period was estimated to be 9.3 days (±0.3 days). The model was able to disentangle the impact of the two SSEs from background transmission rates. The effective contact rates, which were estimated on a daily basis, decreased with time, reaching zero inside hospitals. This observation suggests that public health measures and possible changes in individual behaviors effectively reduced transmission, especially in hospitals. The temporal patterns of reproduction numbers were similar for healthcare workers and the general population, indicating that on average, an infectious healthcare worker did not infect more people than any other infectious person. We provide a general method to estimate time dependence of parameters in structured epidemic models, which enables investigation of the impact of control measures and behavioral changes in different settings.
Author Summary
Recent epidemics have shown that healthcare workers may be overrepresented among cases and how critical it is to protect them. For example, during the 2002–2003 severe acute respiratory syndrome (SARS) epidemics in Hong Kong, 27%of cases were healthcare workers when they were <1% of the population. Better means of protection require understanding how healthcare workers were infected and assessing their role in disease transmission. Here, we describe a method for estimating the temporal profile of the risk of infection and probability of transmission in the community and hospitals. The 2002–2003 SARS outbreak in Hong Kong is used as an example. For the SARS epidemic, we show that the risk of infection in the community and hospitals decreased with time down to zero in hospitals but remained larger in the community. This observation suggests that public health measures and behavioural changes most effectively reduced transmission in hospitals. Besides, we find that the large number of cases observed among healthcare workers is more likely a result of large and sustained exposure to hospitalized cases than to transmission among healthcare workers. These results are of interest to design control measures in the event of an influenza pandemic.
PMCID: PMC2717369  PMID: 19696879
23.  Stigmatization of people living with HIV/AIDS by healthcare workers at a tertiary hospital in KwaZulu-Natal, South Africa: a cross-sectional descriptive study 
BMC Medical Ethics  2013;14(Suppl 1):S6.
The issue of stigma is very important in the battle against HIV/AIDS in Africa since it may affect patient attendance at healthcare centres for obtaining antiretroviral (ARV) medications and regular medical check-ups. Stigmatization creates an unnecessary culture of secrecy and silence based on ignorance and fear of victimization. This study was designed to determine if there is external stigmatization of people living with HIV and AIDS (PLWHA) by health care workers (HCWs) at a tertiary hospital in KwaZulu-Natal (KZN) province, South Africa. The study investigated the impact of knowledge of HIV/AIDS by HCWs on treatment of patients, as well as the comfort level and attitude of HCWs when rendering care to PLWHA.
A descriptive cross sectional study was designed to collect data using an anonymous self-administered structured questionnaire from 334 HCWs. The study was conducted in clinical departments of a large multidisciplinary 922-bed tertiary care teaching hospital in Durban, KZN.
Overall HCWs had an above average knowledge about HIV/AIDS although some gaps in knowledge were identified. Tests of statistical significance showed that there was association between level of education and knowledge of HIV/AIDs (p ≤ 0.001); occupation and knowledge of HIV/AIDS (p ≤ 0.001); and gender and knowledge of HIV/AIDS (p = 0.004). Test for comfort level was only significant for gender, with males showing more comfort and empathy when dealing with PLWHA (p = 0.003). The study also revealed that patients were sometimes tested for HIV without informed consent before surgery, due to fear of being infected, and there was some gossiping about patients' HIV status by HCWs, thereby compromising patient confidentiality. The majority of HCWs showed a willingness to report incidents of stigmatization and discrimination to higher authorities, for better monitoring and control.
Although knowledge, attitude and comfort level of HCWs taking care of PLWHA was above average, enforcement of existing antidiscrimination laws and continuing education in medical ethics and healthcare law, would greatly improve the performance of HCWs taking care of PLWHAs. More psychological support and counselling should be provided to HCWs, to further reduce the impact of stigmatization and discrimination against PLWHA.
PMCID: PMC3878339  PMID: 24564982
HIV/AIDS; Africa; Attitude; Comfort; Discrimination; Healthcare workers; PLWHA; Stigmatization
24.  High Incidence of Hospital Admissions with Multidrug Resistant and Extensively Drug Resistant Tuberculosis among South African Health Care Workers 
Annals of internal medicine  2010;153(8):516-522.
Nosocomial transmission has been described in extensively drug resistant tuberculosis (XDR-TB) and HIV co-infected patients in South Africa. However, little is known about rates of drug-resistant TB among healthcare workers (HCWs) in TB and HIV endemic settings.
To estimate rates of multi-drug resistant tuberculosis (MDR-TB) and XDR-TB hospitalizations among HCWs in KwaZulu-Natal (KZN), South Africa.
Retrospective study of drug-resistant TB patients admitted for the initiation of drug-resistant TB therapy between 2003 and 2008.
A public TB referral hospital in KZN, South Africa.
HCWs admitted with MDR-TB (N=203) or XDR-TB (N=28) were compared with non-HCWs admitted with MDR-TB (N=3807) or XDR-TB (N=344).
Hospital admission rates, hospital admission incidence rate ratios.
Estimated incidence of MDR-TB hospitalization was 64.8/100,000 for HCWs versus 11.9/100,000 for non-HCWs (I.R.R. 5.56 95% C.I. 4.87–6.35). Estimated incidence of XDR-TB hospitalizations was 7.2/100,000 among HCWs versus 1.1/100,000 in non-HCWs (I.R.R. 6.69 95% C.I. 4.38–10.20). A higher percentage of HCWs than non-HCWs with MDR-TB or XDR-TB were female (78% vs. 47%, p<0.001) and fewer HCWs reported previous TB treatment (41% vs. 92%, p<0.001). Prevalence of HIV infection did not differ between HCW and non-HCW (55% vs. 57%, p=0.71), but a higher percentage of HIV infected HCWs were on antiretroviral medications (63% vs. 47%, p<0.001).
HCWs in this HIV-endemic area were substantially more likely to be hospitalized with either MDR-TB or XDR-TB compared to non-HCWs. The increased risk may be explained by occupational exposure and not by other risk factors, underlining the urgent need for TB infection control programs.
Primary Funding Source
No funding was received for this study
PMCID: PMC3074259  PMID: 20956708
25.  Identification and containment of an outbreak of SARS in a community hospital 
Severe acute respiratory syndrome (SARS) is continuing to spread around the world. All hospitals must be prepared to care for patients with SARS. Thus, it is important to understand the transmission of this disease in hospitals and to evaluate methods for its containment in health care institutions. We describe how we cared for the first 2 patients with SARS admitted to our 419-bed community hospital in Richmond Hill, Ont., and the response to a SARS outbreak within our institution.
We collected clinical and epidemiological data about patients and health care workers at our institution who during a 13-day period had a potential unprotected exposure to 2 patients whose signs and symptoms were subsequently identified as meeting the case definition for probable SARS. The index case at our hospital was a patient who was transferred to our intensive care unit (ICU) from a referral hospital on Mar. 16, 2003, where he had been in close proximity to the son of the individual with the first reported case of SARS in Toronto. After 13 days in the ICU, a diagnosis of probable SARS was reached for our index case. Immediately upon diagnosis of our index case, respiratory isolation and barrier precautions were instituted throughout our hospital and maintained for a period of 10 days, which is the estimated maximum incubation period reported for this disease. Aggressive surveillance measures among hospital staff, patients and visitors were also maintained during this time.
During the surveillance period, 15 individuals (10 hospital staff, 3 patients and 2 visitors) were identified as meeting the case definition for probable or suspected SARS, in addition to our index case. All but 1 individual had had direct contact with a symptomatic patient with SARS during the period of unprotected exposure. No additional cases were identified after infection control precautions had been implemented for 8 days. No cases of secondary transmission were identified in the 21 days following the implementation of these precautions at our institution.
SARS can easily be spread by direct personal contact in the hospital setting. We found that the implementation of aggressive infection control measures is effective in preventing further transmission of this disease.
PMCID: PMC155957  PMID: 12771070

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