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1.  The persisting burden of invasive pneumococcal disease in HIV patients: an observational cohort study 
BMC Infectious Diseases  2011;11:314.
Background
The increasing use of highly active antiretroviral therapy (HAART) and pneumococcal immunization along with shifting community exposures may have altered the burden of Streptococcus pneumoniae disease in HIV-infected persons. We describe the burden and risk factors for pneumococcal disease in the modern era of HIV care and evaluate the use of a 23-valent pneumococcal polysaccharide vaccine (PPV-23).
Methods
The incidence of invasive pneumococcal disease (IPD) between January 1st, 2000 and January 1st, 2010 in a regional HIV population in Southern Alberta, Canada was determined by linking comprehensive laboratory and hospital surveillance data. Clinical and epidemiologic data including risk factors for S. pneumoniae, history of pneumococcal immunization, serotypes of infections, and length of any hospitalizations for pneumococcal disease were evaluated with multivariate analysis. CD4 count and viral load at immunization were evaluated with a nested case-control analysis.
Results
In 1946 HIV-patients with 11,099 person-years of follow up, there were 68 distinct episodes of pneumococcal disease occurring in 50 patients. Increased risk was seen if female, age >60, Aboriginal ethnicity, lower education, injection drug use, smoking, nadir CD4 <200/μL, chronic obstructive pulmonary disease, and hepatitis C. Overall, the incidence of IPD was 342/100,000 person-years and was reduced to 187/100,000 within three years of PPV-23 immunization (P < 0.01). Although 78% of patients received PPV-23, 74% of IPD episodes were caused by PPV-23 serotypes. In a case-control analysis, HIV viral load at immunization was significantly predictive of PPV-23 failure, while CD4 count was not. 80% of IPD cases required hospitalization: median length of stay was 7 days (range: 1-71); four patients died.
Conclusions
Despite universal access to intensive measures to prevent pneumococcal disease including the widespread use of HAART and PPV-23 immunization, the incidence of IPD remains high in HIV patients with its associated morbidity and mortality.
doi:10.1186/1471-2334-11-314
PMCID: PMC3226630  PMID: 22078162
2.  Antiretroviral Treatment and Prevention of Peripartum and Postnatal HIV Transmission in West Africa: Evaluation of a Two-Tiered Approach 
PLoS Medicine  2007;4(8):e257.
Background
Highly active antiretroviral treatment (HAART) has only been recently recommended for HIV-infected pregnant women requiring treatment for their own health in resource-limited settings. However, there are few documented experiences from African countries. We evaluated the short-term (4 wk) and long-term (12 mo) effectiveness of a two-tiered strategy of prevention of mother-to-child transmission of HIV (PMTCT) in Africa: women meeting the eligibility criteria of the World Health Organization (WHO) received HAART, and women with less advanced HIV disease received short-course antiretroviral (scARV) PMTCT regimens.
Methods and Findings
The MTCT-Plus Initiative is a multi-country, family-centred HIV care and treatment program for pregnant and postpartum women and their families. Pregnant women enrolled in Abidjan, Côte d'Ivoire received either HAART for their own health or short-course antiretroviral (scARV) PMTCT regimens according to their clinical and immunological status. Plasma HIV-RNA viral load (VL) was measured to diagnose peripartum infection when infants were 4 wk of age, and HIV final status was documented either by rapid antibody testing when infants were aged ≥ 12 mo or by plasma VL earlier. The Kaplan-Meier method was used to estimate the rate of HIV transmission and HIV-free survival. Between August 2003 and June 2005, 107 women began HAART at a median of 30 wk of gestation, 102 of them with zidovudine (ZDV), lamivudine (3TC), and nevirapine (NVP) and they continued treatment postpartum; 143 other women received scARV for PMTCT, 103 of them with sc(ZDV+3TC) with single-dose NVP during labour. Most (75%) of the infants were breast-fed for a median of 5 mo. Overall, the rate of peripartum HIV transmission was 2.2% (95% confidence interval [CI] 0.3%–4.2%) and the cumulative rate at 12 mo was 5.7% (95% CI 2.5%–9.0%). The overall probability of infant death or infection with HIV was 4.3% (95% CI 1.7%–7.0%) at age week 4 wk and 11.7% (95% CI 7.5%–15.9%) at 12 mo.
Conclusions
This two-tiered strategy appears to be safe and highly effective for short- and long-term PMTCT in resource-constrained settings. These results indicate a further benefit of access to HAART for pregnant women who need treatment for their own health.
In an observational cohort study from Côte d'Ivoire, François Dabis and colleagues report on prevention of mother-to-child HIV transmission among women receiving antiretroviral therapy according to World Health Organization recommendations.
Editors' Summary
Background
Effective treatments are available to prevent AIDS in people who are infected with HIV, but not everyone with HIV needs to take medication. Usually, anti-HIV medication is recommended only for those whose immune systems have been significantly affected by the virus, as evidenced by symptoms or by the results of a blood test, the CD4 lymphocyte (“T cell”) count. Treating HIV usually requires a combination of three or more medications. These combinations (called HAART) must be taken every day, can cause complications, and can be expensive.
Worldwide, more than half a million children became infected with HIV each year. Most of these children acquire HIV from their mothers during pregnancy or around the time of birth. If a pregnant woman with HIV takes HAART, her chances of passing HIV to the baby are greatly reduced, but the possible side effects of HAART on the baby are not known. Also, most transmission of HIV from mothers to babies occurs in poor countries where supplies of HAART are limited. For these reasons, World Health Organization (WHO) does not recommend that every pregnant woman receive HAART to prevent HIV transmission to the baby, unless the woman needs HAART for her own health (for example if her T cells are low or she has severe symptoms of HIV infection). For pregnant women with HIV who do not need to take HAART for their own health, less complicated treatments, involving a short course of one or two HIV drugs, can be used to reduce the risk of passing HIV to the baby.
Why Was This Study Done?
The WHO recommendations for HAART in pregnancy are based on the best available evidence, but it is important to know how well they work in actual practice. The authors of this study were providing HIV treatment to pregnant women with HIV in West Africa through an established clinic program in Abidjan, Côte d'Ivoire, and wanted to see how well the WHO recommendations for HAART or short-course treatments, depending on the mother's condition, were working to protect babies from HIV infection.
What Did the Researchers Do and Find?
The researchers studied 250 HIV-infected pregnant women who received HIV medications in the Abidjan program between mid-2003 and mid-2005. In accordance with WHO guidelines, 107 women began HAART for their own health during pregnancy, and 143 women did not qualify for HAART but received other short course treatments (scARV) to prevent HIV transmission to their babies. The authors monitored mothers and babies for treatment side effects and tested the babies for HIV infection up to age 1 y.
They found that HAART was relatively safe during pregnancy, although babies born to women on HAART were more likely (26.3%) to have low birth weight than babies born to women who received scARV (12.4%). Also, 7.5% of women on HAART developed side effects requiring a change in their medications. Combining the results from HAART and scART groups, the chance of HIV transmission around the time of birth was 2.2%, increasing to 5.7% at age 1 y. (Three-quarters of the infants were breast-fed; safe water for mixing formula was not reliably available.) The study found no difference in risk of HIV infection between babies whose mothers received HAART and those whose mothers received scARV according to guidelines.
What Do These Findings Mean?
These results support the safety and effectiveness of the WHO two-tiered approach for preventing mother-to-child transmission. This study was not designed to compare HAART to scART directly, because the women who received HAART were the ones with more advanced HIV infection, which might have affected their babies in many ways.
Compared to earlier pregnancy studies of HAART in rich countries, this study of the WHO approach in West Africa showed similar success in protecting infants from HIV infection around the time of birth. Unfortunately, because formula feeding was not generally available in resource-limited settings, protection declined over the first year of life with breast-feeding, but some protection remained.
This study confirms that close monitoring of pregnant women on HAART is necessary, so that drugs can be changed if side effects develop. The study does not tell us whether using scARV in pregnancy might change the virus in ways that would make it more difficult to treat the same women with HAART later if they needed it. The reason for low birth weight in some babies born to mothers on HAART is unclear. It may be because the women who needed HAART had more severe health problems from their HIV, or it may be a result of the HAART itself.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040257.
World Health Organization has a page on prevention of mother-to-child transmission of HIV
“Women, Children, and HIV” is a resource site from the François Xavier Bagnoud Center and UCSF
The MTCT-Plus initiative at Columbia University supports the programs in Abidjan
doi:10.1371/journal.pmed.0040257
PMCID: PMC1949842  PMID: 17713983
3.  The Effect of Highly Active Antiretroviral Therapy on the Survival of HIV-Infected Children in a Resource-Deprived Setting: A Cohort Study 
PLoS Medicine  2011;8(6):e1001044.
This observational cohort study by Andrew Edmonds and colleagues reports that treatment with highly active antiretroviral therapy (HAART) markedly improves the survival of HIV-infected children in Kinshasa, DRC, a resource-deprived setting.
Background
The effect of highly active antiretroviral therapy (HAART) on the survival of HIV-infected children has not been well quantified. Because most pediatric HIV occurs in low- and middle-income countries, our objective was to provide a first estimate of this effect among children living in a resource-deprived setting.
Methods and Findings
Observational data from HAART-naïve children enrolled into an HIV care and treatment program in Kinshasa, Democratic Republic of the Congo, between December 2004 and May 2010 were analyzed. We used marginal structural models to estimate the effect of HAART on survival while accounting for time-dependent confounders affected by exposure. At the start of follow-up, the median age of the 790 children was 5.9 y, 528 (66.8%) had advanced or severe immunodeficiency, and 405 (51.3%) were in HIV clinical stage 3 or 4. The children were observed for a median of 31.2 mo and contributed a total of 2,089.8 person-years. Eighty children (10.1%) died, 619 (78.4%) initiated HAART, six (0.8%) transferred to a different care provider, and 76 (9.6%) were lost to follow-up. The mortality rate was 3.2 deaths per 100 person-years (95% confidence interval [CI] 2.4–4.2) during receipt of HAART and 6.0 deaths per 100 person-years (95% CI 4.1–8.6) during receipt of primary HIV care only. The mortality hazard ratio comparing HAART with no HAART from a marginal structural model was 0.25 (95% CI 0.06–0.95).
Conclusions
HAART reduced the hazard of mortality in HIV-infected children in Kinshasa by 75%, an estimate that is similar in magnitude but with lower precision than the reported effect of HAART on survival among children in the United States.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
In 2009, an estimated 2.5 million children were living with HIV, the majority of whom (2.3 million) were in sub-Saharan Africa. Most (90%) of these children acquired HIV from their HIV-infected mothers during pregnancy, birth, or breastfeeding, highlighting the importance of giving effective drugs for the prevention of mother to child transmission. As such interventions are still not widely accessible or available in most resource-limited countries, where the burden of HIV is highest, every day an estimated 1,000 children were newly infected with HIV in 2009, but only 360,000 children were receiving highly active antiretroviral therapy (HAART).
Although HAART improves the survival of adults living with HIV, less is known about the degree to which HAART affects the survival of HIV-infected children—although response to antiretroviral treatment is known to differ across age groups. Furthermore, as the course of HIV disease in children is different from that in adults (partly because of the impact of the virus on the immature thymus, which can lead to high HIV RNA viremia and rapid death), it is inappropriate to extrapolate results from studies of adults to pediatric populations. Therefore, it is imperative that the effect of HAART on survival be quantified specifically in children.
Why Was This Study Done?
Most observational studies of the effects of treatment on child survival have been undertaken in high-income countries, such as Italy and the United States. As most children with HIV live in low-resource areas, where multiple factors, such as delayed presentation to care and a higher incidence of co-occurring conditions, might adversely affect treatment outcomes, there is a specific need for information on the effects of HAART in children with HIV living in low-income countries. Although some investigations have taken place in pediatric cohorts from such countries (for example, Côte d'Ivoire, Haiti, Lesotho, Thailand, and Zambia), the effect of HAART on mortality has not been accurately quantified among children in a resource-deprived setting. Therefore, in this observational clinical cohort study, the researchers investigated the effect of HAART on mortality in HIV-infected children in Kinshasa, in the Democratic Republic of the Congo (DRC).
What Did the Researchers Do and Find?
The researchers analyzed data from 790 children enrolled into an HIV program in Kinshasa, DRC, between December 2004 and May 2010 and used a statistical model (marginal structural models) to adjust for time-dependent confounding factors, such as the fact that HAART is typically initiated in sicker patients, for example, those with lower CD4 cell percentages. Assuming that all children starting HAART received it uninterruptedly throughout follow-up, using this statistical model, the researchers were able to compare the hazard ratio of death had all children initiated HAART to that had no children initiated HAART during follow-up.
In the study, 619 out of the 790 children (78.4%) initiated HAART during follow-up and were followed for a median of 31.2 months, with a median of 30 HIV care visits. Of those who started treatment, 110 (17.8%) switched to an alternative regimen because of an adverse event or treatment failure. During the 2,089.8 accrued person-years of follow-up, 80 children (10.1%) died, giving an overall mortality rate of 3.8 deaths per 100 person-years. The unadjusted mortality rate ratio comparing HAART to no HAART was 0.54. Using a marginal structural model, the researchers estimated that compared to no HAART, HAART reduced the hazard (rate) of mortality during follow-up by 75%.
What Do These Findings Mean?
These findings show that treatment with HAART markedly improved the survival of children infected with HIV in Kinshasa, DRC, and suggest that HAART is as effective in improving the survival of HIV-infected children in a severely resource-deprived country (still recovering from civil war) as in more resource-privileged settings—an important finding given that the vast majority of children receiving HAART live in resource-poor areas. This study provides additional evidence that accelerating rollout of antiretroviral therapy to children with HIV in resource-poor countries is lifesaving and effective. Future research needs to address how effective HAART is in understudied populations in resource-poor countries, such as undernourished children or those with co-infections such as tuberculosis.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001044.
The World Health Organization's Web site has more information about the treatment of children living with HIV
Médecins Sans Frontières's Campaign for Access to Essential Medicines Web site has more information on pediatric HAART
doi:10.1371/journal.pmed.1001044
PMCID: PMC3114869  PMID: 21695087
4.  Public-Health and Individual Approaches to Antiretroviral Therapy: Township South Africa and Switzerland Compared 
PLoS Medicine  2008;5(7):e148.
Background
The provision of highly active antiretroviral therapy (HAART) in resource-limited settings follows a public health approach, which is characterised by a limited number of regimens and the standardisation of clinical and laboratory monitoring. In industrialized countries doctors prescribe from the full range of available antiretroviral drugs, supported by resistance testing and frequent laboratory monitoring. We compared virologic response, changes to first-line regimens, and mortality in HIV-infected patients starting HAART in South Africa and Switzerland.
Methods and Findings
We analysed data from the Swiss HIV Cohort Study and two HAART programmes in townships of Cape Town, South Africa. We included treatment-naïve patients aged 16 y or older who had started treatment with at least three drugs since 2001, and excluded intravenous drug users. Data from a total of 2,348 patients from South Africa and 1,016 patients from the Swiss HIV Cohort Study were analysed. Median baseline CD4+ T cell counts were 80 cells/μl in South Africa and 204 cells/μl in Switzerland. In South Africa, patients started with one of four first-line regimens, which was subsequently changed in 514 patients (22%). In Switzerland, 36 first-line regimens were used initially, and these were changed in 539 patients (53%). In most patients HIV-1 RNA was suppressed to 500 copies/ml or less within one year: 96% (95% confidence interval [CI] 95%–97%) in South Africa and 96% (94%–97%) in Switzerland, and 26% (22%–29%) and 27% (24%–31%), respectively, developed viral rebound within two years. Mortality was higher in South Africa than in Switzerland during the first months of HAART: adjusted hazard ratios were 5.90 (95% CI 1.81–19.2) during months 1–3 and 1.77 (0.90–3.50) during months 4–24.
Conclusions
Compared to the highly individualised approach in Switzerland, programmatic HAART in South Africa resulted in similar virologic outcomes, with relatively few changes to initial regimens. Further innovation and resources are required in South Africa to both achieve more timely access to HAART and improve the prognosis of patients who start HAART with advanced disease.
Comparing HIV treatment in Switzerland, where drug selection is individualized, and South Africa, where a programmatic approach is used, Matthias Egger and colleagues find similar virologic outcomes over two years.
Editors' Summary
Background.
Acquired immunodeficiency syndrome (AIDS) has killed more than 25 million people since the first reported case in 1981, and more than 30 million people are now infected with the human immunodeficiency virus (HIV), which causes AIDS. HIV destroys immune system cells (including CD4 cells, a type of lymphocyte), leaving infected individuals susceptible to other infections. Early in the AIDS epidemic, most HIV-infected people died within 10 years of becoming infected. Then, in 1996, highly active antiretroviral therapy (HAART)—a combination of several antiretroviral drugs—was developed. Now, in resource-rich countries, clinicians provide individually tailored care for HIV-infected people by prescribing combinations of antiretroviral drugs chosen from more than 20 approved medicines. The approach to treatment of HIV in developed countries typically also includes frequent monitoring of the amount of virus in patients' blood (viral load), viral resistance testing (to see whether any viruses are resistant to specific antiretroviral drugs), and regular CD4 cell counts (an indication of immune-system health). Since the implementation of these interventions, the health and life expectancy of people with HIV has improved dramatically in these countries.
Why Was This Study Done?
The history of HIV care in resource-poor countries has been very different. Initially, these countries could not afford to provide HAART for their populations. In 2003, however, governments, international agencies, and funding bodies began to implement plans to increase HAART coverage in developing countries. By December 2006, more than a quarter of the HIV-infected people in low- and middle-income countries who urgently needed treatment were receiving HAART. However, instead of individualized treatment, HAART programs in developing countries follow a public-health approach developed by the World Health Organization. That is, drug regimens, clinical decision-making, and clinical and laboratory monitoring are all standardized. This public-health approach takes into account the realities of under-resourced health systems, but is it as effective as the individualized approach? The researchers addressed this question by comparing virologic responses (the effect of treatment on the viral load), changes to first-line (initial) therapy, and deaths in patients receiving HAART in South Africa (public-health approach) and in Switzerland (individualized approach).
What Did the Researchers Do and Find?
The researchers analyzed data collected since 2001 from more than 2,000 patients enrolled in HAART programs in two townships (Gugulethu and Khayelitsha) in Cape Town, South Africa, and from more than 1,000 patients enrolled in the Swiss HIV Cohort Study, a nationwide study of HIV-infected people. The patients in South Africa, who had a lower starting CD4 cell count and were more likely to have advanced AIDS than the patients in Switzerland, started their treatment for HIV infection with one of four first-line therapies, and about a quarter changed to a second-line therapy during the study. By contrast, 36 first-line regimens were used in Switzerland and half the patients changed to a different regimen. Despite these differences, the viral load was greatly reduced within a year in virtually all the patients and viral rebound (an increased viral load after a low measurement) developed within 2 years in a quarter of the patients in both countries. However, more patients died in South Africa than in Switzerland, particularly during the first 3 months of therapy.
What Do These Findings Mean?
These findings suggest that the public-health approach to HAART practiced in South Africa is as effective in terms of virologic outcomes as the individualized approach practiced in Switzerland. This is reassuring because it suggests that “antiretroviral anarchy” (the unregulated use of antiretroviral drugs, interruptions in drug supplies, and the lack of treatment monitoring), which is likely to lead to the emergence of viral resistance, is not happening in South Africa as some experts feared it might. Thus, these findings support the continued rollout of the public-health approach to HAART in resource-poor countries. Conversely, they also suggest that a more standardized approach to HAART could be taken in Switzerland (and in other industrialized countries) without compromising its effectiveness. Finally, the higher mortality in South Africa than in Switzerland, which partly reflects the many patients in South Africa in desperate need of HAART and their more advanced disease at the start of therapy, suggests that HIV-infected patients in South Africa and in other resource-limited countries would benefit from earlier initiation of therapy.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0050148.
The World Health Organization provides information about universal access to HIV treatment (in several languages) and on its recommendations for a public-health approach to antiretroviral therapy for HIV infection
More details on the Swiss HIV Cohort Study and on the studies in Gugulethu and Khayelitsha are available
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
HIV InSite has comprehensive information on all aspects of HIV/AIDS, including detailed information about antiretroviral therapy and links to treatment guidelines for various countries
Information is available from Avert, an international AIDS charity, on HIV and AIDS around the world and on providing AIDS drug treatment for millions
doi:10.1371/journal.pmed.0050148
PMCID: PMC2443185  PMID: 18613745
5.  Serotype-Specific Changes in Invasive Pneumococcal Disease after Pneumococcal Conjugate Vaccine Introduction: A Pooled Analysis of Multiple Surveillance Sites 
PLoS Medicine  2013;10(9):e1001517.
In a pooled analysis of data collected from invasive pneumococcal disease surveillance databases, Daniel Feikin and colleagues examine serotype replacement after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) into national immunization programs.
Please see later in the article for the Editors' Summary
Background
Vaccine-serotype (VT) invasive pneumococcal disease (IPD) rates declined substantially following introduction of 7-valent pneumococcal conjugate vaccine (PCV7) into national immunization programs. Increases in non-vaccine-serotype (NVT) IPD rates occurred in some sites, presumably representing serotype replacement. We used a standardized approach to describe serotype-specific IPD changes among multiple sites after PCV7 introduction.
Methods and Findings
Of 32 IPD surveillance datasets received, we identified 21 eligible databases with rate data ≥2 years before and ≥1 year after PCV7 introduction. Expected annual rates of IPD absent PCV7 introduction were estimated by extrapolation using either Poisson regression modeling of pre-PCV7 rates or averaging pre-PCV7 rates. To estimate whether changes in rates had occurred following PCV7 introduction, we calculated site specific rate ratios by dividing observed by expected IPD rates for each post-PCV7 year. We calculated summary rate ratios (RRs) using random effects meta-analysis. For children <5 years old, overall IPD decreased by year 1 post-PCV7 (RR 0·55, 95% CI 0·46–0·65) and remained relatively stable through year 7 (RR 0·49, 95% CI 0·35–0·68). Point estimates for VT IPD decreased annually through year 7 (RR 0·03, 95% CI 0·01–0·10), while NVT IPD increased (year 7 RR 2·81, 95% CI 2·12–3·71). Among adults, decreases in overall IPD also occurred but were smaller and more variable by site than among children. At year 7 after introduction, significant reductions were observed (18–49 year-olds [RR 0·52, 95% CI 0·29–0·91], 50–64 year-olds [RR 0·84, 95% CI 0·77–0·93], and ≥65 year-olds [RR 0·74, 95% CI 0·58–0·95]).
Conclusions
Consistent and significant decreases in both overall and VT IPD in children occurred quickly and were sustained for 7 years after PCV7 introduction, supporting use of PCVs. Increases in NVT IPD occurred in most sites, with variable magnitude. These findings may not represent the experience in low-income countries or the effects after introduction of higher valency PCVs. High-quality, population-based surveillance of serotype-specific IPD rates is needed to monitor vaccine impact as more countries, including low-income countries, introduce PCVs and as higher valency PCVs are used.
Please see later in the article for the Editors' Summary
Editors’ Summary
Background
Pneumococcal disease–a major cause of illness and death in children and adults worldwide–is caused by Streptococcus pneumoniae, a bacterium that often colonizes the nose and throat harmlessly. Unfortunately, S. pneumoniae occasionally spreads into the lungs, bloodstream, or covering of the brain, where it causes pneumonia, septicemia, and meningitis, respectively. These invasive pneumococcal diseases (IPDs) can usually be successfully treated with antibiotics but can be fatal. Consequently, it is better to avoid infection through vaccination. Vaccination primes the immune system to recognize and attack disease-causing organisms (pathogens) rapidly and effectively by exposing it to weakened or dead pathogens or to pathogen molecules that it recognizes as foreign (antigens). Because there are more than 90 S. pneumoniae variants or “serotypes,” each characterized by a different antigenic polysaccharide (complex sugar) coat, vaccines that protect against S. pneumoniae have to include multiple serotypes. Thus, the pneumococcal conjugate vaccine PCV7, which was introduced into the US infant immunization regimen in 2000, contains polysaccharides from the seven S. pneumoniae serotypes mainly responsible for IPD in the US at that time.
Why Was This Study Done?
Vaccination with PCV7 was subsequently introduced in several other high- and middle-income countries, and IPD caused by the serotypes included in the vaccine declined substantially in children and in adults (because of reduced bacterial transmission and herd protection) in the US and virtually all these countries. However, increases in IPD caused by non-vaccine serotypes occurred in some settings, presumably because of “serotype replacement.” PCV7 prevents both IPD caused by the serotypes it contains and carriage of these serotypes. Consequently, after vaccination, previously less common, non-vaccine serotypes can colonize the nose and throat, some of which can cause IPD. In July 2010, a World Health Organization expert consultation on serotype replacement called for a comprehensive analysis of the magnitude and variability of pneumococcal serotype replacement following PCV7 use to help guide the introduction of PCVs in low-income countries, where most pneumococcal deaths occur. In this pooled analysis of data from multiple surveillance sites, the researchers investigate serotype-specific changes in IPD after PCV7 introduction using a standardized approach.
What Did the Researchers Do and Find?
The researchers identified 21 databases that had data about the rate of IPD for at least 2 years before and 1 year after PCV7 introduction. They estimated whether changes in IPD rates had occurred after PCV7 introduction by calculating site-specific rate ratios–the observed IPD rate for each post-PCV7 year divided by the expected IPD rate in the absence of PCV7 extrapolated from the pre-PCV7 rate. Finally, they used a statistical approach (random effects meta-analysis) to estimate summary (pooled) rate ratios. For children under 5 years old, the overall number of observed cases of IPD in the first year after the introduction of PCV7 was about half the expected number; this reduction in IPD continued through year 7 after PCV7 introduction. Notably, the rate of IPD caused by the S. pneumonia serotypes in PCV7 decreased every year, but the rate of IPD caused by non-vaccine serotypes increased annually. By year 7, the number of cases of IPD caused by non-vaccine serotypes was 3-fold higher than expected, but was still smaller than the decrease in vaccine serotypes, thereby leading to the decrease in overall IPD. Finally, smaller decreases in overall IPD also occurred among adults but occurred later than in children 2 years or more after PCV7 introduction.
What Do These Findings Mean?
These findings show that consistent, rapid, and sustained decreases in overall IPD and in IPD caused by serotypes included in PCV7 occurred in children and thus support the use of PCVs. The small increases in IPD caused by non-vaccine serotypes that these findings reveal are likely to be the result of serotype replacement, but changes in antibiotic use and other factors may also be involved. These findings have several important limitations, however. For example, PCV7 is no longer made and extrapolation of these results to newer PCV10 and PCV13 formulations should be done cautiously. On the other hand, many of the serotypes causing serotype replacement after PCV7 are included in these higher valency vaccines. Moreover, because the data analyzed in this study mainly came from high-income countries, these findings may not be generalizable to low-income countries. Nevertheless, based on their analysis, the researchers make recommendations for the collection and analysis of IPD surveillance data that should allow valid interpretations of the effect of PCVs on IPD to be made, an important requisite for making sound policy decisions about vaccination against pneumococcal disease.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001517.
The US Centers for Disease Control and Prevention provides information for patients and health professionals on all aspects of pneumococcal disease and pneumococcal vaccination, including personal stories
Public Health England provides information on pneumococcal disease and on pneumococcal vaccines
The World Health Organization also provides information on pneumococcal vaccines
The not-for-profit Immunization Action Coalition has information on pneumococcal disease, including personal stories
MedlinePlus has links to further information about pneumococcal infections (in English and Spanish)
The International Vaccine Access Center at Johns Hopkins Bloomberg School of Public Health has more information on introduction of pneumococcal conjugate vaccines in low-income countries
doi:10.1371/journal.pmed.1001517
PMCID: PMC3782411  PMID: 24086113
6.  Evaluation of Coseasonality of Influenza and Invasive Pneumococcal Disease: Results from Prospective Surveillance 
PLoS Medicine  2011;8(6):e1001042.
Using a combination of modeling and statistical analyses, David Fisman and colleagues show that influenza likely influences the incidence of invasive pneumococcal disease by enhancing risk of invasion in colonized individuals.
Background
The wintertime co-occurrence of peaks in influenza and invasive pneumococcal disease (IPD) is well documented, but how and whether wintertime peaks caused by these two pathogens are causally related is still uncertain. We aimed to investigate the relationship between influenza infection and IPD in Ontario, Canada, using several complementary methodological tools.
Methods and Findings
We evaluated a total number of 38,501 positive influenza tests in Central Ontario and 6,191 episodes of IPD in the Toronto/Peel area, Ontario, Canada, between 1 January 1995 and 3 October 2009, reported through population-based surveillance. We assessed the relationship between the seasonal wave forms for influenza and IPD using fast Fourier transforms in order to examine the relationship between these two pathogens over yearly timescales. We also used three complementary statistical methods (time-series methods, negative binomial regression, and case-crossover methods) to evaluate the short-term effect of influenza dynamics on pneumococcal risk. Annual periodicity with wintertime peaks could be demonstrated for IPD, whereas periodicity for influenza was less regular. As for long-term effects, phase and amplitude terms of pneumococcal and influenza seasonal sine waves were not correlated and meta-analysis confirmed significant heterogeneity of influenza, but not pneumococcal phase terms. In contrast, influenza was shown to Granger-cause pneumococcal disease. A short-term association between IPD and influenza could be demonstrated for 1-week lags in both case-crossover (odds ratio [95% confidence interval] for one case of IPD per 100 influenza cases  = 1.10 [1.02–1.18]) and negative binomial regression analysis (incidence rate ratio [95% confidence interval] for one case of IPD per 100 influenza cases  = 1.09 [1.05–1.14]).
Conclusions
Our data support the hypothesis that influenza influences bacterial disease incidence by enhancing short-term risk of invasion in colonized individuals. The absence of correlation between seasonal waveforms, on the other hand, suggests that bacterial disease transmission is affected to a lesser extent.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Although some pathogens (disease-causing organisms) cause illness all year round, others are responsible for seasonal peaks of illness. These peaks occur because of a complex interplay of factors such as the loss of immunity to the pathogen over time and seasonal changes in the pathogen's ability to infect new individuals. Thus, in temperate countries in the northern hemisphere, illness caused by influenza viruses (pathogens that infect the nose, throat, and airways) usually peaks between December and March, perhaps because weather conditions during these months favor the survival of influenza virus in the environment and thus increase its chances of being transferred among people. Another illness that peaks during the winter months in temperate regions is pneumonia, a severe lung infection that is often caused by Streptococcus pneumoniae. These bacteria can colonize the back of the throat without causing disease but occasionally spread into the lungs and other organs where they cause potentially fatal invasive pneumococcal disease (IPD).
Why Was This Study Done?
Although the co-occurrence of seasonal peaks of influenza and IPD is well documented, it is unclear whether (or how) these peaks are causally related. For example, do the peaks of influenza and IPD both occur in the winter because influenza enhances person-to-person transmission of S. pneumoniae (hypothesis 1)? Alternatively, do the diseases co-occur because influenza infection increases the risk of IPD in individuals who are already colonized with S. pneumoniae (hypothesis 2)? Healthcare professionals need to know whether there is a causal relationship between influenza and IPD so that they can target vaccination for both diseases to those individuals most at risk of developing the potentially serious complications of these diseases. In this study, the researchers use several mathematical and statistical methods and data on influenza and IPD collected in Ontario, Canada to investigate the relationship between these seasonal illnesses.
What Did the Researchers Do and Find?
Between January 1995 and October 2009, 38,501 positive influenza tests were recorded in Ontario by the Canadian national influenza surveillance network. Over the same time period, the Toronto Invasive Bacterial Diseases Network (a group of hospitals, laboratories, and doctors that undertakes population-based surveillance for serious bacterial infections in the Toronto and Peel Regions of Ontario) recorded 6,191 IPD episodes. The researchers used a mathematical method called fast Fourier transforms that compares the shape of wave forms to look for any relationship between infections with the two pathogens over yearly timescales (a test of hypothesis 1) and three statistical methods to evaluate the short-term effect of influenza dynamics on IPD risk (tests of hypothesis 2). Although they found wintertime peaks for infections with both pathogens, there was no correlation between the seasonal wave forms for influenza and IPD. That is, there was no relationship between the seasonal patterns of the two infections. By contrast, two of the statistical methods used to test hypothesis 2 revealed a short-term association between infections with influenza and with IPD. Moreover, the third statistical method (the Granger causality Wald test, a type of time-series analysis) provided evidence that data collected at intervals on influenza can be used to predict peaks in IPD infections.
What Do These Findings Mean?
These findings support (but do not prove) the hypothesis that influenza influences IPD incidence by enhancing the short-term risk of bacterial invasion in individuals already colonized with S. pneumoniae, possibly by increasing the permeability of the lining of the airways to bacteria. By contrast, the lack of correlation between the seasonal wave forms for the two diseases suggests that person-to-person transfer of S. pneumoniae is affected by influenza infections to a lesser extent. These findings have important implications for disease control policy. First, they suggest that the increased number of influenza infections in pandemic years may not necessarily be accompanied by a marked surge in IPD. Second, because the findings suggest that some cases of IPD may be influenza-attributable, the extension of influenza vaccination to school-age children and young adults (a group of people at particular risk of IPD who are not normally vaccinated against influenza) could reduce the incidence of IPD as well as the incidence of influenza.
Additional Information
Please access these Web sites via the online version of this summary at http://www.plosone.org/article/info:doi/10.1371/journal.pone.0015493
A related research article by the same authors evaluating links between respiratory viruses and invasive meningococcal disease can be found in PLoS One (e0015493)
The US Centers for Disease Control and Prevention provides information for patients and health professionals on all aspects of seasonal influenza and pneumococcal disease and pneumococcal vaccination
The UK National Health Service Choices website also provides information for patients about seasonal influenza and pneumococcal infection
MedlinePlus has links to further information about influenza and pneumococcal infections (in English and Spanish)
FluWatch is the Canadian national surveillance system for influenza
More information about the Toronto Invasive Bacterial Network is available
The International Association for Ecology and Health provides information on the physical environment and its influence on health
doi:10.1371/journal.pmed.1001042
PMCID: PMC3110256  PMID: 21687693
7.  Influenza-Related Mortality Among Adults Aged 25–54 Years With AIDS in South Africa and the United States of America 
In the absence of highly active therapy antiretroviral (HAART), adults with AIDS experience substantially elevated influenza-associated mortality in South Africa and the United States. This elevated mortality risk declined with widespread HAART introduction in the United States but did not disappear entirely. These data support increased access to HAART and influenza vaccination for human immunodeficiency virus–infected adults globally.
Background. Data are limited on human immunodeficiency virus (HIV)–associated influenza burden in sub-Saharan Africa and the impact of highly active antiretroviral therapy (HAART). We compared influenza-related mortality in adults with AIDS in South Africa and the United States in the pre-HAART era and evaluated mortality trends after HAART introduction in the United States.
Methods. Monthly all-cause and pneumonia and influenza (P&I) mortality rates were compiled for adults with AIDS aged 25–54 years in South Africa (1998–2005) and the United States (pre-HAART era, 1987–1994; HAART era, 1997–2005). We estimated influenza-related deaths as excess mortality above a model baseline during influenza epidemic periods. Influenza-related mortality rates in adults with AIDS were compared with rates for age peers in the general population and adults ≥65 years old.
Results. In the United States before HAART, influenza-related mortality rates in adults with AIDS were 150 (95% confidence interval [CI], 49–460) and 208 (95% CI, 74–583) times greater than in the general population for all-cause and P&I deaths, respectively, and 2.5 (95% CI, 0.9–7.2) and 4.1 (95% CI, 1.4–13) times higher than in elderly adults. After HAART introduction , influenza-related mortality in adults with AIDS dropped 3–6-fold but remained elevated compared with the general population (all-cause relative risk [RR], 44 [95% CI, 16–121]); P&I RR, 73 [95% CI, 47–113]). Influenza-related mortality in South African adults with AIDS in recent years was similar to that in the United States in the pre-HAART era.
Conclusions. Adults with AIDS experience substantially elevated influenza-associated mortality, which declines with widespread HAART introduction but does not disappear. These data support increased access to HAART and influenza vaccination for HIV-infected adults.
doi:10.1093/cid/cis549
PMCID: PMC3657519  PMID: 22715173
8.  Rate of candidiasis among HIV-infected children in Spain in the era of highly active antiretroviral therapy (1997–2008) 
BMC Infectious Diseases  2013;13:115.
Background
Candidiasis is the most common opportunistic infection seen in human immunodeficiency virus (HIV)-infected individuals. The aim of our study was to estimate the candidiasis rate and evaluate its trend in HIV-infected children in Spain during the era of highly active antiretroviral therapy (HAART) compared to HIV-uninfected children.
Methods
We carried out a retrospective study. Data were obtained from the records of the Minimum Basic Data Set from hospitals in Spain. All HIV-infected children were under 17 years of age, and a group of HIV-uninfected children with hospital admissions matching the study group by gender and age were randomly selected. The follow-up period (1997–2008) was divided into three calendar periods: a) From 1997 to 1999 for early-period HAART; b) from 2000 to 2002 for mid-period HAART; and c) from 2003 to 2008 for late-period HAART.
Results
Among children with hospital admissions, HIV-infected children had much higher values than HIV-uninfected children during each of the three calendar periods for overall candidiasis rates (150.0 versus 6.1 events per 1,000 child hospital admissions/year (p < 0.001), 90.3 versus 3.1 (p < 0.001), and 79.3 versus 10.7 (p < 0.001), respectively) and for non-invasive Candida mycosis (ICM) rates (118.5 versus 3.8 (p < 0.001), 85.3 versus 2.3 (p < 0.001), and 80.6 versus 6.0 (p < 0.001), respectively). In addition, HIV-infected children also had higher values of ICM rates than HIV-uninfected children, except during the last calendar period when no significant difference was found (32.4 versus 1.2 (p < 0.001), 11.6 versus 0.4 (p < 0.001), and 4.6 versus 2.3 (p = 0.387), respectively). For all children living with HIV/AIDS, the overall candidiasis rate (events per 1,000 HIV-infected children/year) decreased from 1997–1999 to 2000–2002 (18.8 to 10.6; p < 0.001) and from 2000–2002 to 2003–2008 (10.6 to 5.7; p = 0.060). Within each category of candidiasis, both non-ICM and ICM rates experienced significant decreases from 1997–1999 to 2003–2008 (15.9 to 5.7 (p < 0.001) and 4.1 to 0.3 (p < 0.001), respectively).
Conclusions
Although the candidiasis rate still remains higher than in the general population (from 1997 to 2008), candidiasis diagnoses have decreased among HIV-infected children throughout the HAART era, and it has ceased to be a major health problem among children with HIV infection.
doi:10.1186/1471-2334-13-115
PMCID: PMC3599397  PMID: 23510319
AIDS; Candidiasis; HAART; Infection; Pediatric; Epidemiology
9.  Evolution of Antiretroviral Drug Costs in Brazil in the Context of Free and Universal Access to AIDS Treatment  
PLoS Medicine  2007;4(11):e305.
Background
Little is known about the long-term drug costs associated with treating AIDS in developing countries. Brazil's AIDS treatment program has been cited widely as the developing world's largest and most successful AIDS treatment program. The program guarantees free access to highly active antiretroviral therapy (HAART) for all people living with HIV/AIDS in need of treatment. Brazil produces non-patented generic antiretroviral drugs (ARVs), procures many patented ARVs with negotiated price reductions, and recently issued a compulsory license to import one patented ARV. In this study, we investigate the drivers of recent ARV cost trends in Brazil through analysis of drug-specific prices and expenditures between 2001 and 2005.
Methods and Findings
We compared Brazil's ARV prices to those in other low- and middle-income countries. We analyzed trends in drug expenditures for HAART in Brazil from 2001 to 2005 on the basis of cost data disaggregated by each ARV purchased by the Brazilian program. We decomposed the overall changes in expenditures to compare the relative impacts of changes in drug prices and drug purchase quantities. We also estimated the excess costs attributable to the difference between prices for generics in Brazil and the lowest global prices for these drugs. Finally, we estimated the savings attributable to Brazil's reduced prices for patented drugs. Negotiated drug prices in Brazil are lowest for patented ARVs for which generic competition is emerging. In recent years, the prices for efavirenz and lopinavir–ritonavir (lopinavir/r) have been lower in Brazil than in other middle-income countries. In contrast, the price of tenofovir is US$200 higher per patient per year than that reported in other middle-income countries. Despite precipitous price declines for four patented ARVs, total Brazilian drug expenditures doubled, to reach US$414 million in 2005. We find that the major driver of cost increases was increased purchase quantities of six specific drugs: patented lopinavir/r, efavirenz, tenofovir, atazanavir, enfuvirtide, and a locally produced generic, fixed-dose combination of zidovudine and lamivudine (AZT/3TC). Because prices declined for many of the patented drugs that constitute the largest share of drug costs, nearly the entire increase in overall drug expenditures between 2001 and 2005 is attributable to increases in drug quantities. Had all drug quantities been held constant from 2001 until 2005 (or for those drugs entering treatment guidelines after 2001, held constant between the year of introduction and 2005), total costs would have increased by only an estimated US$7 million. We estimate that in the absence of price declines for patented drugs, Brazil would have spent a cumulative total of US$2 billion on drugs for HAART between 2001 and 2005, implying a savings of US$1.2 billion from price declines. Finally, in comparing Brazilian prices for locally produced generic ARVs to the lowest international prices meeting global pharmaceutical quality standards, we find that current prices for Brazil's locally produced generics are generally much higher than corresponding global prices, and note that these prices have risen in Brazil while declining globally. We estimate the excess costs of Brazil's locally produced generics totaled US$110 million from 2001 to 2005.
Conclusions
Despite Brazil's more costly generic ARVs, the net result of ARV price changes has been a cost savings of approximately US$1 billion since 2001. HAART costs have nevertheless risen steeply as Brazil has scaled up treatment. These trends may foreshadow future AIDS treatment cost trends in other developing countries as more people start treatment, AIDS patients live longer and move from first-line to second and third-line treatment, AIDS treatment becomes more complex, generic competition emerges, and newer patented drugs become available. The specific application of the Brazilian model to other countries will depend, however, on the strength of their health systems, intellectual property regulations, epidemiological profiles, AIDS treatment guidelines, and differing capacities to produce drugs locally.
Amy Nunn and colleagues analyze the cost of antiretroviral drugs in Brazil between 2001 and 2005 and discuss the implications for HIV treatment in other developing countries.
Editors' Summary
Background.
Acquired immunodeficiency syndrome (AIDS) has killed 29 million people since the first case occurred in 1981 and an estimated 40 million people live with HIV/AIDS today. AIDS is caused by the human immunodeficiency virus (HIV), which destroys the immune system. Infected individuals are consequently very susceptible to other infections. Early in the AIDS epidemic, most HIV-positive individuals died within a few years of becoming infected. Then, in 1996, highly active antiretroviral therapy (HAART)—a cocktail of antiretroviral drugs (ARVs)—was developed. For people who could afford HAART (which holds HIV infections in check), AIDS became a chronic disease. People who start HAART must keep taking it or their illness will progress.
Unfortunately, few people in low- and middle-income countries could afford these expensive drugs. In 2001, ARV prices fell in developing countries as AIDS activists and developing country governments challenged pharmaceutical companies about ARV prices, pharmaceutical companies set tiered prices for the low- and middle-income countries and more generic (inexpensive copies of brand-named drugs) ARVs became available. In 2003, the lack of access to HIV/AIDS treatment was declared a global health emergency. Governments, international organizations, and funding bodies began to set targets and provide funds to increase access to HAART in developing countries. By 2007, over 2 million people in low- and middle-income countries had access to HAART, but another 5 million remain in urgent need of drugs for treatment.
Why Was This Study Done?
In 1995, many countries in the world signed the World Trade Organization (WTO) Trade-Related Aspects of Intellectual Property (TRIPS) agreement, which requires countries to acknowledge intellectual property rights for many products, including pharmaceuticals. In 1996, Brazil became the first developing country to commit to and implement policies to provide free and universal access to HAART. Since then, Brazil's successful AIDS treatment program has become a model for the developing world, and 180,000 Brazilians were receiving HAART at the end of 2006. However, as a WTO member that signed on to the TRIPS agreement, Brazil was required to recognize the intellectual property rights of pharmaceutical companies' patented ARVs. As Brazil scaled up treatment in the late 1990s, the cost of treating AIDS patients rose quickly and the country took controversial public policy steps to reduce the cost of providing HAART to people living with HIV/AIDS. Brazil produces several non-patented ARVs locally, and since 2001 has challenged multinational pharmaceutical companies about the prices of patented ARVs. To induce price reductions for patented ARVs, Brazil has threatened to issue compulsory licenses (which under WTO terms allow countries facing a health emergency to produce patented drugs without consent of the company holding the patent). Brazil also recently issued a compulsory license for one ARV.
Although world leaders have set a target of universal access to HAART by 2010, little is known about the long-term costs of AIDS treatment in developing countries. In this study, the researchers have investigated how and why the costs of ARVs changed in Brazil between 2001 and 2005 and discuss the relevance of the Brazilian model for AIDS treatment for other resource-limited settings.
What Did the Researchers Do and Find?
The researchers analyzed the prices for each ARV recommended in Brazil's therapeutic guidelines for adults and estimated the changes in purchase quantities for each between 2001 and 2005. These changes likely stem from the growing number of options in Brazil's treatment guidelines, the steadily rising number of patients commencing treatment, and patients' shifts to second- and third-line treatments when their HIV infection became resistant to first-line drugs or they developed side effects. The researchers report that the generic drugs produced in Brazil were generally more expensive than similar drugs made elsewhere, but Brazil's negotiated drug prices for many patented ARVs were lower than elsewhere. Overall, total annual drug expenditure on ARVs doubled between 2001 and 2005, reaching US$414 million in 2005. Because many drug prices fell sharply as a result of declining patented drug prices over the study period, this increase was mainly attributable to increases in drug quantities purchased. If these quantities had stayed constant, the total annual cost would have increased by only $7 million, to $211 million. Conversely, without the decrease in the price of patented drugs, Brazil would have spent $952 million annually by 2005. If Brazil had enjoyed the lowest global prices for generic medicines, the total costs per year in 2005 would have been $367 million, or nearly $50 million less than the costs Brazil actually realized.
What Do These Findings Mean?
These findings tease out the many factors—clinical, commercial, and political—that affected the total costs of the Brazilian AIDS treatment program between 2001 and 2005.
Brazil's ability to produce generic drugs facilitated Brazil's price negotiations for patented drugs. Although Brazil saved approximately US$1 billion over the study period as a result of declining prices for patented medicines, the cost of producing generic drugs locally has risen while the prices for generic drugs have fallen elsewhere. Brazil's recent decision to import a generic ARV using a compulsory license suggests that the Brazilian model for AIDS treatment continues to evolve.
Questions remain about the precise causes of year-to-year cost trends in Brazil because, for example, the researchers did not have full data on when patients switched from first-line to second- or third-line drugs. The observed steep rise in costs from 2004 to 2005 in particular warrants further analysis. In addition, the findings may not be generalizable to countries with different policies on HIV/AIDS treatment, different access to generic drugs, or different bargaining power with multinational drug companies. Nevertheless, the trends this study highlights provide important information about how AIDS treatment costs are likely to evolve in other developing countries as efforts are made to provide universal access to life-saving ARVs.
Additional Information.
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.0040305.
Information from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
Information from the US Centers for Disease Control and Prevention on global HIV/AIDS topics (in English and Spanish)
HIV InSite, comprehensive and up-to-date information on all aspects of HIV/AIDS from the University of California San Francisco
Information from Avert, an international AIDS charity, on HIV and AIDS in Brazil and on HIV/AIDS treatment and care, including universal access to ARVs
Progress towards universal access to HIV/AIDS treatment, the latest report from the World Health Organization (available in several languages)
The National STD and AIDS Program of Brazil
doi:10.1371/journal.pmed.0040305
PMCID: PMC2071936  PMID: 18001145
10.  Clinical and economic burden of invasive pneumococcal disease in adults: a multicenter hospital-based study 
BMC Infectious Diseases  2013;13:202.
Background
Streptococcus pneumoniae causes a broad spectrum of illnesses ranging from mild upper respiratory tract infections to invasive pneumococcal disease (IPD). Quantitative data on the burden of pneumococcal disease, important for the establishment of appropriate vaccination strategies, is currently lacking in adults.
Methods
This multicenter, retrospective cohort study was designed to estimate the clinical and economic burden of IPD in adults over the last decade. Data were collected from patients with IPD at 10 university hospitals in South Korea. We estimated the proportion of IPD among all hospitalized patients, the case fatality rate, and the direct medical costs of IPD. Data were further analyzed according to age and risk groups.
Results
During the study period, 970 patients with IPD were identified. The mean age for all patients was 60.9 years; patients aged 50–64 years (33.0%) were most numerous, followed by those aged 65–74 years (27.4%). Overall, the proportion of IPD was 0.36 cases/1000 hospitalized patients and the case fatality rate was 30.9%, which increased significantly with age (p < 0.01). The mean direct medical costs were estimated to be US $7,452 without a difference between age and risk groups. On multivariate analysis, old age, advanced ECOG performance status, bacteremic pneumonia, and nosocomial infection were independent risk factors of 30-day case fatality.
Conclusions
The clinical disease burden of IPD increased significantly with age and direct medical costs from IPD were substantial, regardless of age and co-morbid conditions. The current age-based vaccination strategy appears to be appropriate.
doi:10.1186/1471-2334-13-202
PMCID: PMC3660270  PMID: 23641904
Cost of illness; Pneumococcal infection; Pneumococcal vaccines; Streptococcus pneumoniae
11.  Antiretroviral Program Associated with Reduction in Untreated Prevalent Tuberculosis in a South African Township 
Rationale: In 2005, we reported high prevalence of untreated pulmonary tuberculosis (TB) in a South African community. Prevalent untreated TB is the main source of transmission. In settings with large burdens of human immunodeficiency virus (HIV) and TB, highly active antiretroviral therapy (HAART) may contribute to TB control.
Objectives: To assess the community-level impact of HAART on TB prevalence, we repeated a community-based TB prevalence cross-sectional survey in 2008 following HAART roll-out.
Methods: A random 10% adult population sample was identified from the community. Participants provided two sputum specimens for acid-fast bacilli microscopy and TB culture. Oral transudate specimen was collected for anonymous HIV testing, linked to TB diagnosis. An interviewer-administered, structured questionnaire identified TB and HIV history and risk factors.
Measurements and Main Results: In the 2008 survey, 1,250 adults participated (90% response rate); 306 (25%) tested HIV positive, of which 60 (20%) were receiving HAART. A total of 20 TB cases were identified (12 receiving TB treatment), representing a significant decline in prevalence from 3.2 to 1.6% (P = 0.02) between the surveys. TB prevalence in participants not infected with HIV was unchanged (P = 0.90). The decline occurred among participants not infected with HIV, decreasing from 9.2 to 3.6% in 2005 to 2008, respectively (P = 0.003). In participants infected with HIV, prevalence of treated TB declined from 4 to 2.3% (P = 0.06), and untreated TB prevalence from 5.2 to 1.3% (P = 0.02). The proportion of untreated TB in patients receiving HAART decreased significantly, from 22 to 0% (P < 0.001).
Conclusions: Prevalence of undiagnosed TB declined significantly over a period of increasing HAART availability. The decline was predominantly in individuals infected with HIV receiving HAART.
doi:10.1164/rccm.201004-0598OC
PMCID: PMC2970849  PMID: 20558626
tuberculosis; prevalence; human immunodeficiency virus; antiretroviral therapy
12.  The Independent Effect of Highly Active Antiretroviral Therapy on Severe Opportunistic Disease Incidence and Mortality in HIV-infected Adults in Côte d’Ivoire 
Antiviral therapy  2007;12(4):543-551.
Background
Studies in developed countries have shown highly active antiretroviral therapy (HAART) decreases incidence of severe opportunistic diseases (ODs) in HIV-infected patients beyond what is expected from CD4 changes.
Objective
To estimate the independent impact of HAART on reducing ODs and mortality in Côte d’Ivoire.
Methods
Within 2 longitudinal studies of HIV-infected adults (1996–2003), we identified time on cotrimoxazole alone and HAART plus cotrimoxazole. WHO stage 3–4 defining events and severe malaria were divided into those preventable and not preventable with cotrimoxazole. Incidence of ODs by CD4 stratum was estimated using incidence density analysis. CD4 at time of OD was estimated using linear interpolation. Using Poisson regression, we estimated the effect of HAART on OD incidence and mortality by CD4 stratum.
Results
Four hundred forty-six and 135 adults were followed during 6,216 and 3,412 person-months in the cotrimoxazole alone and HAART plus cotrimoxazole periods. There was a CD4-independent risk reduction for ODs and mortality during the HAART plus cotrimoxazole period compared to cotrimoxazole alone, which varied by time on HAART, CD4 stratum, and OD type. It was mainly seen after 6 months on HAART, and for ODs not preventable by cotrimoxazole. The HAART effect differed significantly by CD4 stratum (p=0.02), but was significant in all strata after 6 months on HAART.
Conclusions
In these sub-Saharan African adults, HAART initiation reduced ODs and mortality beyond what was expected through the HAART-induced CD4 increase. Further studies should examine practical implications of this independent “HAART effect” on clinical outcomes in patients on HAART.
PMCID: PMC3073611  PMID: 17668563
HAART; opportunistic disease; opportunistic infection; HIV; mortality
13.  Highly active antiretroviral treatment for the prevention of HIV transmission 
In 2007 an estimated 33 million people were living with HIV; 67% resided in sub-Saharan Africa, with 35% in eight countries alone. In 2007, there were about 1.4 million HIV-positive tuberculosis cases. Globally, approximately 4 million people had been given highly active antiretroviral therapy (HAART) by the end of 2008, but in 2007, an estimated 6.7 million were still in need of HAART and 2.7 million more became infected with HIV.
Although there has been unprecedented investment in confronting HIV/AIDS - the Joint United Nations Programme on HIV/AIDS estimates $13.8 billion was spent in 2008 - a key challenge is how to address the HIV/AIDS epidemic given limited and potentially shrinking resources. Economic disparities may further exacerbate human rights issues and widen the increasingly divergent approaches to HIV prevention, care and treatment.
HIV transmission only occurs from people with HIV, and viral load is the single greatest risk factor for all modes of transmission. HAART can lower viral load to nearly undetectable levels. Prevention of mother to child transmission offers proof of the concept of HAART interrupting transmission, and observational studies and previous modelling work support using HAART for prevention. Although knowing one's HIV status is key for prevention efforts, it is not known with certainty when to start HAART.
Building on previous modelling work, we used an HIV/AIDS epidemic of South African intensity to explore the impact of testing all adults annually and starting persons on HAART immediately after they are diagnosed as HIV positive. This theoretical strategy would reduce annual HIV incidence and mortality to less than one case per 1000 people within 10 years and it would reduce the prevalence of HIV to less than 1% within 50 years. To explore HAART as a prevention strategy, we recommend further discussions to explore human rights and ethical considerations, clarify research priorities and review feasibility and acceptability issues.
doi:10.1186/1758-2652-13-1
PMCID: PMC2822750  PMID: 20205768
14.  Risk Factors for Multidrug-Resistant Invasive Pneumococcal Disease in South Africa, a Setting with High HIV Prevalence, in the Prevaccine Era from 2003 to 2008 
Antimicrobial Agents and Chemotherapy  2012;56(10):5088-5095.
The emergence of multidrug-resistant (MDR) Streptococcus pneumoniae complicates disease management. We aimed to determine risk factors associated with MDR invasive pneumococcal disease (IPD) in South Africa and evaluate the potential for vaccination to reduce disease burden. IPD data collected by laboratory-based surveillance from 2003 through 2008 were analyzed. Multidrug resistance was defined as nonsusceptibility to any three or more different antibiotic classes. Risk factors for multidrug resistance were evaluated using multivariable logistic regression. Of 20,100 cases of IPD identified, 3,708 (18%) had MDR isolates, with the proportion increasing from 16% (461/2,891) to 20% (648/3,326) (P < 0.001) over the study period. Serotypes included in the 13-valent pneumococcal conjugate vaccine (PCV13) accounted for 94% of MDR strains. Significant risk factors for MDR IPD included PCV13 (1,486/6,407; odds ratio [OR] of 6.3; 95% confidence interval [CI] of 5.0 to 7.9) and pediatric (3,382/9,980; OR of 12.8; 95% CI of 10.6 to 15.4) serotypes, age of <5 (802/3,110; OR of 2.0; 95% CI of 1.8 to 2.3) or ≥65 (39/239; OR of 1.5; 95% CI of 1.0 to 2.2) years versus age of 15 to 64 years, HIV infection (975/4,636; OR of 1.5; 95% CI of 1.2 to 1.8), previous antibiotic use (242/803; OR of 1.7; 95% CI of 1.4 to 2.1), previous hospital admissions (579/2,450; OR of 1.2; 95% CI of 1.03 to 1.4), urban location (883/4,375; OR of 2.0; 95% CI of 1.1 to 3.5), and tuberculosis treatment (246/1,021; OR of 1.2; 95% CI of 1.03 to 1.5). MDR IPD prevalence increased over the study period. The effect of many of the MDR risk factors could be reduced by more judicious use of antibiotics. Because PCV13 serotypes account for most MDR infections, pneumococcal vaccination may reduce the prevalence of multidrug resistance.
doi:10.1128/AAC.06463-11
PMCID: PMC3457358  PMID: 22802256
15.  Antiretroviral therapy at a district hospital in Ethiopia prevents death and tuberculosis in a cohort of HIV patients 
Background
Although highly active antiretroviral therapy (HAART) reduces mortality in the developed world, it remains undocumented in resource-poor settings. We assessed the effect of HAART on patient mortality and tuberculosis incidence rate under routine clinical care conditions in Ethiopia. The objective of this study was to assess the effect of HAART on patient mortality and tuberculosis incidence rate under routine clinical care conditions in a resource-limited setting in south Ethiopia. Starting in January 2003, we followed all consecutive adult HIV infected patients who visited the HIV clinic. Since August 2003, we treated patients with HAART. Only basic laboratory services were available.
Results
We followed 185 patients in the pre-HAART cohort and 180 patients in the HAART cohort. The mortality rate was 15.4 per 100 person-years of observation (PYO) in the HAART group and tuberculosis incidence rate was 3.7 per 100 PYO. In the pre-HAART group, the mortality rate was 58.1 per 100 PYO and the tuberculosis incidence rate was 11.1 per 100 PYO. HAART resulted in a 65% decline in mortality (adjusted hazard ratio [95%CI] = 0.35 [0.19–0.63]; P < 0.001). Tuberculosis incidence rate was lower in the HAART group (adjusted hazard ratio [95%CI] = 0.11 [0.03–0.48]; P < 0.01). Most of the deaths occurred during the first three months of treatment.
Conclusion
HAART improved survival and decreased tuberculosis incidence to a level similar to that achieved in the developed countries during the early years of HAART. However, both the mortality and the tuberculosis incidence rate were much higher in terms of absolute figures in this resource-limited setting. Attention should be paid to the early weeks of treatment when mortality is high. The high tuberculosis incidence rate, when coupled with the improved survival, may lead to increased tuberculosis transmission. This highlights the need for strengthening tuberculosis prevention efforts with the scale-up of treatment programmes
doi:10.1186/1742-6405-3-10
PMCID: PMC1475602  PMID: 16600050
16.  Trends in the Incidence of Cancers among HIV-Infected Persons and the Impact of Antiretroviral Therapy: A 20-Year Cohort Study 
AIDS (London, England)  2009;23(1):41-50.
Objective
To describe trends in incidence rates of AIDS-defining cancers (ADCs) and non-AIDS-defining cancers (NADCs) during the HIV epidemic and to evaluate predictors, including the impact of antiretroviral therapy, of cancer development.
Design
Retrospective analysis of a multicenter, prospective natural history study including 4,498 HIV-infected U.S. military beneficiaries with 33,486 person-years of follow-up.
Methods
Predictors evaluated included demographics, clinical data, time-updated CD4 cell counts, HIV viral loads, and antiretroviral history. Time periods were classified as early pre- (1984-1990), late pre- (1991-1995), early post- (1996-2000), and late post-(2001-2006) HAART eras. Cox proportional hazard models were used to evaluate the association of specific factors with cancer.
Results
Ten percent of HIV-infected persons developed cancer. ADC rates increased between the early and late pre-HAART eras (7.6 and 14.2 cases per 1000 person years) and have since declined from 5.4 to 2.7 in the early and late HAART eras, respectively (p<0.001). Rates of NADCs have risen over the four time periods (2.9, 2.8, 4.2, 6.7, p=0.0004). During the late HAART era, 71% of cancers were NADCs. Predictors for ADCs included low CD4 cell count, non-cancer AIDS diagnosis, and lack of HAART. NADCs were predicted by increasing age, Caucasian race (due to skin cancers), and lack of HAART.
Conclusions
Although the rate of ADCs continues to fall, the rate of NADCs is rising and now accounts for the majority of cancers in HIV-infected persons. The development of NADCs is associated with increasing age among HIV patients. HAART is protective for both ADCs and NADCs.
doi:10.1097/QAD.0b013e328317cc2d
PMCID: PMC2727153  PMID: 19050385
Cancer; malignancy; HIV; military; epidemiology; HAART
17.  Switching HIV Treatment in Adults Based on CD4 Count Versus Viral Load Monitoring: A Randomized, Non-Inferiority Trial in Thailand 
PLoS Medicine  2013;10(8):e1001494.
Using a randomized controlled trial, Marc Lallemant and colleagues ask if a CD4-based monitoring and treatment switching strategy provides a similar clinical outcome compared to the standard viral load-based strategy for adults with HIV in Thailand.
Please see later in the article for the Editors' Summary
Background
Viral load (VL) is recommended for monitoring the response to highly active antiretroviral therapy (HAART) but is not routinely available in most low- and middle-income countries. The purpose of the study was to determine whether a CD4-based monitoring and switching strategy would provide a similar clinical outcome compared to the standard VL-based strategy in Thailand.
Methods and Findings
The Programs for HIV Prevention and Treatment (PHPT-3) non-inferiority randomized clinical trial compared a treatment switching strategy based on CD4-only (CD4) monitoring versus viral-load (VL). Consenting participants were antiretroviral-naïve HIV-infected adults (CD4 count 50–250/mm3) initiating non-nucleotide reverse transcriptase inhibitor (NNRTI)-based therapy. Randomization, stratified by site (21 public hospitals), was performed centrally after enrollment. Clinicians were unaware of the VL values of patients randomized to the CD4 arm. Participants switched to second-line combination with confirmed CD4 decline >30% from peak (within 200 cells from baseline) in the CD4 arm, or confirmed VL >400 copies/ml in the VL arm. Primary endpoint was clinical failure at 3 years, defined as death, new AIDS-defining event, or CD4 <50 cells/mm3. The 3-year Kaplan-Meier cumulative risks of clinical failure were compared for non-inferiority with a margin of 7.4%. In the intent to treat analysis, data were censored at the date of death or at last visit. The secondary endpoints were difference in future-drug-option (FDO) score, a measure of resistance profiles, virologic and immunologic responses, and the safety and tolerance of HAART. 716 participants were randomized, 356 to VL monitoring and 360 to CD4 monitoring. At 3 years, 319 participants (90%) in VL and 326 (91%) in CD4 were alive and on follow-up. The cumulative risk of clinical failure was 8.0% (95% CI 5.6–11.4) in VL versus 7.4% (5.1–10.7) in CD4, and the upper-limit of the one-sided 95% CI of the difference was 3.4%, meeting the pre-determined non-inferiority criterion. Probability of switch for study criteria was 5.2% (3.2–8.4) in VL versus 7.5% (5.0–11.1) in CD4 (p = 0.097). Median time from treatment initiation to switch was 11.7 months (7.7–19.4) in VL and 24.7 months (15.9–35.0) in CD4 (p = 0.001). The median duration of viremia >400 copies/ml at switch was 7.2 months (5.8–8.0) in VL versus 15.8 months (8.5–20.4) in CD4 (p = 0.002). FDO scores were not significantly different at time of switch. No adverse events related to the monitoring strategy were reported.
Conclusions
The 3-year rates of clinical failure and loss of treatment options did not differ between strategies although the longer-term consequences of CD4 monitoring would need to be investigated. These results provide reassurance to treatment programs currently based on CD4 monitoring as VL measurement becomes more affordable and feasible in resource-limited settings.
Trial registration
ClinicalTrials.gov NCT00162682
Please see later in the article for the Editors' Summary
Editors' Summary
Background
About 34 million people (most of them living in low-and middle-income countries) are currently infected with HIV, the virus that causes AIDS. HIV infection leads to the destruction of immune system cells (including CD4 cells, a type of white blood cell), leaving infected individuals susceptible to other infections. Early in the AIDS epidemic, most HIV-infected individuals died within 10 years of infection. Then, in 1996, highly active antiretroviral therapy (HAART)—combined drugs regimens that suppress viral replication and allow restoration of the immune system—became available. For people living in affluent countries, HIV/AIDS became a chronic condition but, because HAART was expensive, HIV/AIDS remained a fatal illness for people living in resource-limited countries. In 2003, the international community declared HIV/AIDS a global health emergency and, in 2006, it set the target of achieving universal global access to HAART by 2010. By the end of 2011, 8 million of the estimated 14.8 million people in need of HAART in low- and middle-income countries were receiving treatment.
Why Was This Study Done?
At the time this trial was conceived, national and international recommendations were that HIV-positive individuals should start HAART when their CD4 count fell below 200 cells/mm3 and should have their CD4 count regularly monitored to optimize HAART. In 2013, the World Health Organization (WHO) recommendations were updated to promote expanded eligibility for HAART with a CD4 of 500 cells/mm3 or less for adults, adolescents, and older children although priority is given to individuals with CD4 count of 350 cells/mm3 or less. Because HIV often becomes resistant to first-line antiretroviral drugs, WHO also recommends that viral load—the amount of virus in the blood—should be monitored so that suspected treatment failures can be confirmed and patients switched to second-line drugs in a timely manner. This monitoring and switching strategy is widely used in resource-rich settings, but is still very difficult to implement for low- and middle-income countries where resources for monitoring are limited and access to costly second-line drugs is restricted. In this randomized non-inferiority trial, the researchers compare the performance of a CD4-based treatment monitoring and switching strategy with the standard viral load-based strategy among HIV-positive adults in Thailand. In a randomized trial, individuals are assigned different interventions by the play of chance and followed up to compare the effects of these interventions; a non-inferiority trial investigates whether one treatment is not worse than another.
What Did the Researchers Do and Find?
The researchers assigned about 700 HIV-positive adults who were beginning HAART for the first time to have their CD4 count (CD4 arm) or their CD4 count and viral load (VL arm) determined every 3 months. Participants were switched to a second-line therapy if their CD4 count declined by more than 30% from their peak CD4 count (CD4 arm) or if a viral load of more than 400 copies/ml was recorded (VL arm). The 3-year cumulative risk of clinical failure (defined as death, a new AIDS-defining event, or a CD4 count of less than 50 cells/mm3) was 8% in the VL arm and 7.4% in the CD4 arm. This difference in clinical failure risk met the researchers' predefined criterion for non-inferiority. The probability of a treatment switch was similar in the two arms, but the average time from treatment initiation to treatment switch and the average duration of a high viral load after treatment switch were both longer in the CD4 arm than in the VL arm. Finally, the future-drug-option score, a measure of viral drug resistance profiles, was similar in the two arms at the time of treatment switch.
What Do These Findings Mean?
These findings suggest that, in Thailand, a CD4 switching strategy is non-inferior in terms of clinical outcomes among HIV-positive adults 3 years after beginning HAART when compared to the recommended viral load-based switching strategy and that there is no difference between the strategies in terms of viral suppression and immune restoration after 3-years follow-up. Importantly, however, even though patients in the CD4 arm spent longer with a high viral load than patients in the VL arm, the emergence of HIV mutants resistant to antiretroviral drugs was similar in the two arms. Although these findings provide no information about the long-term outcomes of the two monitoring strategies and may not be generalizable to routine care settings, they nevertheless provide reassurance that using CD4 counts alone to monitor HAART in HIV treatment programs in resource-limited settings is an appropriate strategy to use as viral load measurement becomes more affordable and feasible in these settings.
Additional Information
Please access these websites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001494.
The World Health Organization provides information on all aspects of HIV/AIDS (in several languages); its 2010 recommendations for antiretroviral therapy for HIV infection in adults and adolescents are available as well as the June 2013 Consolidated guidelines on the use of antiretroviral drugs for treating and preventing HIV infection: recommendations for a public health approach
The 2012 UNAIDS World AIDS Day Report provides up-to-date information about the AIDS epidemic and efforts to halt it
Information is available from the US National Institute of Allergy and Infectious Diseases on HIV infection and AIDS
NAM/aidsmap provides basic information about HIV/AIDS and summaries of recent research findings on HIV care and treatment
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on the global HIV/AIDS epidemic, on HIV and AIDS in Thailand, on universal access to AIDS treatment, and on starting, monitoring and switching HIV treatment (in English and Spanish)
The UK National Health Service Choices website provides information (including personal stories) about HIV and AIDS
More information about this trial (the PHPT-3 trial) is available
Patient stories about living with HIV/AIDS are available through Avert; the nonprofit website Healthtalkonline also provides personal stories about living with HIV, including stories about HIV treatment
doi:10.1371/journal.pmed.1001494
PMCID: PMC3735458  PMID: 23940461
18.  Survival during Renal Replacement Therapy among African Americans Infected with HIV Type 1 in Urban Baltimore, Maryland 
Background
African Americans with human immunodeficiency virus type 1 (HIV-1) infection and kidney disease are at increased risk of end-stage renal disease requiring renal replacement therapy (RRT), particularly in urban areas with high rates of poverty and injection drug use. It is unknown how the widespread use of highly active antiretroviral therapy (HAART) has affected survival during RRT in this vulnerable population.
Methods
African American patients infected with HIV-1 who required RRT were identified from 2 cohorts that included 4509 Africans Americans infected with HIV-1 who were recruited during the period 1988–2004 in Baltimore, Maryland. Survival after initiation of RRT was compared for those who initiated treatment in the pre-HAART and the HAART eras using Kaplan-Meier curves. Cox proportional hazards regression analysis was used to adjust for potential confounders.
Results
RRT was initiated in 162 patients (3.6%) during 10.6 years of follow-up (119 during the HAART era). Compared with patients who started RRT in the pre-HAART era, those in the HAART era were older (P< .001) and more likely to have CD4 cell counts of ≥200 cells/mm3 (P = .01). A total of 126 patients (78%) died during follow-up; among those who initiated RRT during the HAART era, 87 deaths occurred (73%). Median survival time in the pre-HAART era was 22.4 months (95% confidence interval [CI], 9.3–30.7); during the HAART era, it was 19.9 months (95% CI, 14.7–26.5; P = .94). In the multiple Cox regression model, factors independently associated with increased mortality included age (hazard ratio [HR], 1.30; 95% CI, 1.06–1.60; P = .01), lower serum albumin level (HR, 0.72; 95% CI, 0.57–0.91; P< .007), lower CD4 cell count (HR, 0.90; 95% CI, 0.82–0.99; P< .03), and the lack of HAART (HR, 0.52; 95% CI, 0.33–0.82; P = .005).
Conclusions
Older age, lower serum albumin level, lower CD4 cell count, and the lack of HAART are independent predictors of poor survival among African Americans infected with HIV-1 undergoing RRT in a resource-limited urban area. RRT survival was similar in the pre-HAART and HAART eras, likely reflecting inadequate HIV treatment in this population.
doi:10.1086/523728
PMCID: PMC4096866  PMID: 18190325
19.  INCREASED INCIDENCE OF ASTHMA IN HIV-INFECTED CHILDREN TREATED WITH HAART IN THE NIH WOMEN AND INFANTS TRANSMISSION STUDY 
BACKGROUND
Immunoreconstitution of HIV-infected (HIV+) patients after treatment with highly antiretroviral therapy (HAART) appears to provoke inflammatory diseases.
OBJECTIVE
Determine whether HIV+ children on HAART (HIV+ HAART+) have a higher incidence of asthma than HIV+ children not on HAART (HIV+ HAART−).
METHODS
To investigate this possibility, 2,664 children (193 HIV+, 2,471 HIV−) born to HIV+ women were evaluated for the incidence and prevalence of asthma (i.e., asthma medication use), and change of CD4+ T cell percentage with time.
RESULTS
The HIV+ HAART+ children had higher CD4+ T cell percentages, lower CD8+ T cell percentages, and lower viral burdens than the HIV+ HAART− children (P≤0.05 to P≤0.01). The cumulative incidence of asthma medication use in HIV+ HAART+ children at 13.5 year rose to 33.5% vs. 11.5% in HIV+ HAART− children (hazard ratio=3.34, P=0.01) and was equal to that in the HIV− children. In children born prior to the HAART era, the prevalence of asthma medication use for HIV+ HAART+ children at 11 years of age was 10.4% vs. 3.8% for HIV+ HAART− children (odds ratio=3.38, P=0.02) and was equal to that of the HIV− children. The rate of change of CD4+ T cells (percent/year) around the time of first asthma medication for HIV+ HAART+ vs. HIV+ HAART− children was 0.81 vs. −1.43 (P=0.01).
CONCLUSION
The increased incidence of asthma in HIV+ HAART+ children may be driven by immunoreconstitution of CD4+ T cells.
CLINICAL IMPLICATIONS
This HIV model of pediatric asthma may yield clues to help explain the epidemic of asthma in the general pediatric population.
doi:10.1016/j.jaci.2008.04.043
PMCID: PMC3246282  PMID: 18547627
pediatric HIV infection; CD4+ T cell mediated induction of asthma; HAART-produced immunoreconstitution
20.  Kidney and liver organ transplantation in persons with human immunodeficiency virus 
Executive Summary
Objective
The objective of this analysis is to determine the effectiveness of solid organ transplantation in persons with end stage organ failure (ESOF) and human immunodeficiency virus (HIV+)
Clinical Need: Condition and Target Population
Patients with end stage organ failure who have been unresponsive to other forms of treatment eventually require solid organ transplantation. Similar to persons who are HIV negative (HIV−), persons living with HIV infection (HIV+) are at risk for ESOF from viral (e.g. hepatitis B and C) and non-viral aetiologies (e.g. coronary artery disease, diabetes, hepatocellular carcinoma). Additionally, HIV+ persons also incur risks of ESOF from HIV-associated nephropathy (HIVAN), accelerated liver damage from hepatitis C virus (HCV+), with which an estimated 30% of HIV positive (HIV+) persons are co-infected, and coronary artery disease secondary to antiretroviral therapy. Concerns that the need for post transplant immunosuppression and/or the interaction of immunosuppressive drugs with antiretroviral agents may accelerate the progression of HIV disease, as well as the risk of opportunistic infections post transplantation, have led to uncertainty regarding the overall benefit of transplantation among HIV+ patients. Moreover, the scarcity of donor organs and their use in a population where the clinical benefit of transplantation is uncertain has limited the availability of organ transplantation to persons living with ESOF and HIV.
With the development of highly active anti retroviral therapy (HAART), which has been available in Canada since 1997, there has been improved survival and health-related quality of life for persons living with HIV. HAART can suppress HIV replication, enhance immune function, and slow disease progression. HAART managed persons can now be expected to live longer than those in the pre-HAART era and as a result many will now experience ESOF well before they experience life-threatening conditions related to HIV infection. Given their improved prognosis and the burden of illness they may experience from ESOF, the benefit of solid organ transplantation for HIV+ patients needs to be reassessed.
Evidence-Based Analysis Methods
Research Questions
What are the effectiveness and cost effectiveness of solid organ transplantation in HIV+ persons with ESOF?
Literature Search
A literature search was performed on September 22, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1, 1996 to September 22, 2009.
Inclusion Criteria
Systematic review with or without a Meta analysis, RCT, Non-RCT with controls
HIV+ population undergoing solid organ transplantation
HIV+ population managed with HAART therapy
Controls include persons undergoing solid organ transplantation who are i) HIV− ii) HCV+ mono-infected, and iii) HIV+ persons with ESOF not transplanted.
Studies that completed and reported results of a Kaplan-Meier Survival Curve analysis.
Studies with a minimum (mean or medium) follow up of 1-year.
English language citations
Exclusion Criteria
Case reports and case series were excluded form this review.
Outcomes of Interest
i) Risk of Death after transplantation
ii) Death censored graft survival (DCGS)
iii) HIV disease progression defined as the post transplant incidence of:
- opportunistic infections or neoplasms,
- CD4+ T-cell count < 200mm3, and
- any detectable level of plasma HIV viral load.
iv) Acute graft rejection,
v) Return to dialysis,
vi) Recurrence of HCV infection
Summary of Findings
No direct evidence comparing an HIV+ cohort undergoing transplantation with the same not undergoing transplantation (wait list) was found in the literature search.
The results of this review are reported for the following comparison cohorts undergoing transplantation:
i) Kidney Transplantation: HIV+ cohort compared with HIV− cohort
ii) Liver Transplantation: HIV+ cohort compared with HIV− negative cohort
iii) Liver Transplantation: HIV+ HCV+ (co-infected) cohort compared with HCV+ (mono-infected) cohort
Kidney Transplantation: HIV+ vs. HIV−
Based on a pooled HIV+ cohort sample size of 285 patients across four studies, the risk of death after kidney transplantation in an HIV+ cohort does not differ to that of an HIV− cohort [hazard ratio (HR): 0.90; 95% CI: 0.36, 2.23]. The quality of evidence supporting this outcome is very low.
Death censored graft survival was reported in one study with an HIV+ cohort sample size of 100, and was statistically significantly different (p=.03) to that in the HIV− cohort (n=36,492). However, the quality of evidence supporting this outcome was determined to be very low. There was also uncertainty in the rate of return to dialysis after kidney transplantation in both the HIV+ and HIV− groups and the effect, if any, this may have on patient survival. Because of the very low quality evidence rating, the effect of kidney transplantation on HIV-disease progression is uncertain.
The rate of acute graft rejection was determined using the data from one study. There was a nonsignificant difference between the HIV+ and HIV− cohorts (OR 0.13; 95% CI: 0.01, 2.64), although again, because of very low quality evidence there is uncertainty in this estimate of effect.
Liver Transplantation: HIV+ vs. HIV−
Based on a combined HIV+ cohort sample size of 198 patient across five studies, the risk of death after liver transplantation in an HIV+ cohort (with at least 50% of the cohort co-infected with HCV+) is statistically significantly 64% greater compared with an HIV− cohort (HR: 1.64; 95% CI: 1.32, 2.02). The quality of evidence supporting this outcome is very low.
Death censored graft survival was reported for an HIV+ cohort in one study (n=11) however the DCGS rate of the contemporaneous control HIV− cohort was not reported. Because of sparse data the quality of evidence supporting this outcome is very low indicating death censored graft survival is uncertain.
Both the CD4+ T-cell count and HIV viral load appear controlled post transplant with an incidence of opportunistic infection of 20.5%. However, the quality of this evidence for these outcomes is very low indicating uncertainty in these effects. Similarly, because of very low quality evidence there is uncertainty in the rate of acute graft rejection among both the HIV+ and HIV− groups
Liver Transplantation: HIV+/HCV+ vs. HCV+
Based on a combined HIV+/HCV+ cohort sample size of 156 from seven studies, the risk of death after liver transplantation is significantly greater (2.8 fold) in a co-infected cohort compared with an HCV+ mono-infected cohort (HR: 2.81; 95% CI: 1.47, 5.37). The quality of evidence supporting this outcome is very low. Death censored graft survival evidence was not available.
Regarding disease progression, based on a combined sample size of 71 persons in the co-infected cohort, the CD4+ T-cell count and HIV viral load appear controlled post transplant; however, again the quality of evidence supporting this outcome is very low. The rate of opportunistic infection in the co-infected cohort was 7.2%. The quality of evidence supporting this estimate is very low, indicating uncertainty in these estimates of effect.
Based on a combined HIV+/HCV+ cohort (n=57) the rate of acute graft rejection does not differ to that of an HCV+ mono-infected cohort (OR: 0.88; 95% CI: 0.44, 1.76). Also based on a combined HIV+/HCV+ cohort (n=83), the rate of HCV+ recurrence does not differ to that of an HCV+ mono-infected cohort (OR: 0.66; 95% CI: 0.27, 1.59). In both cases, the quality of the supporting evidence was very low.
Overall, because of very low quality evidence there is uncertainty in the effect of kidney or liver transplantation in HIV+ persons with end stage organ failure compared with those not infected with HIV. Examining the economics of this issue, the cost of kidney and liver transplants in an HIV+ patient population are, on average, 56K and 147K per case, based on both Canadian and American experiences.
PMCID: PMC3377507  PMID: 23074407
21.  Brief Communication: Economic Comparison of Opportunistic Infection Management With Antiretroviral Treatment in People Living With HIV/AIDS Presenting at an NGO Clinic in Bangalore, India 
Context
Highly active antiretroviral treatment (HAART) usage in India is escalating. With the government of India launching the free HAART rollout as part of the "3 by 5" initiative, many people living with HIV/AIDS (PLHA) have been able to gain access to HAART medications. Currently, the national HAART centers are located in a few district hospitals (in the high- and medium-prevalence states) and have very stringent criteria for enrolling PLHA. Patients who do not fit these criteria or patients who are too ill to undergo the prolonged wait at the government hospitals avail themselves of nongovernment organization (NGO) services in order to take HAART medications. In addition, the government program has not yet started providing second-line HAART (protease inhibitors). Hence, even with the free HAART rollout, NGOs with the expertise to provide HAART continue to look for funding opportunities and other innovative ways of making HAART available to PLHA. Currently, no study from Indian NGOs has compared the direct and indirect costs of solely managing opportunistic infections (OIs) vs HAART.
Objective
Compare direct medical costs (DMC) and nonmedical costs (NMC) with 2005 values accrued by the NGO and PLHA, respectively, for either HAART or exclusive OI management.
Study design
Retrospective case study comparison.
Setting
Low-cost community care and support center - Freedom Foundation (NGO, Bangalore, south India).
Patients
Retrospective analysis data on PLHA accessing treatment at Freedom Foundation between January 1, 2003 and January 1, 2005. The HAART arm included case records of PLHA who initiated HAART at the center, had frequent follow-up, and were between 18 and 55 years of age. The OI arm included records of PLHA who were also frequently followed up, who were in the same age range, who had CD4+ cell counts < 200/microliter (mcL) or an AIDS-defining illness, and who were not on HAART (solely for socioeconomic reasons). A total of 50 records were analyzed. Expenditures on medication, hospitalization, diagnostics, and NMC (such as food and travel for a caregiver) were calculated for each group.
Results
At 2005 costs, the median DMC plus NMC in the OI group was 21,335 Indian rupees (Rs) (mean Rs 24,277/-) per patient per year (pppy) (US $474). In the HAART group, the median DMC plus NMC was Rs 18,976/- (mean Rs 21,416/-) pppy (US $421). Median DMC plus NMC pppy in the OI arm was Rs 13623.7/- paid by NGO and Rs 1155/- paid by PLHA. Median DMC and NMC pppy in the HAART arm were Rs 1425/- paid by NGO and Rs 17,606/- paid by PLHA.
Conclusion
Good health at no increased expenditure justifies providing PLHA with HAART even in NGO settings.
doi:10.1186/1758-2652-8-4-24
PMCID: PMC2765856
22.  The impact of highly active antiretroviral therapy on prevalence and incidence of cervical human papillomavirus infections in HIV-positive adolescents 
BMC Infectious Diseases  2010;10:295.
Background
The implementation of highly active antiretroviral therapy (HAART) among HIV-positive patients results in immune reconstitution, slower progression of HIV disease, and a decrease in the occurrence of opportunistic infections. However, the impact of HAART on cervical human papillomavirus (HPV) infection, clearance, and persistence in high-risk adolescents remains controversial.
Methods
HIV-positive and high-risk HIV-negative female adolescents were enrolled in the Reaching for Excellence in Adolescent Care and Health (REACH) longitudinal cohort study. At each semi-annual clinical visit, cervical lavage samples were tested for 30 HPV types. Type-specific and carcinogenic risk-specific HPV prevalence and incidence were compared in 373 eligible participants: 146 HIV-negative female adolescents with a median follow-up of 721.5 [IQR: 483-1301] days and 227 HIV-positive female adolescents. Of the 227 HIV-positive participants, a fixed set (n = 100) were examined both before and after HAART initiation; 70 were examined only before HAART initiation; and 57 were examined only after HAART initiation, with overall median follow-up of 271 [IQR: 86.5-473] and 427.25 [IQR: 200-871] days respectively for before and after HAART initiation.
Results
Of the 373 eligible participants, 262 (70%) were infected with at least one type of HPV at baseline, and 78 of the remaining 111 (70%) became infected with at least one type of HPV by the end of the study. Overall, the incidence and prevalence of HPV types 58, 53/66, 68/70, and 31/33/35 were much higher than the established carcinogenic and HPV vaccine types 16 and 18, especially in HIV-positive females both before and after HAART initiation. Baseline prevalence for individual high-risk HPV types ranged, depending on type, from 0.7-10%, 1-17%, and 1-18% in the HIV-negative group, the HIV-positive before HAART initiation group, and the HIV-positive after HAART initiation group, respectively. Likewise, the incidence ranged, depending on HPV type, from 0.64-9.83 cases/100 PY, 3.00-12.80 cases/100 PY, and 1.49-17.05 cases/100 PY in the three groups, respectively. The patterns of each HPV type infection, clearance, and persistence did not differ considerably before or after the introduction of HAART and were clearly independent of CD4+ change within the short post-HAART follow-up period.
Conclusions
HAART did not immediately affect the incidence of type-specific HPV infections within a short-period follow-up; however, future studies are warranted in larger populations to evaluate HAART's impact over longer periods.
doi:10.1186/1471-2334-10-295
PMCID: PMC2965148  PMID: 20946655
23.  Effect of Pneumococcal Conjugate Vaccination on Serotype-Specific Carriage and Invasive Disease in England: A Cross-Sectional Study 
PLoS Medicine  2011;8(4):e1001017.
A cross sectional study by Stefan Flasche and coworkers document the serotype replacement of Streptococcus pneumoniae that has occurred in England since the introduction of PCV7 vaccination.
Background
We investigated the effect of the 7-valent pneumococcal conjugate vaccine (PCV7) programme in England on serotype-specific carriage and invasive disease to help understand its role in serotype replacement and predict the impact of higher valency vaccines.
Methods and Findings
Nasopharyngeal swabs were taken from children <5 y old and family members (n = 400) 2 y after introduction of PCV7 into routine immunization programs. Proportions carrying Streptococcus pneumoniae and serotype distribution among carried isolates were compared with a similar population prior to PCV7 introduction. Serotype-specific case∶carrier ratios (CCRs) were estimated using national data on invasive disease. In vaccinated children and their contacts vaccine-type (VT) carriage decreased, but was offset by an increase in non-VT carriage, with no significant overall change in carriage prevalence, odds ratio 1.06 (95% confidence interval 0.76–1.49). The lower CCRs of the replacing serotypes resulted in a net reduction in invasive disease in children. The additional serotypes covered by higher valency vaccines had low carriage but high disease prevalence. Serotype 11C emerged as predominant in carriage but caused no invasive disease whereas 8, 12F, and 22F emerged in disease but had very low carriage prevalence.
Conclusion
Because the additional serotypes included in PCV10/13 have high CCRs but low carriage prevalence, vaccinating against them is likely to significantly reduce invasive disease with less risk of serotype replacement. However, a few serotypes with high CCRs could mitigate the benefits of higher valency vaccines. Assessment of the effect of PCV on carriage as well as invasive disease should be part of enhanced surveillance activities for PCVs.
Please see later in the article for the Editors' Summary
Editors' Summary
Background
Pneumococcal diseases—major causes of illness and death in children and adults worldwide—are caused by Streptococcus pneumoniae, a bacterium that often colonizes the nasopharynx (the area of the throat behind the nose). Carriage of S. pneumoniae bacteria does not necessarily cause disease. However, these bacteria can cause local, noninvasive diseases such as ear infections and sinusitis and, more rarely, they can spread into the lungs, the bloodstream, or the covering of the brain, where they cause pneumonia, septicemia, and meningitis, respectively. Although these invasive pneumococcal diseases (IPDs) can be successfully treated if administered early, they can be fatal. Consequently, it is better to protect people against IPDs through vaccination than risk infection. Vaccination primes the immune system to recognize and attack disease-causing organisms (pathogens) rapidly and effectively by exposing it to weakened or dead pathogens or to pathogen molecules (antigens) that it recognizes as foreign.
Why Was This Study Done?
There are more than 90 S. pneumoniae variants or “serotypes” characterized by different polysaccharide (complex sugar) coats, which trigger the immune response against S. pneumoniae and determine each serotype's propensity to cause IPD. The pneumococcal conjugate vaccine PCV7 contains polysaccharides (linked to a protein carrier) from the seven serotypes mainly responsible for IPD in the US in 2000 when routine childhood PCV7 vaccination was introduced in that country. PCV7 prevents both IPD caused by the serotypes it contains and carriage of these serotypes, which means that, after vaccination, previously uncommon, nonvaccine serotypes can colonize the nasopharynx. If these serotypes have a high invasiveness potential, then “serotype replacement” could reduce the benefits of vaccination. In this cross-sectional study (a study that investigates the relationship between a disease and an intervention in a population at one time point), the researchers investigate the effect of the UK PCV7 vaccination program (which began in 2006) on serotype-specific carriage and IPD in England to understand the role of PCV7 in serotype replacement and to predict the likely impact of vaccines containing additional serotypes (higher valency vaccines).
What Did the Researchers Do and Find?
The researchers examined nasopharyngeal swabs taken from PCV7-vaccinated children and their families for S. pneumoniae, determined the serotype of any bacteria they found, and compared the proportion of people carrying S. pneumoniae (carrier prevalence) and the distribution of serotypes in this study population and in a similar population that was studied in 2000/2001, before the PCV vaccination program began. Overall, there was no statistically significant change in carrier prevalence, but carriage of vaccine serotypes decreased in vaccinated children and their contacts whereas carriage of nonvaccine serotypes increased. The serotype-specific case-to-carrier ratios (CCRs; a measure of serotype invasiveness that was estimated using national IPD data) of the replacing serotypes were generally lower than those of the original serotypes, which resulted in a net reduction in IPD in children. Moreover, before PCV7 vaccination began, PCV7-included serotypes were responsible for similar proportions of pneumococcal carriage and disease; afterwards, the additional serotypes present in the higher valency vaccines PVC10 and PVC13 were responsible for a higher proportion of disease than carriage. Finally, three serotypes not present in the higher valency vaccines with outstandingly high CCRs (high invasiveness potential) are identified.
What Do These Findings Mean?
These findings document the serotype replacement of S. pneumoniae that has occurred in England since the introduction of PCV7 vaccination and highlight the importance of assessing the effects of pneumococcal vaccines on carriage as well as on IPDs. Because the additional serotypes included in PCV10 and PCV13 have high CCRs but low carriage prevalence and because most of the potential replacement serotypes have low CCRs, these findings suggest that the introduction of higher valency vaccines should further reduce the occurrence of invasive disease with limited risk of additional serotype replacement. However, the emergence of a few serotypes that have high CCRs but are not included in PCV10 and PCV13 might mitigate the benefits of higher valency vaccines. In other words, although the recent introduction of PCV13 into UK vaccination schedules is likely to have an incremental benefit on the reduction of IPD compared to PCV7, this benefit might be offset by increases in the carriage of some high CCR serotypes. These serotypes should be considered for inclusion in future vaccines.
Additional Information
Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1001017.
The US Centers for Disease Control and Prevention provides information for patients and health professionals on all aspects of pneumococcal disease and pneumococcal vaccination
The US National Foundation for Infectious Diseases has a fact sheet on pneumococcal diseases
The UK Health Protection Agency provides information on pneumococcal disease and on pneumococcal vaccines
The World Health Organization also provides information on pneumococcal vaccines
MedlinePlus has links to further information about pneumococcal infections (in English and Spanish)
doi:10.1371/journal.pmed.1001017
PMCID: PMC3071372  PMID: 21483718
24.  The Impact of HAART on the Respiratory Complications of HIV Infection: Longitudinal Trends in the MACS and WIHS Cohorts 
PLoS ONE  2013;8(3):e58812.
Objective
To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART).
Design
Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women’s Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively.
Methods
Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era.
Results
Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2–2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3–1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8–2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02–8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3–1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5–2.4; p<0.001).
Conclusion
HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality.
doi:10.1371/journal.pone.0058812
PMCID: PMC3595204  PMID: 23554932
25.  Cancer incidence in the Multicenter AIDS Cohort Study before and during the HAART era: 1984–2007 
Cancer  2010;116(23):5507-5516.
Background
The incidence of Kaposi’s sarcoma (KS) and non-Hodgkin’s lymphoma (NHL) among human immunodeficiency virus (HIV)-infected individuals declined following the introduction of highly active antiretroviral therapy (HAART) in the mid 1990s, but the cancer risk associated with HIV infection during the HAART era remains to be clarified.
Methods
We compared cancer incidence among HIV-infected and -uninfected participants in the Multicenter AIDS Cohort Study (MACS) between 1984 and 2007 to the expected incidence using US population-based data from the Surveillance, Epidemiology, and End Results (SEER) Program, and we compared age and race adjusted cancer incidence rates by HIV status and over time within the MACS. Exact statistical methods were used for all analyses.
Results
933 incident cancers were observed during 77,320 person-years of follow-up. Compared to SEER, MACS HIV-infected men had significantly (p<0.05) elevated rates of KS (standardized incidence ratio (SIR)=139.10), NHL (SIR=36.80), Hodgkin’s lymphoma (HL) (SIR=7.30), and anal cancer (SIR=25.71). Within MACS, HIV infection was independently associated with each of these cancers across the entire follow-up period, and KS (incidence rate ratio (IRR)=54.93), NHL (IRR=11.18), and anal cancer (IRR=18.50) were each significantly elevated among HIV-infected men during the HAART era. Among these men, the incidence of KS and NHL declined (IRR=0.13 and 0.23, respectively), anal cancer incidence increased (IRR=5.84), and HL incidence remained statistically unchanged (IRR=0.75) from the pre-HAART to the HAART era.
Conclusion
Cancer risk remains elevated among HIV-infected men who have sex with men, highlighting the continuing need for appropriate cancer screening in this population.
doi:10.1002/cncr.25530
PMCID: PMC2991510  PMID: 20672354
HIV infection; cancer incidence; malignancy; AIDS-defining malignancy; HAART

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