The epidemiology of human immunodeficiency virus in South Africa

We review the epidemiology of human immunodeficiency virus (HIV) in South Africa where the prevalence of HIV infection is among the highest in the world. The epidemic reached South Africa relatively recently but the prevalence of infection has increased rapidly and there are significant differences among provinces. Although few 15-year-old people are infected the prevalence increases rapidly with age thereafter, especially among women. The prevalence of herpes simplex virus type 2 exceeds that of HIV and curable sexually transmitted infections are common. 'Circular migration' may help to explain the high rates and rapid spread of HIV in the region. The incidence of tuberculosis has increased dramatically as a result of the HIV epidemic. Antiretroviral therapy for the prevention of vertical transmission has been shown to be effective in local conditions but transmission through breast-feeding remains problematical. While some epidemiological models have been developed, much more needs to be done in this regard in order to plan, coordinate and evaluate an effective response to the epidemic. We conclude by discussing some of the research that is needed and steps that could be taken to reduce the continued spread of the infection.     

Mother-to-child transmission of HIV-1 in sub-Saharan Africa: past, present and future challenges

HIV prevalence continues to be high among women of reproductive age in sub-Saharan Africa. In 2007 the HIV prevalence among pregnant women attending antenatal clinics was >20% in the southern African counties of Botswana, Swaziland, South Africa and Lesotho. Mother-to-child transmission (MTCT) of HIV can occur in-utero, intrapartum or postnatally. Without any preventive measure the overall rate of the MTCT of HIV in breastfeeding women could be 25-45%. Prior to the discovery of successful antiretroviral interventions to prevent the MTCT of HIV in sub-Saharan Africa (before 1999), innovative research determined the magnitude of the problem, the impact of the HIV epidemic on mothers and children, and the main risk factors associated with MTCT. Non-antiretroviral interventions conducted before 1999 such as washing the birth canal with antiseptics and antenatal supplementation with vitamin A did not reduce the MTCT of HIV. However, during the period 1999 to present, major successes were made in the prevention of the MTCT of HIV. The use of single-dose nevirapine prophylaxis to the mother and infant reduced the MTCT of HIV to ~12%. Subsequently, longer prophylaxis and combined antiretroviral regimens were shown to be highly effective and very low HIV transmission rates comparable to those in developed countries were reported in some clinical trial settings in sub-Saharan Africa. The future is promising but challenges remain. The current successful intervention modalities are entirely dependent on antiretrovirals and breastfeeding continues to be vital for the survival of the child in the African setting. Reviewing past and present achievements assists in focusing future research and development of prevention programs.     

Modelling HIV/AIDS in the presence of an HIV testing and screening campaign

Preventing and managing the HIV/AIDS epidemic in South Africa will dominate the next decade and beyond. Reduction of new HIV infections by implementing a comprehensive national HIV prevention programme at a sufficient scale to have real impact remains a priority. In this paper, a deterministic HIV/AIDS model that incorporates condom use, screening through HIV counseling and testing (HCT), regular testing and treatment as control strategies is proposed with the objective of quantifying the effectiveness of HCT in preventing new infections and predicting the long-term dynamics of the epidemic. It is found that a backward bifurcation occurs if the rate of screening is below a certain threshold, suggesting that the classical requirement for the basic reproduction number to be below unity though necessary, is not sufficient for disease control in this case. The global stabilities of the equilibria under certain conditions are determined in terms of the model reproduction number R₀. Numerical simulations are performed and the model is fitted to data on HIV prevalence in South Africa. The effects of changes in some key epidemiological parameters are investigated. Projections are made to predict the long-term dynamics of the disease. The epidemiological implications of such projections on public health planning and management are discussed.     

Theory versus data: how to calculate R0?

To predict the potential severity of outbreaks of infectious diseases such as SARS, HIV, TB and smallpox, a summary parameter, the basic reproduction number R(0), is generally calculated from a population-level model. R(0) specifies the average number of secondary infections caused by one infected individual during his/her entire infectious period at the start of an outbreak. R(0) is used to assess the severity of the outbreak, as well as the strength of the medical and/or behavioral interventions necessary for control. Conventionally, it is assumed that if R(0)>1 the outbreak generates an epidemic, and if R(0)<1 the outbreak becomes extinct. Here, we use computational and analytical methods to calculate the average number of secondary infections and to show that it does not necessarily represent an epidemic threshold parameter (as it has been generally assumed). Previously we have constructed a new type of individual-level model (ILM) and linked it with a population-level model. Our ILM generates the same temporal incidence and prevalence patterns as the population-level model; we use our ILM to directly calculate the average number of secondary infections (i.e., R(0)). Surprisingly, we find that this value of R(0) calculated from the ILM is very different from the epidemic threshold calculated from the population-level model. This occurs because many different individual-level processes can generate the same incidence and prevalence patterns. We show that obtaining R(0) from empirical contact tracing data collected by epidemiologists and using this R(0) as a threshold parameter for a population-level model could produce extremely misleading estimates of the infectiousness of the pathogen, the severity of an outbreak, and the strength of the medical and/or behavioral interventions necessary for control.     

Indices to Measure Risk of HIV Acquisition in Rakai,Uganda

Introduction

Targeting most-at-risk individuals with HIV preventive interventions is cost-effective. We developed gender-specific indices to measure risk of HIV among sexually active individuals in Rakai, Uganda.

Methods

We used multivariable Cox proportional hazards models to estimate time-to-HIV infection associated with candidate predictors. Reduced models were determined using backward selection procedures with Akaike''s information criterion (AIC) as the stopping rule. Model discrimination was determined using Harrell''s concordance index (c index). Model calibration was determined graphically. Nomograms were used to present the final prediction models.

Results

We used samples of 7,497 women and 5,783 men. 342 new infections occurred among females (incidence 1.11/100 person years,) and 225 among the males (incidence 1.00/100 person years). The final model for men included age, education, circumcision status, number of sexual partners, genital ulcer disease symptoms, alcohol use before sex, partner in high risk employment, community type, being unaware of a partner''s HIV status and community HIV prevalence. The Model''s optimism-corrected c index was 69.1 percent (95% CI = 0.66, 0.73). The final women''s model included age, marital status, education, number of sex partners, new sex partner, alcohol consumption by self or partner before sex, concurrent sexual partners, being employed in a high-risk occupation, having genital ulcer disease symptoms, community HIV prevalence, and perceiving oneself or partner to be exposed to HIV. The models optimism-corrected c index was 0.67 (95% CI = 0.64, 0.70). Both models were well calibrated.

Conclusion

These indices were discriminative and well calibrated. This provides proof-of-concept that population-based HIV risk indices can be developed. Further research to validate these indices for other populations is needed.     

High Incidence Is Not High Exposure: What Proportion of Prevention Trial Participants Are Exposed to HIV?

Objective

Randomized clinical trials of HIV prevention in high-risk populations of women often assume that all participants have similar exposure to HIV. However, a substantial fraction of women enrolled in the trial may have no or low exposure to HIV. Our objective was to estimate the proportion of women exposed to HIV throughout a hypothetical high-risk study population.

Methods

A stochastic individual-based model was developed to simulate the sexual behavior and the risk of HIV acquisition for a cohort of sexually active HIV-uninfected women in high HIV prevalence settings. Key behavior and epidemic assumptions in the model were based on published studies on HIV transmission in South Africa. The prevalence of exposure, defined as the proportion of women who have sex with HIV-infected partner, and HIV incidence were evaluated.

Results

Our model projects that in communities with HIV incidence rate of 1 per 100 person years, only 5-6% of women are exposed to HIV annually while in communities with an HIV incidence of 5 per 100 person years 20-25% of women are exposed to HIV. Approximately 70% of the new infections are acquired from partners with asymptomatic HIV.

Conclusions

Mathematical models suggest that a high proportion of women enrolled in HIV prevention trials may be unexposed to HIV even when incidence rates are high. The relationship between HIV exposure and other risk factors should be carefully analyzed when future clinical trials are planned.     

Combination HIV Prevention among MSM in South Africa: Results from Agent-based Modeling

HIV prevention trials have demonstrated the effectiveness of a number of behavioral and biomedical interventions. HIV prevention packages are combinations of interventions and offer potential to significantly increase the effectiveness of any single intervention. Estimates of the effectiveness of prevention packages are important for guiding the development of prevention strategies and for characterizing effect sizes before embarking on large scale trials. Unfortunately, most research to date has focused on testing single interventions rather than HIV prevention packages. Here we report the results from agent-based modeling of the effectiveness of HIV prevention packages for men who have sex with men (MSM) in South Africa. We consider packages consisting of four components: antiretroviral therapy for HIV infected persons with CD4 count <350; PrEP for high risk uninfected persons; behavioral interventions to reduce rates of unprotected anal intercourse (UAI); and campaigns to increase HIV testing. We considered 163 HIV prevention packages corresponding to different intensity levels of the four components. We performed 2252 simulation runs of our agent-based model to evaluate those packages. We found that a four component package consisting of a 15% reduction in the rate of UAI, 50% PrEP coverage of high risk uninfected persons, 50% reduction in persons who never test for HIV, and 50% ART coverage over and above persons already receiving ART at baseline, could prevent 33.9% of infections over 5 years (95% confidence interval, 31.5, 36.3). The package components with the largest incremental prevention effects were UAI reduction and PrEP coverage. The impact of increased HIV testing was magnified in the presence of PrEP. We find that HIV prevention packages that include both behavioral and biomedical components can in combination prevent significant numbers of infections with levels of coverage, acceptance and adherence that are potentially achievable among MSM in South Africa.     

Development,Calibration, and Validation of a U.S. White Male Population-Based Simulation Model of Esophageal Adenocarcinoma

Background

The incidence of esophageal adenocarcinoma (EAC) has risen rapidly in the U.S. and western world. The aim of the study was to begin the investigation of this rapid rise by developing, calibrating, and validating a mathematical disease simulation model of EAC using available epidemiologic data.

Methods

The model represents the natural history of EAC, including the essential biologic health states from normal mucosa to detected cancer. Progression rates between health states were estimated via calibration, which identified distinct parameter sets producing model outputs that fit epidemiologic data; specifically, the prevalence of pre-cancerous lesions and EAC cancer incidence from the published literature and Surveillance, Epidemiology, and End Results (SEER) data. As an illustrative example of a clinical and policy application, the calibrated and validated model retrospectively analyzed the potential benefit of an aspirin chemoprevention program.

Results

Model outcomes approximated calibration targets; results of the model''s fit and validation are presented. Approximately 7,000 cases of EAC could have been prevented over a 30-year period if all white males started aspirin chemoprevention at age 40 in 1965.

Conclusions

The model serves as the foundation for future analyses to determine a cost-effective screening and management strategy to prevent EAC morbidity and mortality.     

Assessing the Potential Impact of Hormonal-Based Contraceptives on HIV Transmission Dynamics Among Heterosexuals

HIV susceptibility linked to hormonal contraception (HC) has been studied before, but with mixed results. Reports from some of the recent findings have prompted the World Health Organisation to encourage women who use HC to concurrently use condoms in order to prevent HIV infection in the light of possible increased HIV risk of infection associated with hormone-based contraceptives. A two-sex HIV model classifying women into three risk groups consisting of individuals who use condoms, natural methods, and hormone-based contraceptives is formulated and analysed to assess the possible effects of various birth control strategies on the transmission dynamics of the disease. Our model results showed that women who use HC could be key drivers of the epidemic and that their increased infectivity may be critical in driving the epidemic. Women who use hormone-based contraceptives potentially act as a core group from which men get infected and in turn transmit the disease to other population groups. We fitted the model to HIV prevalence data for Zimbabwe reported by UNAIDS and Zimbabwe Ministry of Health and Child Care and used the model fit to project HIV prevalence. Predictions using HIV data for Zimbabwe suggest that a hypothesised increase in susceptibility and infectivity of two-, three-, and fourfold would result in a 25, 50, and 100% increase in baseline HIV prevalence projection, respectively, thus suggesting possible increased disease burden even in countries reporting plausible HIV prevalence declines. Although a possible causal relationship between HIV susceptibility and HC use remains subject of continuing scientific probe, its inclusion as part of birth control strategy has been shown in this study, to possibly increase HIV transmission. If proven, HC use may potentially explain the inordinate spread of HIV within the sub-Saharan Africa region and therefore compel for urgent assessment with a view to reorienting birth control methods in use in settings with generalised epidemics.     

Effectiveness of Integrated HIV Prevention Interventions among Chinese Men Who Have Sex with Men: Evaluation of a 16-City Public Health Program

To examine the impacts of a multi-city HIV prevention public health program (China Global Fund Round 5 Project) on condom use and HIV infection, we analyzed four yearly cross-sectional surveys from 2006 through 2009 among 20,843 men who have sex with men (MSM) in 16 Chinese cities. Self-reported condom use at last sex with a male partner increased from 58% in 2006 to 81% in 2009 (trend test, P<0.001). HIV prevalence increased from 2.3% in 2006 to 5.3% in 2009 (P<0.001). Multivariable logistic regression analysis showed that self-reported receipt of interventions was an independent predictor of increased condom use at last sex with a male partner over time (adjusted odds ratio [aOR], 1.63 in 2006 to 2.33 in 2009; P<0.001), and lower HIV prevalence (aOR, 1.08 in 2006 to 0.45 in 2009; P<0.001). HIV prevalence increased from 2006–2009 for participants with no self-reported receipt of interventions (2.1% in 2006 to 10.3% in 2009) and less so for those with interventions (2.4% to 4.7%). This Chinese public health program had positive impacts on both behaviors and disease rate among MSM population. Escalation of the coverage and intensity of effective interventions is needed for further increasing condom use and for reversing the rising trend of HIV epidemic.     

Prevalence of Consensual Male–Male Sex and Sexual Violence,and Associations with HIV in South Africa: A Population-Based Cross-Sectional Study

Background

In sub-Saharan Africa the population prevalence of men who have sex with men (MSM) is unknown, as is the population prevalence of male-on-male sexual violence, and whether male-on-male sexual violence may relate to HIV risk. This paper describes lifetime prevalence of consensual male–male sexual behavior and male-on-male sexual violence (victimization and perpetration) in two South African provinces, socio-demographic factors associated with these experiences, and associations with HIV serostatus.

Methods and Findings

In a cross-sectional study conducted in 2008, men aged 18–49 y from randomly selected households in the Eastern Cape and KwaZulu-Natal provinces provided anonymous survey data and dried blood spots for HIV serostatus assessment. Interviews were completed in 1,737 of 2,298 (75.6%) of enumerated and eligible households. From these households, 1,705 men (97.1%) provided data on lifetime history of same-sex experiences, and 1,220 (70.2%) also provided dried blood spots for HIV testing. 5.4% (n = 92) of participants reported a lifetime history of any consensual sexual activity with another man; 9.6% (n = 164) reported any sexual victimization by a man, and 3.0% (n = 51) reported perpetrating sexual violence against another man. 85.0% (n = 79) of men with a history of consensual sex with men reported having a current female partner, and 27.7% (n = 26) reported having a current male partner. Of the latter, 80.6% (n = 21/26) also reported having a female partner. Men reporting a history of consensual male–male sexual behavior are more likely to have been a victim of male-on-male sexual violence (adjusted odds ratio [aOR] = 7.24; 95% CI 4.26–12.3), and to have perpetrated sexual violence against another man (aOR = 3.10; 95% CI 1.22–7.90). Men reporting consensual oral/anal sex with a man were more likely to be HIV+ than men with no such history (aOR = 3.11; 95% CI 1.24–7.80). Men who had raped a man were more likely to be HIV+ than non-perpetrators (aOR = 3.58; 95% CI 1.17–10.9).

Conclusions

In this sample, one in 20 men (5.4%) reported lifetime consensual sexual contact with a man, while about one in ten (9.6%) reported experience of male-on-male sexual violence victimization. Men who reported having had sex with men were more likely to be HIV+, as were men who reported perpetrating sexual violence towards other men. Whilst there was no direct measure of male–female concurrency (having overlapping sexual relationships with men and women), the data suggest that this may have been common. These findings suggest that HIV prevention messages regarding male–male sex in South Africa should be mainstreamed with prevention messages for the general population, and sexual health interventions and HIV prevention interventions for South African men should explicitly address male-on-male sexual violence. Please see later in the article for the Editors'' Summary     

The impact of the new WHO antiretroviral treatment guidelines on HIV epidemic dynamics and cost in South Africa

BACKGROUND: Since November 2009, WHO recommends that adults infected with HIV should initiate antiretroviral therapy (ART) at CD4+ cell counts of ≤350 cells/μl rather than ≤200 cells/μl. South Africa decided to adopt this strategy for pregnant and TB co-infected patients only. We estimated the impact of fully adopting the new WHO guidelines on HIV epidemic dynamics and associated costs. METHODS AND FINDING: We used an established model of the transmission and control of HIV in specified sexual networks and healthcare settings. We quantified the model to represent Hlabisa subdistrict, KwaZulu-Natal, South Africa. We predicted the HIV epidemic dynamics, number on ART and program costs under the new guidelines relative to treating patients at ≤200 cells/μl for the next 30 years. During the first five years, the new WHO treatment guidelines require about 7% extra annual investments, whereas 28% more patients receive treatment. Furthermore, there will be a more profound impact on HIV incidence, leading to relatively less annual costs after seven years. The resulting cumulative net costs reach a break-even point after on average 16 years. CONCLUSIONS: Our study strengthens the WHO recommendation of starting ART at ≤350 cells/μl for all HIV-infected patients. Apart from the benefits associated with many life-years saved, a modest frontloading appears to lead to net savings within a limited time-horizon. This finding is robust to alternative assumptions and foreseeable changes in ART prices and effectiveness. Therefore, South Africa should aim at rapidly expanding its healthcare infrastructure to fully embrace the new WHO guidelines.     

A systematic review of African studies on intimate partner violence against pregnant women: prevalence and risk factors

Background

Intimate partner violence (IPV) is very high in Africa. However, information obtained from the increasing number of African studies on IPV among pregnant women has not been scientifically analyzed. This paper presents a systematic review summing up the evidence from African studies on IPV prevalence and risk factors among pregnant women.

Methods

A key-word defined search of various electronic databases, specific journals and reference lists on IPV prevalence and risk factors during pregnancy resulted in 19 peer-reviewed journal articles which matched our inclusion criteria. Quantitative articles about pregnant women from Africa published in English between 2000 and 2010 were reviewed. At least two reviewers assessed each paper for quality and content. We conducted meta-analysis of prevalence data and reported odds ratios of risk factors.

Results

The prevalence of IPV during pregnancy ranges from 2% to 57% (n = 13 studies) with meta-analysis yielding an overall prevalence of 15.23% (95% CI: 14.38 to 16.08%). After adjustment for known confounders, five studies retained significant associations between HIV and IPV during pregnancy (OR1.48–3.10). Five studies demonstrated strong evidence that a history of violence is significantly associated with IPV in pregnancy and alcohol abuse by a partner also increases a woman''s chances of being abused during pregnancy (OR 2.89–11.60). Other risk factors include risky sexual behaviours, low socioeconomic status and young age.

Conclusion

The prevalence of IPV among pregnant women in Africa is one of the highest reported globally. The major risk factors included HIV infection, history of violence and alcohol and drug use. This evidence points to the importance of further research to both better understand IPV during pregnancy and feed into interventions in reproductive health services to prevent and minimize the impact of such violence.     

Addressing the conflict between partner notification and patient confidentiality in serodiscordant relationships: How can Ubuntu help?

This study evaluates the conflict between patient confidentiality and partner notification in sero‐discordant relationships, and argues the thesis that based on a theoretical formulation of Ubuntu, a health provider is obliged to facilitate friendly relationships in which individuals are true subjects and/or objects of communal friendship. In serodiscordant relationships, the health professional can fulfil this obligation by notifying “others” (particularly a partner with whom an HIV positive patient has a “present” and “actual relationship”) of their spouse's HIV seroconversion, since without such relevant information a partner (subject) of an HIV positive patient cannot “appropriately” care for the patient's condition (object). There is a need to move away from the medical traditional emphasis that has for so long put primacy on doctor‐patient confidentiality as is the case with the Health Professions Council of South Africa Guidelines (Booklet 12) which favours patient confidentiality over partner notification. Given empirical evidence to support effectiveness of partner notification amongst sero‐discordant couples, there is thus, a need to focus emphasis on latter. This shift is necessary for achieving the United Nations’ Sustainable Development of Goal of ending HIV/AIDS epidemic by 2030. I proposed in this study that African ethics, specifically Ubuntu, will do a better job than current ethical frameworks at ensuring that partner notification receives more emphasis in the care of serodiscordant couples. If this framework is integrated into ethical guidelines and codes, it would significantly enhance the care of serodiscordant couples, as well as further boost global effort at ending HIV/AIDS epidemic by 2030.     

High Prevalence of Tuberculosis and Insufficient Case Detection in Two Communities in the Western Cape,South Africa

Background

In South Africa the estimated incidence of all forms of tuberculosis (TB) for 2008 was 960/100000. It was reported that all South Africans lived in districts with Directly Observed Therapy, Short-course. However, the 2011 WHO report indicated South Africa as the only country in the world where the TB incidence is still rising.

Aims

To report the results of a TB prevalence survey and to determine the speed of TB case detection in the study communities.

Methods

In 2005 a TB prevalence survey was done to inform the sample size calculation for the ZAMSTAR (Zambia South Africa TB and AIDS Reduction) trial. It was a cluster survey with clustering by enumeration area; all households were visited within enumeration areas and informed consent obtained from eligible adults. A questionnaire was completed and a sputum sample collected from each adult. Samples were inoculated on both liquid mycobacterium growth indicator tube (MGIT) and Löwenstein-Jensen media. A follow-up HIV prevalence survey was done in 2007.

Results

In Community A, the adjusted prevalence of culture positive TB was 32/1000 (95%CI 25–41/1000) and of smear positive TB 8/1000 (95%CI 5–13/1000). In Community B, the adjusted prevalence of culture positive TB was 24/1000 (95%CI 17–32/1000) and of smear positive TB 9/1000 (95%CI 6–15/1000). In Community A the patient diagnostic rate was 0.38/person-year while in community B it was 0.30/person-year. In both communities the adjusted HIV prevalence was 25% (19–30%).

Discussion

In both communities a higher TB prevalence than national estimates and a low patient diagnostic rate was calculated, suggesting that cases are not detected at a sufficient rate to interrupt transmission. These findings may contribute to the rising TB incidence in South Africa. The TB epidemic should therefore be addressed rapidly and effectively, especially in the presence of the concurrently high HIV prevalence.     

A Qualitative Analysis of Factors Influencing HPV Vaccine Uptake in Soweto,South Africa among Adolescents and Their Caregivers

Background

In South Africa, the prevalence of oncogenic Human Papillomavirus (HPV) may be as high as 64%, and cervical cancer is the leading cause of cancer-related death among women. The development of efficacious prophylactic vaccines has provided an opportunity for primary prevention. Given the importance of psycho-social forces in vaccine uptake, we sought to elucidate factors influencing HPV vaccination among a sample of low-income South African adolescents receiving the vaccine for the first time in Soweto.

Methods

The HPV vaccine was introduced to adolescents in low-income townships throughout South Africa as part of a nationwide trial to understand adolescent involvement in future vaccine research targeting human immunodeficiency virus (HIV). We performed in-depth semi-structured interviews with purposively-sampled adolescents and their care providers to understand what forces shaped HPV vaccine uptake. Interviews were recorded, transcribed, translated, and examined using thematic analysis.

Results

Of 224 adolescents recruited, 201 initiated the vaccine; 192 (95.5%) received a second immunization; and 164 (81.6%) completed three doses. In our qualitative study of 39 adolescent-caregiver dyads, we found that factors driving vaccine uptake reflected a socio-cultural backdrop of high HIV endemnicity, sexual violence, poverty, and an abundance of female-headed households. Adolescents exercised a high level of autonomy and often initiated decision-making. Healthcare providers and peers provided support and guidance that was absent at home. The impact of the HIV epidemic on decision-making was substantial, leading participants to mistakenly conflate HPV and HIV.

Conclusions

In a setting of perceived rampant sexual violence and epidemic levels of HIV, adolescents and caregivers sought to decrease harm by seeking a vaccine targeting a sexually transmitted infection (STI). Despite careful consenting, there was confusion regarding the vaccine’s target. Future interventions promoting STI vaccines will need to provide substantial information for participants, particularly adolescents who may exercise a significant level of autonomy in decision-making.     

Understanding the Potential Impact of a Combination HIV Prevention Intervention in a Hyper-Endemic Community

Objectives

Despite demonstrating only partial efficacy in preventing new infections, available HIV prevention interventions could offer a powerful strategy when combined. In anticipation of combination HIV prevention programs and research studies we estimated the population-level impact of combining effective scalable interventions at high population coverage, determined the factors that influence this impact, and estimated the synergy between the components.

Methods

We used a mathematical model to investigate the effect on HIV incidence of a combination HIV prevention intervention comprised of high coverage of HIV testing and counselling, risk reduction following HIV diagnosis, male circumcision for HIV-uninfected men, and antiretroviral therapy (ART) for HIV-infected persons. The model was calibrated to data for KwaZulu-Natal, South Africa, where adult HIV prevalence is approximately 23%.

Results

Compared to current levels of HIV testing, circumcision, and ART, the combined intervention with ART initiation according to current guidelines could reduce HIV incidence by 47%, from 2.3 new infections per 100 person-years (pyar) to 1.2 per 100 pyar within 4 years and by almost 60%, to 1 per 100 pyar, after 25 years. Short-term impact is driven primarily by uptake of testing and reductions in risk behaviour following testing while long-term effects are driven by periodic HIV testing and retention in ART programs. If the combination prevention program incorporated HIV treatment upon diagnosis, incidence could be reduced by 63% after 4 years and by 76% (to about 0.5 per 100 pyar) after 15 years. The full impact of the combination interventions accrues over 10–15 years. Synergy is demonstrated between the intervention components.

Conclusion

High coverage combination of evidence-based strategies could generate substantial reductions in population HIV incidence in an African generalized HIV epidemic setting. The full impact could be underestimated by the short assessment duration of typical evaluations.     

High HIV Prevalence among Asylum Seekers Who Gave Birth in the Netherlands: A Nationwide Study Based on Antenatal HIV Tests

Objectives

Asylum seekers are considered to be a particularly vulnerable group with respect to HIV. Data on the HIV prevalence among asylum seekers, however, are scarce. The aim of this study is to map the HIV prevalence among asylum seekers who gave birth in The Netherlands.

Methods

We used a nationwide electronic medical records database from the community health services for asylum seekers (MOA). The study population consisted of 4,854 women and girls who delivered in asylum reception between 2000 and 2008. A unique electronic health data base was used and case allocation was based on ICPC-codes.

Results

The number of women and girls that was HIV positive during their last pregnancy was 80, of which 79 originated from sub-Saharan Africa. The prevalence for women from this region of origin (3.4%) was high compared to women from all other regions of origin (0.04%; OR = 90.2; 95%CI 12.5–648.8). The highest HIV prevalence rates were found for women from Rwanda (17.0%) and Cameroon (13.2%). HIV prevalence rates were higher among women who arrived in reception without partner (OR = 1.82; 95%CI 0.75–4.44) and unaccompanied minors (OR = 2.59; 95%CI 0.79–8.49), compared to women who arrived in reception with partner.

Conclusions

We conclude that, among asylum-seeking women from sub-Saharan Africa giving birth in The Netherlands, the HIV prevalence is high compared to the host population. For women from other regions of origin, the prevalence is at the same level as in the host population. The high HIV prevalence underlines the importance of preventive interventions and voluntary HIV testing for sub-Saharan African asylum seekers as from shortly after arrival.     

Individual and Population Level Impact of Key HIV Risk Factors on HIV Incidence Rates in Durban,South Africa

We aimed to estimate the individual and joint impact of age, marital status and diagnosis with sexually transmitted infections (STIs) on HIV acquisition among young women at a population level in Durban, KwaZulu-Natal, South Africa. A total of 3,978 HIV seronegative women were recruited for four biomedical intervention trials from 2002–2009. Point and interval estimates of partial population attributable risk (PAR) were used to quantify the proportion of HIV seroconversions which can be prevented if a combination of risk factors is eliminated from a target population. More than 70% of the observed HIV acquisitions were collectively attributed to the three risk factors: younger age (<25 years old), unmarried and not cohabiting with a stable/regular partner and diagnosis with STIs. Addressing these risks requires targeted structural, behavioural, biomedical and cultural interventions in order to impact on unacceptably high HIV incidence rates among young women and the population as a whole.