Search tips
Search criteria

Results 1-25 (43)

Clipboard (0)

Select a Filter Below

more »
Year of Publication
more »
1.  Addressing the Achilles' Heel in the HIV Care Continuum for the Success of a Test-and-Treat Strategy to Achieve an AIDS-Free Generation 
Mathematical models and recent data from ecological, observational, and experimental studies show that antiretroviral therapy (ART) is effective for both treatment and prevention of HIV, validating the treatment as prevention (TasP) approach. Data from a variety of settings, including resource-rich and -limited sites, show that patient attrition occurs at each stage of the human immunodeficiency virus (HIV) treatment cascade, starting with the percent unaware of their HIV infection in a population and linkage to care after diagnosis, assessment of ART readiness, receipt of ART, and finally long-term virologic suppression. Therefore, in order to implement TasP, we must first define practical and effective linkage to care, acceptability of treatment, and adherence and retention monitoring strategies, as well as the cost-effectiveness of such strategies. Ending this pandemic will require the combination of political will, resources, and novel effective interventions that are not only feasible and cost effective but also likely to be used in combination across successive steps on the HIV treatment cascade.
PMCID: PMC4141496  PMID: 24926028
HIV; ART; treatment as prevention; test-and-treat; treatment cascade
2.  Hormonal Contraception and the Risk of HIV Acquisition: An Individual Participant Data Meta-analysis 
PLoS Medicine  2015;12(1):e1001778.
In a meta-analysis of individual participant data, Charles Morrison and colleagues explore the association between hormonal contraception use and risk of HIV infection in sub-Saharan Africa.
Observational studies of a putative association between hormonal contraception (HC) and HIV acquisition have produced conflicting results. We conducted an individual participant data (IPD) meta-analysis of studies from sub-Saharan Africa to compare the incidence of HIV infection in women using combined oral contraceptives (COCs) or the injectable progestins depot-medroxyprogesterone acetate (DMPA) or norethisterone enanthate (NET-EN) with women not using HC.
Methods and Findings
Eligible studies measured HC exposure and incident HIV infection prospectively using standardized measures, enrolled women aged 15–49 y, recorded ≥15 incident HIV infections, and measured prespecified covariates. Our primary analysis estimated the adjusted hazard ratio (aHR) using two-stage random effects meta-analysis, controlling for region, marital status, age, number of sex partners, and condom use. We included 18 studies, including 37,124 women (43,613 woman-years) and 1,830 incident HIV infections. Relative to no HC use, the aHR for HIV acquisition was 1.50 (95% CI 1.24–1.83) for DMPA use, 1.24 (95% CI 0.84–1.82) for NET-EN use, and 1.03 (95% CI 0.88–1.20) for COC use. Between-study heterogeneity was mild (I2 < 50%). DMPA use was associated with increased HIV acquisition compared with COC use (aHR 1.43, 95% CI 1.23–1.67) and NET-EN use (aHR 1.32, 95% CI 1.08–1.61). Effect estimates were attenuated for studies at lower risk of methodological bias (compared with no HC use, aHR for DMPA use 1.22, 95% CI 0.99–1.50; for NET-EN use 0.67, 95% CI 0.47–0.96; and for COC use 0.91, 95% CI 0.73–1.41) compared to those at higher risk of bias (pinteraction = 0.003). Neither age nor herpes simplex virus type 2 infection status modified the HC–HIV relationship.
This IPD meta-analysis found no evidence that COC or NET-EN use increases women’s risk of HIV but adds to the evidence that DMPA may increase HIV risk, underscoring the need for additional safe and effective contraceptive options for women at high HIV risk. A randomized controlled trial would provide more definitive evidence about the effects of hormonal contraception, particularly DMPA, on HIV risk.
Editors’ Summary
AIDS has killed about 36 million people since the first recorded case of the disease in 1981. About 35 million people (including 25 million living in sub-Saharan Africa) are currently infected with HIV, the virus that causes AIDS, and every year, another 2.3 million people become newly infected with HIV. At the beginning of the epidemic, more men than women were infected with HIV. Now, about half of all adults infected with HIV are women. In 2013, almost 60% of all new HIV infections among young people aged 15–24 years occurred among women, and it is estimated that, worldwide, 50 young women are newly infected with HIV every hour. Most women become infected with HIV through unprotected intercourse with an infected male partner—biologically, women are twice as likely to become infected through unprotected intercourse as men. A woman’s risk of becoming infected with HIV can be reduced by abstaining from sex, by having one or a few partners, and by always using condoms.
Why Was This Study Done?
Women and societies both benefit from effective contraception. When contraception is available, women can avoid unintended pregnancies, fewer women and babies die during pregnancy and childbirth, and maternal and infant health improves. However, some (but not all) observational studies (investigations that measure associations between the characteristics of participants and their subsequent development of specific diseases) have reported an association between hormonal contraceptive use and an increased risk of HIV acquisition by women. So, does hormonal contraception increase the risk of HIV acquisition among women or not? Here, to investigate this question, the researchers undertake an individual participant data meta-analysis of studies conducted in sub-Saharan Africa (a region where both HIV infection and unintended pregnancies are common) to compare the incidence of HIV infection (the number of new cases in a population during a given time period) among women using and not using hormonal contraception. Meta-analysis is a statistical method that combines the results of several studies; an individual participant data meta-analysis combines the data recorded for each individual involved in the studies rather than the aggregated results from each study.
What Did the Researchers Do and Find?
The researchers included 18 studies that measured hormonal contraceptive use and incident HIV infection among women aged 15–49 years living in sub-Saharan Africa in their meta-analysis. More than 37,000 women took part in these studies, and 1,830 became newly infected with HIV. Half of the women were not using hormonal contraception, a quarter were using depot-medroxyprogesterone acetate (DMPA; an injectable hormonal contraceptive), and the remainder were using combined oral contraceptives (COCs) or norethisterone enanthate (NET-EN, another injectable contraceptive). After adjustment for other factors likely to influence HIV acquisition (for example, condom use), women using DMPA had a 1.5-fold increased risk of HIV acquisition compared to women not using hormonal contraception. There was a slightly increased risk of HIV acquisition among women using NET-EN compared to women not using hormonal contraception, but this increase was not statistically significant (it may have happened by chance alone). There was no increased risk of HIV acquisition associated with COC use. DMPA use was associated with a 1.43-fold and 1.32-fold increased risk of HIV acquisition compared with COC and NET-EN use, respectively. Finally, neither age nor herpes simplex virus 2 infection status modified the effect of hormonal contraceptive use on HIV acquisition.
What Do These Findings Mean?
The findings of this individual patient data meta-analysis provide no evidence that COC or NET-EN use increases a woman’s risk of acquiring HIV, but add to the evidence suggesting that DMPA use increases the risk of HIV acquisition. These findings are likely to be more accurate than those of previous meta-analyses that used aggregated data but are likely to be limited by the quality, design, and representativeness of the studies included in the analysis. These findings nevertheless highlight the need to develop additional safe and effective contraceptive options for women at risk of HIV, particularly those living in sub-Saharan Africa, where although contraceptive use is generally low, DMPA is the most widely used hormonal contraceptive. In addition, these findings highlight the need to initiate randomized controlled trials to provide more definitive evidence of the effects of hormonal contraception, particularly DMPA, on HIV risk.
Additional Information.
Please access these websites via the online version of this summary at
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, including personal stories about living with HIV/AIDS and a news report on this meta-analysis
Information is available from Avert, an international AIDS charity, on many aspects of HIV/AIDS, including detailed information on women, HIV, and AIDS, and on HIV and AIDS in South Africa (in English and Spanish); personal stories of women living with HIV are available
The World Health Organization provides information on all aspects of HIV/AIDS (in several languages); information about a 2012 WHO technical consultation about hormonal contraception and HIV
The 2013 UNAIDS World AIDS Day report provides up-to-date information about the AIDS epidemic and efforts to halt it; UNAIDS also provides information about HIV and hormonal contraception
PMCID: PMC4303292  PMID: 25612136
3.  Daily Acyclovir to Decrease Herpes Simplex Virus Type 2 (HSV-2) Transmission from HSV-2/HIV-1 Coinfected Persons: A Randomized Controlled Trial 
The Journal of Infectious Diseases  2013;208(9):1366-1374.
Background. Daily suppressive therapy with valacyclovir reduces risk of sexual transmission of herpes simplex virus type 2 (HSV-2) in HSV-2–serodiscordant heterosexual couples by 48%. Whether suppressive therapy reduces HSV-2 transmission from persons coinfected with HSV-2 and human immunodeficiency virus type 1 (HIV-1) is unknown.
Methods. Within a randomized trial of daily acyclovir 400 mg twice daily in African HIV-1 serodiscordant couples, in which the HIV-1–infected partner was HSV-2 seropositive, we identified partnerships in which HIV-1–susceptible partners were HSV-2 seronegative to estimate the effect of acyclovir on risk of HSV-2 transmission.
Results. We randomly assigned 911 HSV-2/HIV-1–serodiscordant couples to daily receipt of acyclovir or placebo. We observed 68 HSV-2 seroconversions, 40 and 28 in acyclovir and placebo groups, respectively (HSV-2 incidence, 5.1 cases per 100 person-years; hazard ratio [HR], 1.35 [95% confidence interval, .83–2.20]; P = .22). Among HSV-2–susceptible women, vaginal drying practices (adjusted HR, 44.35; P = .004) and unprotected sex (adjusted HR, 9.91; P = .002) were significant risk factors for HSV-2 acquisition; having more children was protective (adjusted HR, 0.47 per additional child; P = .012). Among HSV-2–susceptible men, only age ≤30 years was associated with increased risk of HSV-2 acquisition (P = .016).
Conclusions. Treatment of African HSV-2/HIV-1–infected persons with daily suppressive acyclovir did not decrease risk of HSV-2 transmission to susceptible partners. More-effective prevention strategies to reduce HSV-2 transmission from HIV-1–infected persons are needed.
PMCID: PMC3789565  PMID: 23901094
HSV-2; HIV-1; acyclovir; transmission; serodiscordant couples; Africa
4.  The application of eDNA for monitoring of the Great Crested Newt in the UK 
Ecology and Evolution  2014;4(21):4023-4032.
Current ecological surveys for great crested newts are time-consuming and expensive and can only be carried out within a short survey window. Additional survey methods which would facilitate the detection of rare or protected species such as the great crested newt (Triturus cristatus) would be extremely advantageous. Environmental DNA (eDNA) analysis has been utilized for the detection of great crested newts in Denmark. Here, the same methodology has been applied to water samples taken from UK ponds concurrently with conventional field surveying techniques. Our eDNA analysis exhibited an 84% success rate with a kappa coefficient of agreement between field and eDNA surveys of 0.86. One pond determined to be negative for great crested newt by field survey was positive by eDNA analysis, revealing the potential for improved detection rates using this methodology. Analysis of water samples collected in late summer indicates that eDNA analysis could be used to detect great crested newt after the optimal survey window for current field techniques had passed. Consequently, eDNA analysis could augment currently stipulated techniques for great crested newt surveying as a relatively quick and inexpensive tool for collecting great crested newt presence and distribution data within the UK instead of or prior to full field surveys.
PMCID: PMC4242556  PMID: 25505530
Ecological survey; environmental DNA; great crested newt; real-time PCR; water samples
5.  Injectable and oral contraceptives and risk of HIV acquisition in women: an analysis of data from the MDP301 trial 
Human Reproduction (Oxford, England)  2014;29(8):1810-1817.
Do injectable and oral contraceptives increase the risk of human immunodeficiency virus (HIV) acquisition in women?
After adjusting for confounders, evidence of a significantly increased risk of HIV remained for women using injectable depo-medroxyprogesterone (DMPA) (hazard ratio = 1.49, 95% confidence interval (1.06–2.08)) but not for injectable norethisterone-enanthate (Net-En) or oral contraceptive pills (OC).
An association between the use of some types of hormonal contraception (HC) methods and an increased risk of HIV, possibly through changes in the genital tract environment and alterations in the immune response, has been previously observed, although not consistently. A recent systematic review of these studies has highlighted the need for more definitive evidence.
A secondary data analysis of the MDP301 phase 3 microbicide trial was conducted to estimate the effects of use of different methods of HC on the risk of HIV acquisition in women. HIV-negative women (n = 8663) with a median age of 28 years were included in the analysis; 382 HIV seroconverted by 52 weeks follow-up; 10% of women-years were lost to follow-up before 52 weeks.
Contraceptive use was reported at each 4-weekly visit. Cox proportional hazards (PH) models were used to estimate the effects of baseline and current use of injectable DMPA, injectable Net-En and OC compared with no HC, on the risk of HIV, adjusting for baseline and time-updated covariates. Causal effects for 52 weeks of HC use compared with no HC were estimated in a weighted Cox model, censoring women at deviation from baseline HC use (or non-use) or pregnancy.
At baseline, 2499 (29%) women were on DMPA, 1180 (14%) on Net-En, and 1410 (16%) on OC; 3574 (40%) not on HC, started HC in follow-up. Adjusted hazard ratios (HR) for baseline HC use, compared with no HC, were 1.38 (95% confidence interval (CI) 1.07–1.78) for DMPA; 1.18 (0.86–1.62) for Net-En and 0.97 (0.68–1.38) for OC. The estimated causal effects of DMPA and Net-En over 52 weeks were: HR = 1.49 (95% CI 1.06–2.08) and HR = 1.31 (95% CI 0.62–1.61), respectively.
A main limitation of the study was that it was a secondary analysis of data from a study that was not designed to investigate this question. Despite our best efforts, we cannot exclude residual confounding to explain the effect of DMPA.
The results of this study should be reviewed by the World Health Organization to determine whether current recommendations on the use of DMPA in settings with high HIV prevalence require modification.
MDP is a partnership of African and European academic/government institutions with commercial organizations, which is funded by the UK Government (DFID and MRC), with support from IPM and EDCTP. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: None.
PMCID: PMC4093991  PMID: 24838704
HIV; contraception; women; sexual behaviour
6.  Plasma Viral Loads During Early HIV-1 Infection Are Similar in Subtype C– and Non-Subtype C–Infected African Seroconverters 
The Journal of Infectious Diseases  2013;207(7):1166-1170.
Recent data suggest that infection with human immunodeficiency virus type 1 (HIV-1) subtype C results in prolonged high-level viremia (>5 log10 copies/mL) during early infection. We examined the relationship between HIV-1 subtype and plasma viremia among 153 African seroconverters. Mean setpoint viral loads were similar for C and non-C subtypes: 4.36 vs 4.42 log10 copies/mL (P = .61). The proportion of subtype C–infected participants with viral loads >5 log10 copies/mL was not greater than the proportion for those with non-C infection. Our data do not support the hypothesis that higher early viral load accounts for the rapid spread of HIV-1 subtype C in southern Africa.
PMCID: PMC3583276  PMID: 23315322
HIV-1; group M subtype; plasma viral load; early infection; Africa
7.  Contraceptive method and pregnancy incidence among African women in HIV-1 serodiscordant partnerships 
AIDS (London, England)  2012;26(4):513-518.
Effective contraception reduces unintended pregnancies and is a central strategy to reduce vertical HIV-1 transmission for HIV-1 infected women.
Among 2269 HIV-1 seropositive and 1085 seronegative women from 7 African countries who were members of HIV-1 serodiscordant heterosexual partnerships and who were participating in an HIV-1 prevention clinical trial, we assessed pregnancy incidence for women using various contraceptive methods using multivariate Andersen-Gill analysis.
Compared with women using no contraceptive method, pregnancy incidence was significantly reduced among HIV-1 seropositive and seronegative women using injectable contraception (adjusted hazard ratio (aHR) 0.24, p=0.001 and aHR 0.25, p<0.001, respectively). Oral contraceptives significantly reduced pregnancy risk only among HIV-1 seropositive women (aHR 0.51, p=0.004) but not seronegative women (aHR 0.64, p=0.3), and, for both seropositive and seronegative women, oral contraceptive pill users were more likely to become pregnant than injectable contraceptive users (aHR 2.22, p=0.01 for HIV-1 seropositive women and aHR 2.65, p=0.09 for HIV-1 seronegative women). Condoms, when reported as being used as the primary contraceptive method, marginally reduced pregnancy incidence (aHR 0.85, p=0.1 for seropositive women and aHR 0.67, p=0.02 for seronegative women). There were no pregnancies among women using intrauterine devices, implantable methods or who had undergone surgical sterilization, although these methods were used relatively infrequently.
Family planning programs and HIV-1 prevention trials need innovative ways to motivate uptake and sustained use of longer acting, less user-dependent contraception for women who do not desire pregnancy.
PMCID: PMC3932300  PMID: 22156966
HIV-1; serodiscordant couples; contraception; Africa; women
8.  Cost-effectiveness of tenofovir gel in urban South Africa: model projections of HIV impact and threshold product prices 
There is urgent need for effective HIV prevention methods that women can initiate. The CAPRISA 004 trial showed that a tenofovir-based vaginal microbicide had significant impact on HIV incidence among women. This study uses the trial findings to estimate the population-level impact of the gel on HIV and HSV-2 transmission, and price thresholds at which widespread product introduction would be as cost-effective as male circumcision in urban South Africa.
The estimated ‘per sex-act’ HIV and HSV-2 efficacies were imputed from CAPRISA 004. A dynamic HIV/STI transmission model, parameterised and fitted to Gauteng (HIV prevalence of 16.9% in 2008), South Africa, was used to estimate the impact of gel use over 15 years. Uptake was assumed to increase linearly to 30% over 10 years, with gel use in 72% of sex-acts. Full economic programme and averted HIV treatment costs were modelled. Cost per DALY averted is estimated and a microbicide price that equalises its cost-effectiveness to that of male circumcision is estimated.
Using plausible assumptions about product introduction, we predict that tenofovir gel use could lead to a 12.5% and 4.9% reduction in HIV and HSV-2 incidence respectively, by year 15. Microbicide introduction is predicted to be highly cost-effective (under $300 per DALY averted), though the dose price would need to be just $0.12 to be equally cost-effective as male circumcision. A single dose or highly effective (83% HIV efficacy per sex-act) regimen would allow for more realistic threshold prices ($0.25 and $0.33 per dose, respectively).
These findings show that an effective coitally-dependent microbicide could reduce HIV incidence by 12.5% in this setting, if current condom use is maintained. For microbicides to be in the range of the most cost-effective HIV prevention interventions, product costs will need to decrease substantially.
PMCID: PMC3899035  PMID: 24405719
HIV; Modelling; Cost-effectiveness; Microbicides; South Africa; Introduction of new technologies; Economic analysis; Tenofovir; ARV-based prevention; Pre-exposure prophylaxis (PreP)
9.  How Much Demand for New HIV Prevention Technologies Can We Really Expect? Results from a Discrete Choice Experiment in South Africa 
PLoS ONE  2013;8(12):e83193.
For the first time in the history of HIV, new bio-medical interventions have been shown to be effective in preventing HIV transmission. For these new HIV prevention technologies (NPTs) to have an impact on the epidemic, they must be widely used. This study uses a discrete choice experiment (DCE) to: understand the relative strength of women’s preferences for product characteristics, understand the implications for substitution away from male condoms, and inform realistic modelling of their potential impact and cost-effectiveness.
A DCE was conducted among 1017 women in urban South Africa. Women were presented with choices between potential women’s NPTs (microbicides, diaphragm, female condom) and ‘what I did last time’ (use or not use a condom) with different HIV and pregnancy prevention effectiveness’ and prices. Choice probabilities are estimated using the nested logit model and used to predict uptake.
In this high HIV prevalence setting, HIV prevention effectiveness is the main driver of uptake followed by pregnancy prevention effectiveness. For example a microbicide with poor effectiveness would have niche appeal at just 11% predicted uptake, while a highly effective microbicide (95% effective against HIV and pregnancy) would have far wider appeal (56% predicted uptake). Though women who reported not using condoms were more likely to choose the NPTs, at current very high rates of male condom use in South Africa (60%), about half of microbicide uptake is projected to be among those currently not using condoms.
Women are very interested in NPTs, especially if highly effective in preventing HIV and pregnancy. Women in greatest need were also most likely to switch to the new products. Where products are not yet available for distribution, proxy data, such as that generated by DCEs, can bring realism to overly optimistic uptake scenarios found in many current impact models.
PMCID: PMC3875434  PMID: 24386160
10.  Intersection of HIV and Reproductive Health 
AIDS Research and Treatment  2013;2013:418918.
PMCID: PMC3857734  PMID: 24349767
11.  Geographic Distribution of Human Immunodeficiency Virus in South Africa 
In common with most countries, little is know about the geographic distribution of human immunodeficiency virus (HIV) in South Africa. Variations in HIV infection of persons 15–24 years of age were modeled and mapped using generalized linear spatial models and Bayesian prediction based on data from a national HIV household survey conducted in 2003 and comprising 11,904 youth from approximately 700 enumeration areas that were randomly selected from the national census. The maps show considerable variation in HIV prevalence within provinces. The lowest levels were found in inland rural areas of the Western Cape, and the highest in northwestern parts of KwaZulu Natal, southern Mpumalanga, and eastern Free State. Prevalence of HIV was associated with ethnicity, urban status, and unemployment. Detailed maps of HIV prevalence can be effectively used in guiding and focusing intervention programs to areas of particular need.
PMCID: PMC3836237  PMID: 18165541
12.  Concurrent Sexual Partnerships and Human Immunodeficiency Virus Risk Among South African Youth 
Sexually transmitted diseases  2011;38(6):459-466.
To estimate the prevalence of concurrency (more than 1 sex partner overlapping in time), the attitudes/behaviors of those engaged in concurrency, length of relationship overlap, and the association between concurrency and human immunodeficiency virus (HIV) among South Africans aged 15 to 24 years.
A cross-sectional, nationally representative, household survey of HIV infection, and sexual attitudes and behaviors was conducted among 11,904 15 to 24 year old South Africans in 2003. Analyses were conducted among sexually experienced youth.
Men were more likely to report having concurrent (24.7%) than serial partners (5.7%) in the past 12 months, but concurrency was not associated with HIV. Among women, concurrency and serial monogamy were equally common (4.7%), and concurrency, defined by respondent reports of multiple ongoing partners, was associated with HIV in multivariate analysis (odds ratio, 3.4; 95% confidence interval, 1.8–6.5). Median length of relationship overlap was approximately 4 months for women and 3 months for men. Compared to serial monogamists, concurrents reported less consistent condom use, and female concurrents were more likely to report transactional sex and problems negotiating condoms and refusing intercourse.
Concurrency is a common partnership pattern among those youth with multiple partners, especially men. For women, having concurrent relationships may be associated with relationship power imbalances and less ability to protect against HIV. Given the prevalence and likely significance of concurrency in the spread of HIV throughout a sexual network, our findings underscore the need for prevention efforts targeting fidelity.
PMCID: PMC3763704  PMID: 21258268
13.  Hormonal contraceptive use and risk of HIV-1 disease progression 
AIDS (London, England)  2013;27(2):261-267.
For HIV-1 infected women, hormonal contraception prevents unintended pregnancy, excess maternal morbidity, and vertical HIV-1 transmission. Hormonal contraceptives are widely used but their effects on HIV-1 disease progression are unclear.
In a prospective study among 2269 chronically HIV-1 infected women from 7 countries in East and southern Africa and with enrollment CD4 counts ≥250 cells/mm3, we compared rates of HIV-1 disease progression among those using and not using hormonal contraception (i.e. oral or injectable methods). The primary outcome was a composite endpoint of CD4 decline to <200 cells/mm3, initiation of antiretroviral therapy, or death.
372 women experienced HIV-1 disease progression during 3242 years of follow up (incidence rate=11.5 events per 100 person-years). Rates of HIV-1 disease progression among women who were currently using and not using hormonal contraception were 8.54 and 12.31 per 100 person-years, respectively (adjusted hazard ratio [HR] 0.74, 95% CI 0.56–0.98, p=0.04). Rates were 8.58 and 8.39 per 100 person-years for the subsets using injectable and oral contraception (adjusted HR=0.72, p=0.04 for injectable users and adjusted HR=0.83, p=0.5 for oral users compared to women not using hormonal contraception). Sensitivity analyses assessing enrollment or cumulative contraceptive use during the study demonstrated risk estimates closer to 1.0 with no evidence for accelerated disease progression.
Among African women with chronic HIV-1 infection, use of hormonal contraception was not associated with deleterious consequences for HIV-1 disease progression.
PMCID: PMC3740957  PMID: 23079806
HIV-1; women; hormonal contraception; death; CD4 count; antiretroviral therapy
14.  Using HPV vaccination for promotion of an adolescent package of care: opportunity and perspectives 
BMC Public Health  2013;13:493.
Adolescents are a difficult population to access for preventive health care, particularly in less resourced countries. Evidence from developed countries indicates that the HPV vaccine schedule may be a useful platform from which to deliver other adolescent health care services. We conducted a qualitative cross sectional study to assess the potential for using the HPV vaccine in the South African public health care system as an opportunity for integrated health care services for adolescents.
Parents, young adolescents, community members and key informants participated in interviews and focus group discussions about feasibility and acceptability, particularly the use of the HPV vaccination as the basis for an integrated adolescent package of care. Health care providers in both provinces participated in focus group discussions and completed a pairwise ranking exercise to compare and prioritise interventions for inclusion in an adolescent package of care.
Participants were in favour of integration and showed preference for detailed information about the HPV vaccine, general health information and specific sexual and reproductive health information. Among health care workers, results differed markedly by location. In North West, prioritisation was given to information, screening and referral for tobacco and alcohol abuse, and screening for hearing and vision. In Gauteng integration with referral for male circumcision, and information, screening and referral for child abuse were ranked most highly.
There is generally support for the delivery of adolescent preventive health services. Despite national priorities to address adolescent health needs, our data suggest that national policies might not always be appropriate for vastly different local situations. While decisions about interventions to include have traditionally been made at country level, our results suggest that local context needs to be taken account of. We suggest low resource strategies for ensuring that national policies are introduced at local level in a manner that addresses local priorities, context and resource availability.
PMCID: PMC3681713  PMID: 23692596
15.  Hormonal contraceptive use and risk of HIV-1 transmission: a prospective cohort analysis 
The Lancet Infectious Diseases  2011;12(1):19-26.
Hormonal contraceptives are used widely but their effects on HIV-1 risk are unclear.
We followed 3790 heterosexual HIV-1 serodiscordant couples from seven African countries participating in two longitudinal HIV-1 incidence studies. Among hormonal contraceptive users (including injectable and oral contraceptive users) and nonusers, we compared rates of HIV-1 acquisition in women and HIV-1 transmission from women to men.
Among 1314 couples in which the HIV-1 seronegative partner was female, HIV-1 acquisition rates were 6.61 and 3.78 per 100 person-years among hormonal contraceptive users and nonusers (adjusted hazard ratio [AHR]=1.98, 95% confidence interval [CI] 1.06–3.68, p=0.03). Among 2476 couples in which the HIV-1 seronegative partner was male, HIV-1 transmission rates from women to men were 2.61 and 1.51 per 100 person-years in those whose partners currently used versus did not use hormonal contraception (AHR=1.97, 95% CI 1.12–3.45, p=0.02). In subgroup analysis, injectable contraceptive users had increased risk for acquiring and transmitting HIV-1 to their partner and HIV-1 seropositive women using injectable contraception had higher genital HIV-1 RNA concentrations, suggesting a mechanism for increased transmission risk. Oral contraceptives were used too infrequently to draw definitive conclusions about HIV-1 risk.
Women should be counseled about potentially increased risk of HIV-1 acquisition and transmission with hormonal contraception, particularly injectable methods, and about the importance of dual protection with condoms to decrease HIV-1 risk. Non-hormonal or lower-dose hormonal contraceptive methods should be considered for women with or at-risk for HIV-1.
National Institutes of Health (R03 HD068143, R01 AI083034, P30 AI027757, and T32 AI007140) and the Bill and Melinda Gates Foundation (26469 and 41185).
PMCID: PMC3266951  PMID: 21975269
HIV-1; serodiscordant couples; Africa; hormonal contraception
16.  Continued High Risk Sexual Behavior Following Diagnosis with Acute HIV Infection in South Africa and Malawi: Implications for Prevention 
AIDS and behavior  2011;15(6):1243-1250.
Understanding sexual behavior following diagnosis of acute HIV infection (AHI) is key to developing prevention programs targeting individuals diagnosed with AHI. We conducted separate qualitative and quantitative interviews with individuals newly diagnosed (n = 19) with AHI at 1-, 4- and 12-weeks post-diagnosis and one qualitative interview with individuals who had previously been diagnosed with AHI (n = 18) in Lilongwe, Malawi and Johannesburg, South Africa between October 2007 and June 2008. The majority of participants reported engaging in sexual activity following diagnosis with AHI with a significant minority reporting unprotected sex during this time. Most participants perceived to have changed their behavior following diagnosis. However, participants reported barriers to condom use and abstinence, in particular, long term relationships and the need for disclosure of sero-status. Understanding of increased infectiousness during AHI was limited. Participants reported a desire for a behavioral intervention at the time of AHI diagnosis, however, there were differences by country in the types of interventions participants found acceptable. Studies are underway to determine the feasibility, acceptability and potential effectiveness of interventions designed for individuals with AHI.
PMCID: PMC3530889  PMID: 20978833
HIV; Africa; Sexual behavior; Condom use
17.  Sexual Violence and Reproductive Health Outcomes Among South African Female Youths: A Contextual Analysis 
American journal of public health  2009;99(Suppl 2):S425-S431.
We studied whether female youths from communities with higher sexual violence were at greater risk of negative reproductive health outcomes.
We used data from a 2003 nationally representative household survey of youths aged 15–24 years in South Africa. The key independent variable was whether a woman had ever been threatened or forced to have sex. We aggregated this variable to the community level to determine, with control for individual-level experience with violence, whether the community-level prevalence of violence was associated with HIV status and adolescent pregnancy among female, sexually experienced, never-married youths.
Youths from communities with greater sexual violence were significantly more likely to have experienced an adolescent pregnancy or to be HIV-positive than were youths from communities experiencing lower sexual violence. Youths from communities with greater community-level violence were also less likely to have used a condom at their last sexual encounter. Individual-level violence was only associated with condom nonuse.
Programs to reduce adolescent pregnancies and HIV risk in South Africa and elsewhere in sub-Saharan Africa must address sexual violence as part of effective prevention strategies. (Am J Public Health. 2009;99:S425–S431. doi: 10.2105/AJPH.2008.136606)
PMCID: PMC3515795  PMID: 19372525
18.  A tale of two countries: Rethinking sexual risk for HIV among young people in South Africa and the United States 
To compare the sexual behaviors of young people in South Africa (SA) and the United States (US) with the aim of better understanding the potential role of sexual behavior in HIV transmission in two countries with strikingly different HIV epidemics.
Nationally representative, population-based surveys of young people ages 18-24 from SA (n=7,548) and the US (n=13,451) were used.
The prevalence of HIV was 10.2% in SA and <1% in the US. Young women and men in the US reported an earlier age of first sex than those in SA (mean age of coital debut for females: US (16.5), SA (17.4); for males: US (16.4), SA (16.7)). The median number of lifetime partners is higher in the US than in SA: Females: US (4), SA (2); Males US (4), SA (3). Reported condom use at last sex is lower in the US than SA: Females: US (36.1%), SA (45.4%); Males: US (48%), SA (58%). On average, SA young women report greater age differences with their sex partners than young women in the US.
Young people in the US report riskier sexual behaviors than young people in SA, despite the much higher prevalence of HIV infection in South Africa. Factors above and beyond sexual behavior likely play a key role in the ongoing transmission of HIV in South African youth, and must be urgently uncovered to develop maximally effective prevention strategies.
PMCID: PMC3159866  PMID: 21856514
19.  The Oral Secretion of Infectious Scrapie Prions Occurs in Preclinical Sheep with a Range of PRNP Genotypes 
Journal of Virology  2012;86(1):566-571.
Preclinical sheep with the highly scrapie-susceptible VRQ/VRQ PRNP genotype secrete prions from the oral cavity. In order to further understand the significance of orally available prions, buccal swabs were taken from sheep with a range of PRNP genotypes and analyzed by serial protein misfolding cyclic amplification (sPMCA). Prions were detected in buccal swabs from scrapie-exposed sheep of genotypes linked to high (VRQ/VRQ and ARQ/VRQ) and low (ARR/VRQ and AHQ/VRQ) lymphoreticular system involvement in scrapie pathogenesis. For both groups, the level of prion detection was significantly higher than that for scrapie-resistant ARR/ARR sheep which were kept in the same farm environment and acted as sentinel controls for prions derived from the environment which might contaminate the oral cavity. In addition, sheep with no exposure to the scrapie agent did not contain any measurable prions within the oral cavity. Furthermore, prions were detected in sheep over a wide age range representing various stages of preclinical disease. These data demonstrate that orally available scrapie prions may be a common feature in sheep incubating scrapie, regardless of the PRNP genotype and any associated high-level accumulation of PrPSc within lymphoreticular tissues. PrPSc was present in buccal swabs from a large proportion of sheep with PRNP genotypes associated with relatively low disease penetrance, indicating that subclinical scrapie infection is likely to be a common occurrence. The significance of positive sPMCA reactions was confirmed by the transmission of infectivity in buccal swab extracts to Tg338 mice, illustrating the likely importance of orally available prions in the horizontal transmission of scrapie.
PMCID: PMC3255911  PMID: 22013047
20.  Efavirenz Conceptions and Regimen Management in a Prospective Cohort of Women on Antiretroviral Therapy 
Use of the antiretroviral drug efavirenz (EFV) is not recommended by the WHO or South African HIV treatment guidelines during the first trimester of pregnancy due to potential fetal teratogenicity; there is little evidence of how clinicians manage EFV-related fertility concerns. Women on antiretroviral therapy (ART) were enrolled into a prospective cohort in four public clinics in Johannesburg, South Africa. Fertility intentions, ART regimens, and pregnancy testing were routinely assessed during visits. Women reporting that they were trying to conceive while on EFV were referred for regimen changes. Kaplan-Meier estimators were used to assess incidence across ART regimens. From the 822 women with followup visits between August 2009–March 2011, 170 pregnancies were detected during study followup, including 56 EFV conceptions. Pregnancy incidence rates were comparable across EFV, nevirapine, and lopinavir/ritonavir person-years (95% 100/users (P = 0.25)); incidence rates on EFV were 18.6 Confidence Interval: 14.2–24.2). Treatment substitution from EFV was made for 57 women, due to pregnancy intentions or actual pregnancy; however, regimen changes were not systematically applied across women. High rates of pregnancy on EFV and inconsistencies in treatment management suggest that clearer guidelines are needed regarding how to manage fertility-related issues in. women on EFV-based regimens.
PMCID: PMC3384948  PMID: 22778534
21.  High Incidence of Unplanned Pregnancy after Antiretroviral Therapy Initiation: Findings from a Prospective Cohort Study in South Africa 
PLoS ONE  2012;7(4):e36039.
Increased fertility rates in HIV-infected women receiving antiretroviral therapy (ART) have been attributed to improved immunological function; it is unknown to what extent the rise in pregnancy rates is due to unintended pregnancies.
Non-pregnant women ages 18–35 from four public-sector ART clinics in Johannesburg, South Africa, were enrolled into a prospective cohort and followed from August 2009–March 2011. Fertility intentions, contraception and pregnancy status were measured longitudinally at participants' routine ART clinic visits.
Of the 850 women enrolled, 822 (97%) had at least one follow-up visit and contributed 745.2 person-years (PY) at-risk for incident pregnancy. Overall, 170 pregnancies were detected in 161 women (incidence rate [IR]: 21.6/100 PY [95% confidence interval (CI): 18.5–25.2]). Of the 170 pregnancies, 105 (62%) were unplanned. Unmet need for contraception was 50% higher in women initiating ART in the past year as compared to women on ART>1 year (prevalence ratio 1.5 [95% CI: 1.1–2.0]); by two years post-ART initiation, nearly one quarter of women had at least one unplanned pregnancy. Cumulative incidence of pregnancy was equally high among recent ART initiators and ART experienced participants: 23.9% [95% CI: 16.4–34.1], 15.9% [12.0–20.8], and 21.0% [16.8–26.1] for women on ART 0–1 yr, >1 yr–2 yrs, and >2 yrs respectively (log-rank, p = 0.54). Eight hormonal contraceptive failures were detected [IR: 4.4 [95% CI: 2.2–8.9], 7/8 among women using injectable methods. Overall 47% (80/170) of pregnancies were not carried to term.
Rates of unintended pregnancies among women on ART are high, including women recently initiating ART with lower CD4 counts and higher viral loads. A substantial burden of pregnancy loss was observed. Integration of contraceptive services and counselling into ART care is necessary to reduce maternal and child health risks related to mistimed and unwanted pregnancies. Further research into injectable contraceptive failures on ART is warranted.
PMCID: PMC3338622  PMID: 22558319
22.  Optimal Uses of Antiretrovirals for Prevention in HIV-1 Serodiscordant Heterosexual Couples in South Africa: A Modelling Study 
PLoS Medicine  2011;8(11):e1001123.
Hallett et al use a mathematical model to examine the long-term impact and cost-effectiveness of different pre-exposure prophylaxis (PrEP) strategies for HIV prevention in serodiscordant couples.
Antiretrovirals have substantial promise for HIV-1 prevention, either as antiretroviral treatment (ART) for HIV-1–infected persons to reduce infectiousness, or as pre-exposure prophylaxis (PrEP) for HIV-1–uninfected persons to reduce the possibility of infection with HIV-1. HIV-1 serodiscordant couples in long-term partnerships (one member is infected and the other is uninfected) are a priority for prevention interventions. Earlier ART and PrEP might both reduce HIV-1 transmission in this group, but the merits and synergies of these different approaches have not been analyzed.
Methods and Findings
We constructed a mathematical model to examine the impact and cost-effectiveness of different strategies, including earlier initiation of ART and/or PrEP, for HIV-1 prevention for serodiscordant couples. Although the cost of PrEP is high, the cost per infection averted is significantly offset by future savings in lifelong treatment, especially among couples with multiple partners, low condom use, and a high risk of transmission. In some situations, highly effective PrEP could be cost-saving overall. To keep couples alive and without a new infection, providing PrEP to the uninfected partner could be at least as cost-effective as initiating ART earlier in the infected partner, if the annual cost of PrEP is <40% of the annual cost of ART and PrEP is >70% effective.
Strategic use of PrEP and ART could substantially and cost-effectively reduce HIV-1 transmission in HIV-1 serodiscordant couples. New and forthcoming data on the efficacy of PrEP, the cost of delivery of ART and PrEP, and couples behaviours and preferences will be critical for optimizing the use of antiretrovirals for HIV-1 prevention.
Please see later in the article for the Editors' Summary
Editors' Summary
Every year, about 2.5 million people become infected with HIV, the virus that causes AIDS. HIV is usually transmitted through unprotected sex with an HIV-infected partner. It destroys immune system cells (including CD4 cells, a type of lymphocyte), leaving infected individuals susceptible to other infections. There is no cure for AIDS, although HIV can be held in check with antiretroviral therapy (ART), and there is no vaccine that protects against HIV infection. So, to halt the AIDS epidemic, other ways of preventing the spread of HIV are needed. Antiretroviral drugs could potentially be used in two ways to reduce HIV transmission. First, ART could be given to HIV-infected people before they need it for their own health to reduce their infectiousness; the World Health Organization currently recommends that HIV-positive people initiate ART when their CD4 count drops below 350 cells/µl blood but in many African countries ART is only initiated when CD4 counts fall below 200 cells/µl. Second, ART could be given to HIV-uninfected people to reduce acquisition of the virus. This approach—preexposure prophylaxis (PrEP)—has provided protection against HIV transmission in some but not all clinical trials.
Why Was This Study Done?
Couples in long-term relationships where one partner is HIV-positive and the other is HIV-negative (HIV serodiscordant couples) are a priority group for prevention interventions. In sub-Saharan Africa, where most new HIV infections occur, 10%–20% of stable partnerships are serodiscordant and condom use is often low, not least because such couples may want children. Earlier ART or PrEP might reduce HIV transmission in this group but the merits of different approaches have not been analyzed. In this study, the researchers use a mathematical model to examine the long-term impact and cost-effectiveness of different PrEP and ART strategies for HIV prevention in serodiscordant couples.
What Did the Researchers Do and Find?
The researchers constructed a model to simulate HIV infection and disease progression among hypothetical HIV serodiscordant stable heterosexual couples. The model incorporated data from South Africa on couple characteristics, disease progression, ART use, pregnancies, frequency of sex, and contact with other sexual partners, as well as estimates of the effectiveness of PrEP from clinical trials. The researchers used the model to compare the impact on HIV transmission, survival and quality of life, and the cost-effectiveness of no PrEP with four PrEP strategies—always use PrEP after diagnosis of HIV serodiscordancy, use PrEP up to and for a year after ART initiation by the HIV-infected partner (at a CD4 count of ≤200 cells/µl or ≤350 cells/µl), use PrEP only up to ART initiation by the infected partner, and use PrEP only while trying for a baby and during pregnancy. The model predicts, for example, that the cost per infection averted of PrEP used before ART initiation will be offset by future savings in lifelong treatment, particularly among couples with multiple partners, low condom use, and a high risk of transmission. To keep couples alive without the HIV-uninfected partner becoming infected, it could be more cost-effective to provide PrEP to the uninfected partner than to initiate ART earlier in the infected partner, provided the annual cost of PrEP is less than 40% of the annual cost of ART and PrEP is more than 70% effective. Finally, if PREP is 30%–60% effective, the most cost-effective strategy for couples could be to use PrEP in the uninfected partner prior to ART initiation in the infected partner at a CD4 count ≤350 cells/µl.
What Do These Findings Mean?
These findings suggest that the strategic use of PrEP and ART could cost-effectively reduce HIV transmission in HIV serodiscordant stable heterosexual couples in sub-Saharan Africa. The accuracy of these findings depends on the assumptions included in the mathematical model and on the data fed into it. In particular, the interpretation of these results is complicated by uncertainties in the likely cost of PrEP and the “real-world” effectiveness of PrEP. Nevertheless, these findings suggest that PrEP may become a valuable addition in some settings to existing approaches for HIV prevention such as condom promotion and male circumcision programs. Moreover, additional simulations with this mathematical model using more accurate information on the costs and effectiveness of PrEP could assist in future policy making decisions.
Additional Information
Please access these Web sites via the online version of this summary at
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, summaries of recent research findings on HIV care and treatment, and a section on PrEP
Information is available from Avert, an international AIDS charity on many aspects of HIV/AIDS, including information on all aspects of HIV prevention, and on HIV/AIDS in Africa (in English and Spanish)
AVAC Global Advocacy for HIV Prevention provides up-to-date information on all aspects of HIV prevention, including PrEP
The US Centers for Disease Control and Prevention also has information on PrEP
WHO provides information about antiretroviral therapy
Patient stories about living with HIV/AIDS are available through Avert and through the charity website Healthtalkonline
PMCID: PMC3217021  PMID: 22110407
23.  Increased Risk of HIV-1 Transmission in Pregnancy: A Prospective Study among African HIV-1 Serodiscordant Couples 
AIDS (London, England)  2011;25(15):1887-1895.
Physiologic and behavioral changes during pregnancy may alter HIV-1 susceptibility and infectiousness. Prospective studies exploring pregnancy and HIV-1 acquisition risk in women have found inconsistent results. No study has explored the effect of pregnancy on HIV-1 transmission risk from HIV-1 infected women to male partners.
In a prospective study of African HIV-1 serodiscordant couples, we evaluated the relationship between pregnancy and the risk of 1) HIV-1 acquisition among women and 2) HIV-1 transmission from women to men.
3321 HIV-1 serodiscordant couples were enrolled, 1085 (32.7%) with HIV-1 susceptible female partners and 2236 (67.3%) with susceptible male partners. HIV-1 incidence in women was 7.35 versus 3.01 per 100 person-years during pregnant and non-pregnant periods (hazard ratio [HR] 2.34, 95% confidence interval [CI] 1.33–4.09). This effect was attenuated and not statistically significant after adjusting for sexual behavior and other confounding factors (adjusted HR 1.71, 95% CI 0.93–3.12). HIV-1 incidence in male partners of infected women was 3.46 versus 1.58 per 100 person-years when their partners were pregnant versus not pregnant (HR 2.31, 95% CI 1.22–4.39). This effect was not attenuated in adjusted analysis (adjusted HR 2.47, 95% CI 1.26–4.85).
HIV-1 risk increased two-fold during pregnancy. Elevated risk of HIV-1 acquisition in pregnant women appeared in part to be explained by behavioral and other factors. This is the first study to show pregnancy increased the risk of female-to-male HIV-1 transmission, which may reflect biological changes of pregnancy that could increase HIV-1 infectiousness.
PMCID: PMC3173565  PMID: 21785321
pregnancy; HIV-1 transmission; Africa; heterosexual; serodiscordant
24.  Birth outcomes in South African women receiving highly active antiretroviral therapy: a retrospective observational study 
Use of highly active antiretroviral therapy (HAART), a triple-drug combination, in HIV-infected pregnant women markedly reduces mother to child transmission of HIV and decreases maternal morbidity. However, there remains uncertainty about the effects of in utero exposure to HAART on foetal development.
Our objectives were to investigate whether in utero exposure to HAART is associated with low birth weight and/or preterm birth in a population of South African women with advanced HIV disease. A retrospective observational study was performed on women with CD4 counts ≤250 cells/mm3 attending antenatal antiretroviral clinics in Johannesburg between October 2004 and March 2007. Low birth weight (<2.5 kg) and preterm birth rates (<37 weeks) were compared between those exposed and unexposed to HAART during pregnancy. Effects of different HAART regimen and duration were assessed.
Among HAART-unexposed infants, 27% (60/224) were low birth weight compared with 23% (90/388) of early HAART-exposed (exposed <28 weeks gestation) and 19% (76/407) of late HAART-exposed (exposed ≥28 weeks) infants (p = 0.05). In the early HAART group, a higher CD4 cell count was protective against low birth weight (AOR 0.57 per 50 cells/mm3 increase, 95% CI 0.45-0.71, p < 0.001) and preterm birth (AOR 0.68 per 50 cells/mm3 increase, 95% CI 0.55-0.85, p = 0.001). HAART exposure was associated with an increased preterm birth rate (15%, or 138 of 946, versus 5%, or seven of 147, in unexposed infants, p = 0.001), with early nevirapine and efavirenz-based regimens having the strongest associations with preterm birth (AOR 5.4, 95% CI 2.1-13.7, p < 0.001, and AOR 5.6, 95% CI 2.1-15.2, p = 0.001, respectively).
In this immunocompromised cohort, in utero HAART exposure was not associated with low birth weight. An association between NNRTI-based HAART and preterm birth was detected, but residual confounding is plausible. More advanced immunosuppression was a risk factor for low birth weight and preterm birth, highlighting the importance of earlier HAART initiation in women to optimize maternal health and improve infant outcomes.
PMCID: PMC3163172  PMID: 21843356
25.  Investing in the future: lessons learnt from communicating the results of HSV/ HIV intervention trials in South Africa 
Communicating the results of randomised controlled trials may present challenges for researchers who have to work with communities and policy-makers to anticipate positive outcomes, while being aware that results may show no effect or harm.
We present a case study from the perspective of researchers in South Africa about the lessons learnt from communicating the results of four trials evaluating treatment for herpes simplex virus type 2 (HSV-2) as a new strategy for HIV prevention.
We show that contextual factors such as misunderstandings and mistrust played an important role in defining the communications response. Use of different approaches in combination was found to be most effective in building understanding, credibility and trust in the research process. During the communication process, researchers acted beyond their traditional role of neutral observers and became agents of social change. This change in role is in keeping with a global trend towards increased communication of research results and presents both opportunities and challenges for the conduct of future research.
Despite disappointing trial results which showed no benefit of HSV-2 treatment for HIV prevention, important lessons were learnt about the value of the communication process in building trust between researchers, community members and policy-makers, and creating an enabling environment for future research partnerships.
PMCID: PMC3121139  PMID: 21679389

Results 1-25 (43)