HIV risk factors in three geographic strata of rural Rakai District, Uganda

The demographic and socioeconomic correlates of behavior and HIV infection status across sub-Saharan Africa

Background

Predisposition to become HIV positive (HIV + ) is influenced by a wide range of correlated economic, environmental, demographic, social, and behavioral factors. While evidence among a candidate handful have strong evidence, there is lack of a consensus among the vast array of variables measured in large surveys.

Methods

We performed a comprehensive data-driven search for correlates of HIV positivity in >600,000 participants of the Demographic and Health Survey across 29 sub-Saharan African countries from 2003 to 2017. We associated a total of 7251 and of 6,288 unique variables with HIV positivity in females and males respectively in each of the 50 surveys. We performed a meta-analysis within countries to attain 29 country-specific associations.

Results

Here we identify 344 (5.4% out possible) and 373 (5.1%) associations with HIV + in males and females, respectively, with robust statistical support. The associations are consistent in directionality across countries and sexes. The association sizes among individual correlates and their predictive capability were low to modest, but comparable to established factors. Among the identified associations, variables identifying being head of household among females was identified in 17 countries with a mean odds ratio (OR) of 2.5 (OR range: 1.1-3.5, R2 = 0.01). Other common associations were identified, including marital status, education, age, and ownership of land or livestock.

Conclusions

Our continent-wide search for variables has identified under-recognized variables associated with being HIV + that are consistent across the continent and sex. Many of the association sizes are as high as established risk factors for HIV positivity, including male circumcision.

Subtype-specific differences in Gag-protease replication capacity of HIV-1 isolates from East and West Africa

BACKGROUND

The HIV-1 epidemic in sub-Saharan Africa is heterogeneous with diverse unevenly distributed subtypes and regional differences in prevalence. Subtype-specific differences in disease progression rate and transmission efficiency have been reported, but the underlying biological mechanisms have not been fully characterized. Here, we tested the hypothesis that the subtypes prevalent in the East Africa, where adult prevalence rate is higher, have lower viral replication capacity (VRC) than their West African counterparts where adult prevalence rates are lower.

RESULTS

Gag-protease sequencing was performed on 213 and 160 antiretroviral-naïve chronically infected participants from West and East Africa respectively and bioinformatic tools were used to infer subtypes and recombination patterns. VRC of patient-derived gag-protease chimeric viruses from West (n = 178) and East (n = 114) Africa were determined using a green fluorescent protein reporter-based cell assay. Subtype and regional differences in VRC and amino acid variants impacting VRC were identified by statistical methods. CRF02_AG (65%, n = 139), other recombinants (14%, n = 30) and pure subtypes (21%, n = 44) were identified in West Africa. Subtypes A1 (64%, n = 103), D (22%, n = 35), or recombinants (14%, n = 22) were identified in East Africa. Viruses from West Africa had significantly higher VRC compared to those from East Africa (p < 0.0001), with subtype-specific differences found among strains within West and East Africa (p < 0.0001). Recombination patterns showed a preference for subtypes D, G or J rather than subtype A in the p6 region of gag, with evidence that subtype-specific differences in this region impact VRC. Furthermore, the Gag A83V polymorphism was associated with reduced VRC in CRF02_AG. HLA-A*23:01 (p = 0.0014) and HLA-C*07:01 (p = 0.002) were associated with lower VRC in subtype A infected individuals from East Africa.

CONCLUSIONS

Although prevalent viruses from West Africa displayed higher VRC than those from East Africa consistent with the hypothesis that lower VRC is associated with higher population prevalence, the predominant CRF02_AG strain in West Africa displayed higher VRC than other prevalent strains suggesting that VRC alone does not explain population prevalence. The study identified viral and host genetic determinants of virus replication capacity for HIV-1 CRF02_AG and subtype A respectively, which may have relevance for vaccine strategies.

Development and Validation of a Sociodemographic and Behavioral Characteristics-Based Risk-Score Algorithm for Targeting HIV Testing Among Adults in Kenya

To inform targeted HIV testing, we developed and externally validated a risk-score algorithm that incorporated behavioral characteristics. Outpatient data from five health facilities in western Kenya, comprising 19,458 adults ≥ 15 years tested for HIV from September 2017 to May 2018, were included in univariable and multivariable analyses used for algorithm development. Data for 11,330 adults attending one high-volume facility were used for validation. Using the final algorithm, patients were grouped into four risk-score categories: ≤ 9, 10-15, 16-29 and ≥ 30, with increasing HIV prevalence of 0.6% [95% confidence interval (CI) 0.46-0.75], 1.35% (95% CI 0.85-1.84), 2.65% (95% CI 1.8-3.51), and 15.15% (95% CI 9.03-21.27), respectively. The algorithm's discrimination performance was modest, with an area under the receiver-operating-curve of 0.69 (95% CI 0.53-0.84). In settings where universal testing is not feasible, a risk-score algorithm can identify sub-populations with higher HIV-risk to be prioritized for HIV testing.

COVID-19 Pandemic as "Curate's Egg" on Human Immunodeficiency Virus Infection: A Commentary

It is a high time not to sideline human immunodeficiency virus (HIV) response during the 2019 coronavirus disease (COVID-19) crisis. COVID-19 will affect the decade’s hard-earned gains from HIV care delivery and response. At the same time, it could be an important time for the COVID-19 containment response to help minimize the occurrence of a new infection. Sexual contact is the main transmission ways in HIV dynamics. However, COVID-19 prevention and control strategies such as movement restrictions, physical and social distancing will reduce exposure to such kinds of risk behaviors. Those containment strategies, including stringent infection prevention and control at health facilities, may minimize transmission of HIV infection and will reduce the incidence of new HIV infection. While recognizing the immense challenges of the COVID-19 pandemic, efforts should be made by governments and international organizations to maintain the response to HIV and to ensure that the progress made against HIV is not lost. In addition, it is very crucial to undertake further researches on the status of new HIV infection during the COVID-19.

Narrating the Transition to Adulthood for Youth in Uganda: Leaving School, Mobility, Risky Occupations, and HIV

School enrollment, mobility, and occupation are each important factors to consider when examining HIV (human immunodeficiency virus) infection risk among youth in sub-Saharan Africa. Through an analysis of narrative life histories from 30 HIV-positive and 30 HIV-negative youth (aged 15-24 years), matched on gender, age, and village and purposively selected and interviewed from the Rakai Community Cohort Study, this article shows the complex connection between leaving school, mobility, and occupation with implications for HIV risk. We identified a pattern of risk factors that was present in many more HIV-positive than HIV-negative youth life stories. These HIV-positive youth shared a similar pathway during their transition to adulthood: After leaving school, they moved in search of occupations; they then engaged in risky occupations before eventually returning to their home village. Linking the lines of inquiry on school enrollment, mobility, and risky occupations, our findings have important implications for adolescent health research, practice, and policy in Uganda and across sub-Saharan Africa and the developing world.

Migration, Sexual Behavior and the Risk of HIV in Kenya

The association of migration with AIDS in sub-Saharan Africa is well documented, yet the social and behavioral mechanisms underlying this relationship remain poorly understood. Using data from the 1993 Kenya Demographic and Health Survey, this article examines whether migrants are more likely than nonmigrants to have multiple recent sexual partners and not use condoms with those partners. Results indicate that migration is a critical factor in high-risk sexual behavior and that its importance varies by gender and by the direction of movement. Independent of marital and cohabitation status, social milieu, awareness of AIDS, and other crucial influences on sexual behavior, male migrants between urban areas and female migrants within rural areas are much more likely than nonmigrant counterparts to engage in sexual practices conducive to HIV infection. In rural areas, migrants from urban places are more likely than nonmigrants to practice high-risk sex. Given the predominance of men in urban migration and the large volume of circulatory movement between urban and rural areas, these results have serious implications for HIV transmission throughout Kenya.

Systematic identification of correlates of HIV infection: an X-wide association study

OBJECTIVE

Better identification of at-risk groups could benefit HIV-1 care programmes. We systematically identified HIV-1 risk factors in two nationally representative cohorts of women in the Demographic and Health Surveys.

METHODS

We identified and replicated the association of 1415 social, economic, environmental, and behavioral factors with HIV-1 status. We used the 2007 and 2013-2014 surveys conducted among 5715 and 15 433 Zambian women, respectively (688 shared factors). We used false discovery rate criteria to identify factors that are strongly associated with HIV-1 in univariate and multivariate models of the entire population, as well as in subgroups stratified by wealth, residence, age, and past HIV-1 testing.

RESULTS

In the univariate analysis, we identified 102 and 182 variables that are associated with HIV-1 in the two surveys, respectively (79 factors were associated in both). Factors that were associated with HIV-1 status in full-sample analyses and in subgroups include being formerly married (adjusted OR 2007, 2.8, P < 10(-16); 2013-2014 2.8, P < 10(-29)), widowhood (aOR 3.7, P < 10(-12); and 4.2, P < 10(-30)), genital ulcers within 12 months (aOR 2.4, P < 10(-5); and 2.2, P < 10(-6)), and having a woman head of the household (aOR 1.7, P < 10(-7); and 2.1, P < 10(-26), while owning a bicycle (aOR 0.6, P < 10(-6); and 0.6, P < 10(-8)) and currently breastfeeding (aOR 0.5, P < 10(-9); and 0.4, P < 10(-26)) were associated with decreased risk. Area under the curve for HIV-1 positivity was 0.76-0.82.

CONCLUSION

Our X-wide association study identifies under-recognized factors related to HIV-1 infection, including widowhood, breastfeeding, and gender of head of the household. These features could be used to improve HIV-1 identification programs.

Cross-sectional comparative study of risky sexual behaviours among HIV-infected persons initiated and waiting to start antiretroviral therapy in rural Rakai, Uganda

OBJECTIVES

To compare risky sexual behaviours between HIV-positive persons initiated on antiretroviral therapy (ART) (ART-experienced) and persons waiting to start on ART (ART-naive) and assess predictors of risky sexual behaviours among HIV-infected patients in rural Rakai district, Uganda.

STUDY DESIGN

This is a cross-sectional study that used data from the Rakai Community Cohort Study (RCCS) database between 2013 and 2014. A structured questionnaire was used for data collection. We used stepwise logistic regression as an index to estimate the adjusted ORs for the association between risky sexual behaviours and ART treatment status.

STUDY SETTING

This study was conducted in Rakai district, located in south-western Uganda. The data for this study were extracted from the RCCS. RCCS is an open prospective cohort of approximately 15 000 consenting participants aged 15-49 years.

PARTICIPANTS

HIV-positive participants aged 18-49 years who had sex at least once a month with any partner prior to the start of the study.

MAIN OUTCOME MEASURES

Inconsistent/no condom use in the last 12 months, alcohol use at last sexual encounter, and two or more sexual partners.

RESULTS

ART-naive participants were more likely to report inconsistent condom use (OR=1.74, 95% CI 1.11 to 2.73) and more likely to drink alcohol at last sexual encounter (OR=1.65, 95% CI 1.11 to 2.46), compared with ART-experienced patients. ART treatment status (p<0.001) was a significant predictor of risky sexual behaviours. Both marital status (p=0.016) and occupation level (p=0.009) were positively associated with inconsistent condom use, while sex (p<0.001) correlated with alcohol use at last sexual encounter.

CONCLUSION

ART-naive participants were more likely to exhibit risky sexual behaviours than the ART-experienced participants. The intensity of risk reduction counselling should be increased for HIV-positive persons waiting to start ART but already in HIV care.

Subtype-Specific Differences in Gag-Protease-Driven Replication Capacity Are Consistent with Intersubtype Differences in HIV-1 Disease Progression

There are marked differences in the spread and prevalence of HIV-1 subtypes worldwide, and differences in clinical progression have been reported. However, the biological reasons underlying these differences are unknown. Gag-protease is essential for HIV-1 replication, and Gag-protease-driven replication capacity has previously been correlated with disease progression. We show that Gag-protease replication capacity correlates significantly with that of whole isolates (r = 0.51; P = 0.04), indicating that Gag-protease is a significant contributor to viral replication capacity. Furthermore, we investigated subtype-specific differences in Gag-protease-driven replication capacity using large well-characterized cohorts in Africa and the Americas. Patient-derived Gag-protease sequences were inserted into an HIV-1 NL4-3 backbone, and the replication capacities of the resulting recombinant viruses were measured in an HIV-1-inducible reporter T cell line by flow cytometry. Recombinant viruses expressing subtype C Gag-proteases exhibited substantially lower replication capacities than those expressing subtype B Gag-proteases (P < 0.0001); this observation remained consistent when representative Gag-protease sequences were engineered into an HIV-1 subtype C backbone. We identified Gag residues 483 and 484, located within the Alix-binding motif involved in virus budding, as major contributors to subtype-specific replicative differences. In East African cohorts, we observed a hierarchy of Gag-protease-driven replication capacities, i.e., subtypes A/C < D < intersubtype recombinants (P < 0.0029), which is consistent with reported intersubtype differences in disease progression. We thus hypothesize that the lower Gag-protease-driven replication capacity of subtypes A and C slows disease progression in individuals infected with these subtypes, which in turn leads to greater opportunity for transmission and thus increased prevalence of these subtypes.IMPORTANCE HIV-1 subtypes are unevenly distributed globally, and there are reported differences in their rates of disease progression and epidemic spread. The biological determinants underlying these differences have not been fully elucidated. Here, we show that HIV-1 Gag-protease-driven replication capacity correlates with the replication capacity of whole virus isolates. We further show that subtype B displays a significantly higher Gag-protease-mediated replication capacity than does subtype C, and we identify a major genetic determinant of these differences. Moreover, in two independent East African cohorts we demonstrate a reproducible hierarchy of Gag-protease-driven replicative capacity, whereby recombinants exhibit the greatest replication, followed by subtype D, followed by subtypes A and C. Our data identify Gag-protease as a major determinant of subtype differences in disease progression among HIV-1 subtypes; furthermore, we propose that the poorer viral replicative capacity of subtypes A and C may paradoxically contribute to their more efficient spread in sub-Saharan Africa.

HIV prevalence and uptake of HIV/AIDS services among youths (15-24 Years) in fishing and neighboring communities of Kasensero, Rakai District, South Western Uganda

BACKGROUND

Although fishing communities have a significantly higher HIV prevalence than the general population, there is paucity of data on the burden of HIV and service utilization, particularly among the youth. We assessed the HIV prevalence and utilization of HIV prevention and treatment services among youth in Kasensero fishing community and the neighboring communities.

METHOD

Data were derived from the Rakai Community Cohort Study (RCCS) surveys conducted between 2013 and 2014. The RCCS is a population-based household survey that collects data annually from individuals aged 15-49 years, resident in 48 communities in Rakai and neighboring districts in Uganda. For this analysis, socio-demographic, behavioral and HIV-related data were obtained for 792 individuals aged 15-24 years. We used logistic regression to conduct bivariate and multivariable analysis to determine the factors that are independently associated with HIV-positive status and their corresponding 95% confidence intervals. Data were analyzed using STATA version 13.

RESULTS

Overall HIV prevalence was 19.7% (n = 155); higher in Kasensero (n = 141; 25.1%) and Gwanda (n = 8; 11%) than in Kyebe (n = 6; 3.9%), p < 0.001 and among females (n = 112; 26.0%) than males (n = 43; 12.0%), p < 0.001. Uptake of HIV testing was high in both HIV-positive (n = 136; 89.5%) and HIV-negative youth (n = 435; 92%). Consistent condom use was virtually non-existent in HIV-positive youth (n = 1; 0.6%) compared to HIV-negative youth (n = 20; 4.2%). Only 22.4% (n = 34) of the HIV-positive youth were receiving antiretroviral therapy (ART) in 2013-2014; higher in the HIV-positive females (n = 31; 28.4%) than HIV-positive males (n = 03; 6.7%). Slightly more than half of males (n = 134; 53.8%) reported that they were circumcised; the proportion of circumcised youth was higher among HIV-negative males (n = 122; 58%) than HIV-positive males (n = 12; 27.9%). Factors significantly associated with HIV-positive status included living in Kasensero landing site (adjusted Odds Ratio [aOR] = 5.0; 95%CI: 2.22-13.01) and reporting one (aOR = 5.0; 95%CI: 1.33-15.80) or 2+ sexual partners in the past 12 months (aOR = 11.0; 95% CI; 3.04-36.72).

CONCLUSION

The prevalence of HIV is high especially among young females and in landing site communities than in the peripheral communities. Uptake of HIV prevention and treatment services is very low. There is an urgent need for youth-friendly services in these communities.

Using nearly full-genome HIV sequence data improves phylogeny reconstruction in a simulated epidemic

HIV molecular epidemiology studies analyse viral pol gene sequences due to their availability, but whole genome sequencing allows to use other genes. We aimed to determine what gene(s) provide(s) the best approximation to the real phylogeny by analysing a simulated epidemic (created as part of the PANGEA_HIV project) with a known transmission tree. We sub-sampled a simulated dataset of 4662 sequences into different combinations of genes (gag-pol-env, gag-pol, gag, pol, env and partial pol) and sampling depths (100%, 60%, 20% and 5%), generating 100 replicates for each case. We built maximum-likelihood trees for each combination using RAxML (GTR + Γ), and compared their topologies to the corresponding true tree’s using CompareTree. The accuracy of the trees was significantly proportional to the length of the sequences used, with the gag-pol-env datasets showing the best performance and gag and partial pol sequences showing the worst. The lowest sampling depths (20% and 5%) greatly reduced the accuracy of tree reconstruction and showed high variability among replicates, especially when using the shortest gene datasets. In conclusion, using longer sequences derived from nearly whole genomes will improve the reliability of phylogenetic reconstruction. With low sample coverage, results can be highly variable, particularly when based on short sequences.

Transactional sex and risk for HIV infection in sub-Saharan Africa: a systematic review and meta-analysis

INTRODUCTION

Young women aged 15 to 24 years in sub-Saharan Africa continue to be disproportionately affected by HIV. A growing number of studies have suggested that the practice of transactional sex may in part explain women's heightened risk, but evidence on the association between transactional sex and HIV has not yet been synthesized. We set out to systematically review studies that assess the relationship between transactional sex and HIV among men and women in sub-Saharan Africa and to summarize the findings through a meta-analysis.

METHODS

The search strategy included 8 databases, hand searches in 10 journals, and searches across 17 websites and portals for organizations as informed by expert colleagues. A systematic review of cross-sectional and longitudinal studies was carried out for studies on women and men who engage in transactional sex published up through 2014. Random effects meta-analysis was used to further examine the relationship between transactional sex and prevalent HIV infection across a subset of studies with the same exposure period. Analyses were conducted separately for men and women.

RESULTS

Nineteen papers from 16 studies met our inclusion criteria. Of these 16 studies, 14 provided data on women and 10 on men. We find a significant, positive, unadjusted or adjusted association between transactional sex and HIV in 10 of 14 studies for women, one of which used a longitudinal design (relative risk (RR)=2.06, 95% confidence interval (CI): 1.22 -3.48). Out of 10 studies involving men, only 2 indicate a positive association between HIV and transactional sex in unadjusted or adjusted models. The meta-analysis confirmed general findings from the systematic review (unadjusted meta-analysis findings are significant for women (n=4; pooled odds ratio (OR)=1.54, 95% CI: 1.04-2.28; I2=42.5%, p=0.156), but not for men (n=4; pooled OR=1.47, 95% CI: 0.85-2.56; I2=50.8%, p=0.107).

CONCLUSIONS

Transactional sex is associated with HIV among women, whereas findings for men were inconclusive. Given that only two studies used a longitudinal approach, there remains a need for better measurement of the practice of transactional sex and additional longitudinal studies to establish the causal pathways between transactional sex and HIV.

Phylogenetic Tools for Generalized HIV-1 Epidemics: Findings from the PANGEA-HIV Methods Comparison

Viral phylogenetic methods contribute to understanding how HIV spreads in populations, and thereby help guide the design of prevention interventions. So far, most analyses have been applied to well-sampled concentrated HIV-1 epidemics in wealthy countries. To direct the use of phylogenetic tools to where the impact of HIV-1 is greatest, the Phylogenetics And Networks for Generalized HIV Epidemics in Africa (PANGEA-HIV) consortium generates full-genome viral sequences from across sub-Saharan Africa. Analyzing these data presents new challenges, since epidemics are principally driven by heterosexual transmission and a smaller fraction of cases is sampled. Here, we show that viral phylogenetic tools can be adapted and used to estimate epidemiological quantities of central importance to HIV-1 prevention in sub-Saharan Africa. We used a community-wide methods comparison exercise on simulated data, where participants were blinded to the true dynamics they were inferring. Two distinct simulations captured generalized HIV-1 epidemics, before and after a large community-level intervention that reduced infection levels. Five research groups participated. Structured coalescent modeling approaches were most successful: phylogenetic estimates of HIV-1 incidence, incidence reductions, and the proportion of transmissions from individuals in their first 3 months of infection correlated with the true values (Pearson correlation > 90%), with small bias. However, on some simulations, true values were markedly outside reported confidence or credibility intervals. The blinded comparison revealed current limits and strengths in using HIV phylogenetics in challenging settings, provided benchmarks for future methods' development, and supports using the latest generation of phylogenetic tools to advance HIV surveillance and prevention.

A Cost-Utility Analysis of Neonatal Circumcision

A cost-utility analysis, based on published data from multiple observational studies, comparing boys circumcised at birth and those not circumcised was undertaken using the Quality of Well-being Scale, a Markov analysis, the standard reference case, and a societal perspective. Neonatal circumcision increased incremental costs by $828.42 per patient and resulted in an incremental 15.30 well-years lost per 1000 males. If neonatal circumcision was cost-free, pain-free, and had no immediate complications, it was still more costly than not circumcising. Using sensitivity analysis, it was impossible to arrange a scenario that made neonatal circumcision cost-effective. Neonatal circumcision is not good health policy, and support for it as a medical procedure cannot be justified financially or medically.

Heterogeneity of the HIV epidemic in agrarian, trading, and fishing communities in Rakai, Uganda: an observational epidemiological study

BACKGROUND

Understanding the extent to which HIV burden differs across communities and the drivers of local disparities is crucial for an effective and targeted HIV response. We assessed community-level variations in HIV prevalence, risk factors, and treatment and prevention service uptake in Rakai, Uganda.

METHODS

The Rakai Community Cohort Study (RCCS) is an open, population-based cohort of people aged 15-49 years in 40 communities. Participants are HIV tested and interviewed to obtain sociodemographic, behavioural, and health information. RCCS data from Aug 10, 2011, to May 30, 2013, were used to classify communities as agrarian (n=27), trading (n=9), or lakeside fishing sites (n=4). We mapped HIV prevalence with Bayesian methods, and characterised variability across and within community classifications. We also assessed differences in HIV risk factors and uptake of antiretroviral therapy and male circumcision between community types.

FINDINGS

17 119 individuals were included, 9215 (54%) of whom were female. 9931 participants resided in agrarian, 3318 in trading, and 3870 in fishing communities. Median HIV prevalence was higher in fishing communities (42%, range 38-43) than in trading (17%, 11-21) and agrarian communities (14%, 9-26). Antiretroviral therapy use was significantly lower in both men and women in fishing communities than in trading (age-adjusted prevalence risk ratio in men 0·64, 95% CI 0·44-0·97; women 0·53, 0·42-0·66) and agrarian communities (men 0·55, 0·42-0·72; women 0·65, 0·54-0·79), as was circumcision coverage among men (vs trading 0·48, 0·42-0·55; vs agrarian 0·64, 0·56-0·72). Self-reported risk behaviours were significantly higher in men than in women and in fishing communities than in other community types.

INTERPRETATION

Substantial heterogeneity in HIV prevalence, risk factors, and service uptake in Rakai, Uganda, emphasises the need for local surveillance and the design of targeted HIV responses. High HIV burden, risk behaviours, and low use of combination HIV prevention in fishing communities make these populations a priority for intervention.

FUNDING

National Institute of Mental Health, the National Institute of Allergy and Infectious Diseases, the National Institute of Child Health and Development, and the National Institute for Allergy and Infectious Diseases Division of Intramural Research, National Institutes of Health; the Bill & Melinda Gates Foundation; and the Johns Hopkins University Center for AIDS Research.

Mobility among youth in Rakai, Uganda: Trends, characteristics, and associations with behavioural risk factors for HIV

Mobility, including migration and travel, influences risk of HIV. This study examined time trends and characteristics among mobile youth (15-24 years) in rural Uganda, and the relationship between mobility and risk factors for HIV. We used data from an annual household census and population-based cohort study in the Rakai district, Uganda. Data on in-migration and out-migration were collected among youth (15-24 years) from 43 communities from 1999 to 2011 (N = 112,117 observations) and travel among youth residents from 2003 to 2008 (N = 18,318 observations). Migration and travel were more common among young women than young men. One in five youth reported out-migration. Over time, out-migration increased among youth and in-migration remained largely stable. Primary reasons for migration included work, living with friends or family, and marriage. Recent travel within Uganda was common and increased slightly over time in teen women (15-19 years old), and young adult men and women (20-24 years old). Mobile youth were more likely to report HIV-risk behaviours including: alcohol use, sexual experience, multiple partners, and inconsistent condom use. Our findings suggest that among rural Ugandan youth, mobility is increasingly common and associated with HIV-risk factors. Knowledge of patterns and characteristics of a young, high-risk mobile population has important implications for HIV interventions.

Combined Intimate Partner Violence and HIV/AIDS Prevention in Rural Uganda: Design of the SHARE Intervention Strategy

Intimate partner violence (IPV) has a bidirectional relationship with HIV infection. Researchers from the Rakai Health Sciences Program (RHSP), an HIV research and services organization in rural Uganda, conducted a combination IPV and HIV prevention intervention called the Safe Homes and Respect for Everyone (SHARE) Project between 2005 and 2009. SHARE was associated with significant declines in physical and sexual IPV and overall HIV incidence, and its model could be adopted as a promising practice in other settings. In this article we describe how SHARE's IPV-prevention strategies were integrated into RHSP's existing HIV programming and provide recommendations for replication of the approach.

Genital schistosomiasis and its unacknowledged role on HIV transmission in the STD intervention studies

Treatment of sexually transmitted infections (STIs) has been hypothesised to decrease HIV transmission. Although observational studies show an association between STIs and HIV, only one prospective randomised controlled trial (RCT) has confirmed this. Female genital schistosomiasis can cause genital lesions, accompanied by bloody discharge, ulcers or malodorous discharge. Genital schistosomiasis is common, starts before puberty and symptoms can be mistaken for STIs. Three observational studies have found an association between schistosomiasis and HIV. Genital lesions that develop in childhood are chronic. This paper sought to explore the possible effects of schistosomiasis on the RCTs of STI treatment for HIV prevention.

In the study sites, schistosomiasis was a likely cause of genital lesions. The studies recruited women that may have had genital schistosomal lesions established in childhood. Schistosomiasis endemic areas with different prevalence levels may have influenced HIV incidence in intervention and control sites differently, and some control group interventions may have influenced the impact of schistosomiasis on the study results. Schistosomiasis is a neglected cause of genital tract disease. It may have been an independent cause of HIV incidence in the RCTs of STI treatment for HIV prevention and may have obscured the findings of these trials.

Effects of hormonal contraceptive use on HIV acquisition and transmission among HIV-discordant couples

BACKGROUND

The risk of HIV associated with hormonal contraceptives is controversial. We assessed hormonal contraceptive use and HIV incidence in HIV-discordant couples in Rakai, Uganda.

METHODS

HIV-discordant couples were retrospectively identified from a cohort between 1999 and 2009. Hormonal contraception included oral contraception, depomedroxyprogesterone acetate (DMPA), and implants (Norplant). Poisson regression estimated adjusted incidence rate ratios (adjIRRs) associated with hormonal contraceptive methods. A case-control subanalysis estimated odds ratios (ORs) of HIV associated with hormonal contraceptive, adjusted for viral load and age.

RESULTS

We identified 190 male HIV-positive/female HIV-negative (M+F-) and 159 male HIV- negative/female HIV-positive (M-F+) couples not using antiretroviral therapy or condoms. Female HIV incidence was 5.8/100 person-years (py) among nonhormonal contraceptive users, 12.0/100 py among oral contraceptive users [adjIRR 2.65, 95% confidence interval (CI) 0.82-8.60], 4.5 among Norplant users (adjIRR: 0.89, 95% CI 0.11-7.10), and 7.5/100 py among DMPA users (adjIRR 1.42, 95% CI 0.60-3.36). Male HIV incidence was 7.4/100 py during nonhormonal contraceptive use, 16.5/100 py during female oral contraceptive use (adjIRR 2.52, 95% CI 0.49-12.95), and 4.9/100 py with DMPA use (adjIRR 0.57, 95% CI 0.19-1.70). The number of female seroconverters was three among oral contraceptive users, one among Norplant users, and seven among DMPA users. Male seroconverters were two during female oral contraceptive use, none with Norplant use, and three with DMPA use. In a nested case-control analysis after adjustment for HIV viral load, the adjOR associated with oral contraceptive use was 1.59 (95% CI 0.32-97.85) for M+F- and 2.11 (95% CI 0.18-25.26) for M-F+ couples. For DMPA use, the adjOR was 1.44 (95% CI 0.46-4.51) for M+F- and 1.40 (95% CI 0.30-6.49) for M-F+ couples.

CONCLUSION

We did not observe significant risk of HIV acquisition or transmission with oral contraceptives or DMPA use in HIV discordant couples, but several point estimates were above 1.0 and statistical power was limited.

Behavioral, biological, and demographic risk and protective factors for new HIV infections among youth in Rakai, Uganda

BACKGROUND

Prevalence of HIV infection is considerable among youth, although data on risk factors for new (incident) infections are limited. We examined incidence of HIV infection and risk and protective factors among youth in rural Uganda, including the role of gender and social transitions.

METHODS

Participants were sexually experienced youth (15-24 years old) enrolled in the Rakai Community Cohort Study, 1999-2008 (n = 6741). Poisson regression with robust standard errors was used to estimate incident rate ratios (IRR) and 95% confidence intervals (CI) of incident HIV infection.

RESULTS

HIV incidence was greater among young women than young men (14.1 vs. 8.3 per 1000 person-years, respectively); this gender disparity was greater among teenagers (14.9 vs. 3.6). Beyond behavioral (multiple partners and concurrency) and biological factors (sexually transmitted infection symptoms), social transitions such as marriage and staying in school influenced HIV risk. In multivariate analyses among women, HIV incidence was associated with living in a trading village (adjusted IRR (aIRR) = 1.48; 95% CI: 1.04 to 2.11), being a student (aIRR = 0.22; 95% CI: 0.07 to 0.72), current marriage (aIRR = 0.55; 95% CI: 0.37 to 0.81), former marriage (aIRR = 1.73; 95% CI: 1.01 to 2.96), having multiple partners, and sexually transmitted infection symptoms. Among men, new infections were associated with former marriage (aIRR = 5.57; 95% CI: 2.51 to 12.36), genital ulceration (aIRR = 3.56; 95% CI: 1.97 to 6.41), and alcohol use (aIRR = 2.08; 95% CI: 1.15 to 3.77).

CONCLUSIONS

During the third decade of the HIV epidemic in Uganda, HIV incidence remains considerable among youth, with young women particularly at risk. The risk for new infections was strongly shaped by social transitions such as leaving school, entrance into marriage, and marital dissolution; the impact of marriage was different for young men than women.

HIV and Schistosoma haematobium prevalences correlate in sub-Saharan Africa

OBJECTIVE

Epidemiological studies have observed that genital schistosomiasis increases the risk of HIV infection in Africa. We analysed the correlation between Schistosoma haematobium prevalence and HIV prevalence across sub-Saharan African countries.

DESIGN

Regression analysis of prevalence of HIV and S. haematobium across sub-Saharan African countries.

METHODS

Using compiled country-level S. haematobium prevalence, HIV prevalence and other demographic and economic data from published sources, we applied univariate and multivariate regression models to assess the correlations between S. haematobium prevalence and HIV prevalence while controlling for risk factors associated with each infection.

RESULTS

In 43 sub-Saharan African countries, the mean prevalence of S. haematobium was 22.4% [standard deviation (SD): 9.8%] and for HIV was 6.21% (SD: 5.71%). In multivariate analysis, adjusted for prevalence of male circumcision, years since a country's first HIV/AIDS diagnosis, geographical region and immunization coverage, each S. haematobium infection per 100 individuals was associated with a 2.9% (95% CI: 0.2-5.8%) relative increase in HIV prevalence. S. haematobium was not associated with Schistosoma mansoni, HSV-2, hepatitis C, malaria or syphilis.

CONCLUSIONS

Schistosoma haematobium prevalence was associated with HIV prevalence in sub-Saharan Africa. Controlling S. haematobium may be an effective means of reducing HIV transmission in sub-Saharan Africa.

The spatial and temporal association of neighborhood drug markets and rates of sexually transmitted infections in an urban setting

This study examined temporal and spatial relationships between neighborhood drug markets and gonorrhea among census block groups from 2002 to 2005. This was a spatial, longitudinal ecologic study. Poisson regression was used with adjustment in final models for socioeconomic status, residential stability and vacant housing. Increased drug market arrests were significantly associated with a 11% increase gonorrhea (adjusted relative risk (ARR) 1.11; 95% CI 1.05, 1.16). Increased drug market arrests in adjacent neighborhoods were significantly associated with a 27% increase in gonorrhea (ARR 1.27; 95% CI 1.16, 1.36), independent of focal neighborhood drug markets. Increased drug market arrests in the previous year in focal neighborhoods were not associated with gonorrhea (ARR 1.04; 95% CI 0.98, 1.10), adjusting for focal and adjacent drug markets. While the temporal was not supported, our findings support an associative link between drug markets and gonorrhea. The findings suggest that drug markets and their associated sexual networks may extend beyond local neighborhood boundaries indicating the importance of including spatial lags in regression models investigating these associations.

Assessment of changes in risk behaviors during 3 years of posttrial follow-up of male circumcision trial participants uncircumcised at trial closure in Rakai, Uganda

Risk compensation associated with male circumcision has been a concern for male circumcision scale-up programs. Using posttrial data collected during 2007-2011 on 2,137 male circumcision trial participants who were uncircumcised at trial closure in Rakai, Uganda, the authors evaluated their sexual behavioral changes during approximately 3 years' follow-up after trial closure. Eighty-one percent of the men self-selected for male circumcision during the period, and their sociodemographic and risk profiles were comparable to those of men remaining uncircumcised. Linear models for marginal probabilities of repeated outcomes estimate that 3.3% (P < 0.0001) of the male circumcision acceptors reduced their engagement in nonmarital relations, whereas there was no significant change among men remaining uncircumcised. Significant decreases in condom use occurred in both male circumcision acceptors (-9.2% with all partners and -7.0% with nonmarital partners) and nonacceptors (-12.4% and -13.5%, respectively), and these were predominantly among younger men. However, the magnitudes of decrease in condom use were not significantly different between the 2 groups. Additionally, significant decreases in sex-related alcohol consumption were observed in both groups (-7.8% in male circumcision acceptors and -6.1% in nonacceptors), mainly among older men. In summary, there was no evidence of risk compensation associated with male circumcision among this cohort of men during 3 years of posttrial follow-up.

Demographic predictors of HIV serostatus among HIV counseling and testing clients in rural Nigeria

Nnewi is a rural Nigerian town with a human immunodeficiency virus (HIV) counseling and testing center which tests about 120 clients/d. The objective of this study is to determine the factors predicting positive HIV status at Nnewi. Review of records was done with age, gender, marital status, and occupation as variables. Logistic regression analysis was used to identify factors linked to a positive HIV test. Overall HIV prevalence was 31.14%. Drivers and married clients had a high risk of being HIV+ (odds ratio [OR], 3.59; 95% confidence interval [CI], 2.17-5.96 and OR, 2.78; 95% CI, 2.42-3.19). Housewives were 2 times more likely to be positive (OR, 2.11; 95% CI, 1.35-3.29). After adjustment, females had 22% higher risk (OR, 1.22; 95% CI, 1.03-1.45) with the highest chance found in married females (OR, 6.70; 95% CI, 4.45-10.09). The study succeeded in panning out an unexpected risk group: married women. Drivers have been known to be a risk group. Preventive methods must be tailored to and acceptable by each risk group.

Proportion of Urinary Schistosomiasis among HIV-Infected Subjects in Benin City, Nigeria

OBJECTIVES

This study aimed to determine the prevalence of urinary schistosomiasis, and the effect of CD4(+) T cell counts and demographics on its prevalence among HIV-positive patients in Benin City, Nigeria.

METHODS

Urine and blood samples were collected from 2000 HIV-positive subjects. A wet preparation of the urine deposit was examined microscopically to identify ova of Schistosoma haematobium. The blood specimens were analyzed using the flow cytometry for CD4 (+) T-lymphocyte count.

RESULTS

An overall prevalence rate of 0.3% was reported. Gender and CD4 count <200 cells/µL did not affect the prevalence of urinary schistosomiasis, while HIV patients that were single had significantly higher prevalence of urinary schistosomiasis (p=0.002).

CONCLUSION

The prevalence of urinary schistosomiasis among HIV patients in Benin City is low. CD4(+) count did not affect the prevalence of urinary schistosomiasis.

More on the cohort-component model of population projection in the context of HIV/AIDS: A Leslie matrix representation and new estimates

This article presents an extension of the cohort-component model of population projection (CCMPP) first formulated by Heuveline (2003) that is capable of modeling a population affected by HIV. Heuveline proposes a maximum likelihood approach to estimate the age profile of HIV incidence that produced the HIV epidemics in East Africa during the 1990s. We extend this work by developing the Leslie matrix representation of the CCMPP, which greatly facilitates the implementation of the model for parameter estimation and projection. The Leslie matrix also contains information about the stable tendencies of the corresponding population, such as the stable age distribution and time to stability. Another contribution of this work is that we update the sources of data used to estimate the parameters, and use these data to estimate a modified version of the CCMPP that includes (estimated) parameters governing the survival experience of the infected population. A further application of the model to a small population with high HIV prevalence in rural South Africa is presented as an additional demonstration. This work lays the foundation for development of more robust and flexible Bayesian estimation methods that will greatly enhance the utility of this and similar models.

Spatial and socio-behavioral patterns of HIV prevalence in the Democratic Republic of Congo

This study uses a 2007 population-based household survey to examine the individual and community-level factors that increase an individual's risk for HIV infection in the Democratic Republic of Congo (DRC). Using the 2007 DRC Demographic Health Surveillance (DHS) Survey, we use spatial analytical methods to explore sub-regional patterns of HIV infection in the DRC. Geographic coordinates of survey communities are used to map prevalence of HIV infection and explore geographic variables related to HIV risk. Spatial cluster techniques are used to identify hotspots of infection. HIV prevalence is related to individual demographic characteristics and sexual behaviors and community-level factors. We found that the prevalence of HIV within 25 km of an individual's community is an important positive indicator of HIV infection. Distance from a city is negatively associated with HIV infection overall and for women in particular. This study highlights the importance of improved surveillance systems in the DRC and other African countries along with the use of spatial analytical methods to enhance understanding of the determinants of HIV infection and geographic patterns of prevalence, thereby contributing to improved allocation of public health resources in the future.

High HIV prevalence and associated factors in a remote community in the Rwenzori region of Western Uganda

In Uganda, previous studies have shown a tremendous decline in HIV prevalence over the past two decades due to changes in sexual behavior with a greater awareness of the risks involved. However, studies in Fort-Portal municipality, a rural town in Western Uganda, continued to show a persistent high HIV prevalence despite the various interventions in place. We conducted a study to establish the current magnitude of HIV prevalence and the factors associated with HIV prevalence in this community. This cross-sectional study was conducted between July and November 2008. Participants were residents of Fort-Portal municipality aged 15-49 years. A populationbased HIV sero-survey and a clinical review of prevention of mother to child HIV transmission (PMTCT) and voluntary counseling and HIV Testing (VCT) records were used to collect quantitative data. An inteviewer administered structured questionnaire was used to collect qualitative data on social deographics, risk behaviour and community perceptions. Focus group discussions (FGDs) and in-depth interviews provided supplementary data on community perceptions. Logistic regression was used in the analysis. The overall HIV prevalence in the general population was 16.1% [95% CI; 12.5-20.6]. Prevalence was lower among women (14.5%; 95% CI; 10.0-19.7) but not significantly different from that among men (18.7%; 95% CI; 12.5-26.3) (χ(2) =0.76, P=0.38). Having more than 2 sexual partners increased the odds of HIV by almost 2.5 times. None or low education and age over 35 years were independently associated with HIV prevalence (P<0.05). Most participants attributed the high HIV prevalence to promiscuity/multiple sexual partners (32.5%), followed by prostitution (13.6%), alcoholism (10.1%), carelessness (10.1%), poverty (9.7%), ignorance (9.5%)), rape (4.7%), drug abuse (3.6%) and others (malice/malevolence, laziness, etc.) (6.2%). Although there was a slight decline compared to previous reports, the results from this study confirm that HIV prevalence is still high in this community. In order to prevent new infections, the factors mentioned above need to be addressed, and we recommend that education aimed at changing individual behavior should be intensified in this community.

Spatial mobility, alcohol use, sexual behavior and sexual health among males in India

This paper examines the linkages of permanent migration, temporary mobility and alcohol consumption with risky sexual behavior and sexually transmitted infections (STIs) including HIV infection among males in India using a nationally representative dataset. The study shows that non-migrant men and migrant men do not differ significantly in any indicator of risky sexual behavior and STIs. Temporary long duration mobile men reported significantly more often than the non-mobile men or short duration mobile men that they had sex with multiple sex partners during their lifetime as well as sex with a high risk partner and had paid sex in the 12 months preceding the survey. Males who drank alcohol almost every day notwithstanding with their migration or mobility status were most prone to lifelong as well as more recent sexual risk behavior. Controlling for sociodemographic characteristics long duration mobile men and men who used alcohol almost daily had higher sexual risk behaviors and STI infections. Further migration and mobility did not show any significant relationship with tested HIV prevalence among males in India, controlling for sociodemographic characteristics. Males who had lifetime multiple sex partners were at the highest risk of tested HIV infection controlling for sociodemographic characteristics, migration, mobility, alcohol use and STI infection. Interventions focusing on HIV prevention in India need to target both non-migrant and migrant men, particularly those who drink alcohol more frequently or daily. Targeted interventions are required for temporary mobile men, particularly for those mobile men who have to stay away from their homes continuously for a longer duration. Long duration mobile men are most prone to regular alcohol use and risky sexual behavior.

Spatial distribution and cluster analysis of sexual risk behaviors reported by young men in Kisumu, Kenya

BACKGROUND

The well-established connection between HIV risk behavior and place of residence points to the importance of geographic clustering in the potential transmission of HIV and other sexually transmitted infections (STI).

METHODS

To investigate the geospatial distribution of prevalent sexually transmitted infections and sexual behaviors in a sample of 18-24 year-old sexually active men in urban and rural areas of Kisumu, Kenya, we mapped the residences of 649 men and conducted spatial cluster analysis. Spatial distribution of the study participants was assessed in terms of the demographic, behavioral, and sexual dysfunction variables, as well as laboratory diagnosed STIs. To test for the presence and location of clusters we used Kulldorff's spatial scan statistic as implemented in the Satscan program.

RESULTS

The results of this study suggest that sexual risk behaviors and STIs are evenly distributed in our sample throughout the Kisumu district. No behavioral or STI clusters were detected, except for condom use. Neither urban nor rural residence significantly impacted risk behavior or STI prevalence.

CONCLUSION

We found no association between place of residence and sexual risk behaviors in our sample. While our results can not be generalized to other populations, the study shows that geospatial analysis can be an important tool for investigating study sample characteristics; for evaluating HIV/STI risk factors; and for development and implementation of targeted HIV and STI control programs in specifically defined populations and in areas where the underlying population dynamic is poorly understood.

Rectal gonorrhea and chlamydia reinfection is associated with increased risk of HIV seroconversion

INTRODUCTION

HIV infection continues to disproportionately affect men who have sex with men (MSM). Identification of modifiable risk factors for HIV infection among MSM is critical for effective prevention.

METHODS

We examined the relationship between number of prior rectal Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT) infections and HIV seroconversion in a retrospective cohort of HIV-uninfected MSM diagnosed with a rectal infection. Number of rectal CT or GC infections in the prior 2 years was the primary exposure. Univariate and multivariate Cox proportional hazards models were used to estimate the association between prior rectal infections and HIV seroconversion.

RESULTS

A total of 541 MSM were observed for a total of 1197.96 person-years. Overall, 27 (4.99%) of the MSM became infected with HIV, for an estimated annual incidence of 2.25% [95% confidence interval (CI): 1.49 to 3.26]. In multivariate analysis, an early syphilis diagnosis in the past 2 years (hazard ratio = 4.04, 95% CI: 1.19 to 13.79) and 2 prior CT or GC rectal infections in the past 2 years (hazard ratio = 8.85, 95% CI: 2.57 to 30.40) were associated with incident HIV.

CONCLUSIONS

Among MSM infected with rectal GC or CT, a history of 2 additional prior rectal infections was associated with an 8-fold increased risk of HIV infection. HIV-uninfected MSM with multiple rectal infections represent a population in need of innovative HIV-prevention interventions.

Sexualised space, sexual networking & the emergence of AIDS in Rakai, Uganda

This paper argues that the outbreak of the epidemic of AIDS in Rakai, Uganda, in the early 1980s was a consequence of economic change, leading to the erosion of conventional cultural checks on juvenile, female and male sexuality and the emergence and growth of sexualised spaces and sexual networking in a few remote rural hubs of economic activity which exhibited a different sexual culture from the surrounding countryside. The trading hubs developed dense local and regional sexual networks which enabled HIV to spread quickly among the "risk groups" and local people of the busiest trading towns and villages. The high degree of sexual mixing in these hubs opened up new routes for HIV to infect the general population. This paper, which shows the importance of understanding the role of the aggravated economic disparities and changing sexual culture in the onset and spread of the HIV and AIDS epidemic in Rakai, Uganda, is primarily based on in-depth interviews and focus group discussions and on the analysis of newspapers, unofficial and official documents and academic studies.

Rethinking the role of the local community in HIV epidemic spread in sub-Saharan Africa: a proximate-determinants approach

The spread of HIV in sub-Saharan Africa continues largely unabated. To improve prevention interventions, a better understanding of the determinants of HIV infection is required. Conceptual frameworks can guide epidemiological investigation and prevent a misguided focus on single risk factors in isolation. Existing frameworks of HIV infection focus on transmission. However, the transmitting individual is rarely known. By contrast, data on individual HIV acquisition are available from longitudinal studies and tests for recent HIV infection. From the perspective of individuals susceptible to HIV, it is important to distinguish between factors determining the individual's biological disposition and sexual behavior and community-level factors, which can affect both HIV acquisition and the likelihood that a sex partner chosen from a community will be infected with HIV and transmit the infection. We propose a framework that takes the susceptible individual as a starting point and links distal, proximate and biological determinants of HIV infection at both the individual and the community level. We describe three necessary ingredients for the use of the framework (identification of the relevant community, multilevel analysis and methods for causal inference).

Education and vulnerability: the role of schools in protecting young women and girls from HIV in southern Africa

Education has a potentially important role to play in tackling the spread of HIV, but is there evidence that this potential is realized? This analysis combines the results of previous literature reviews and updates them with the findings of recent randomized controlled trials and a discussion of possible mechanisms for the effect of schooling on vulnerability to HIV infection. There is a growing body of evidence that keeping girls in school reduces their risk of contracting HIV. The relationship between educational attainment and HIV has changed over time, with educational attainment now more likely to be associated with a lower risk of HIV infection than earlier in the epidemic. Educational attainment cannot, however, be isolated from other socioeconomic factors as the cause of HIV risk reduction. The findings of this analysis suggest that the equitable expansion of primary and secondary schooling for girls in southern Africa will help reduce their vulnerability to HIV. Evidence of ineffective HIV prevention education in schools underlines the need for careful evidence-based programme design. Despite the challenges, recent provisional evidence suggests that highly targeted programmes promoting realistic options for young adults may lead to safer sexual behaviour. Targeted education programmes have also been successful in changing students' attitudes to people living with HIV and AIDS, which is associated with testing and treatment decisions. This reduction in stigma may be crucial in encouraging the uptake of voluntary counselling and testing, a central strategy in the control of the epidemic. Expansions of carefully designed and evaluated school-based HIV prevention programmes can help to reduce stigma and have the potential to promote safe sexual behaviour.

Structural approaches to HIV prevention

Recognition that social, economic, political, and environmental factors directly affect HIV risk and vulnerability has stimulated interest in structural approaches to HIV prevention. Progress in the use of structural approaches has been limited for several reasons: absence of a clear definition; lack of operational guidance; and limited data on the effectiveness of structural approaches to the reduction of HIV incidence. In this paper we build on evidence and experience to address these gaps. We begin by defining structural factors and approaches. We describe the available evidence on their effectiveness and discuss methodological challenges to the assessment of these often complex efforts to reduce HIV risk and vulnerability. We identify core principles for implementing this kind of work. We also provide recommendations for ensuring the integration of structural approaches as part of combined prevention strategies.

HIV prevalence and incidence are no longer falling in southwest Uganda: evidence from a rural population cohort 1989-2005

BACKGROUND

Throughout the 1990s, HIV-1 prevalence and incidence were falling in Uganda. Recently, some researchers have noticed that HIV-1 prevalence is levelling off. We examine prevalence, incidence, and sexual behaviour trends in a rural population cohort in Uganda over 16 years.

METHODS

We report prevalence by survey round and incidence by calendar year from a prospective general population cohort study. Using logistic regression Wald tests, we examined casual partners, condom use, and pregnancies. We examined age at sexual debut by means of life tables.

RESULTS

HIV-1 prevalence declined from 8.5% in 1990/1991 to 6.2% in 1999/2000, and thereafter rose to 7.7% in 2004/2005. Incidence (per 1000 person-years at risk) fell from 7.5 in 1990 to 4.1 in 1998, and thereafter increased to 5.0 by 2004. The 2005 incidence estimate reached an all-time low of 2.5, but the preliminary 2006 estimate shows a rise again. Incidence trends varied by age and sex. Some sexual behaviour indicators showed more risky behaviour in recent years compared with the 1990s, whereas others indicated that the reduction in risky behaviour that began in the 1990s continues.

CONCLUSION

HIV-1 prevalence is rising in this cohort. Incidence is stabilizing, and shows signs of increasing among some subgroups. The extent to which changing sexual behaviour has played a role in these epidemiological trends is unclear, but it is likely to have contributed. To solidify the success that Uganda had throughout the 1990s in controlling the HIV epidemic, the efforts in HIV prevention need to be re-strengthened, using all strategies known.

Systematic review exploring time trends in the association between educational attainment and risk of HIV infection in sub-Saharan Africa

OBJECTIVE

To assess the evidence that the association between educational attainment and risk of HIV infection is changing over time in sub-Saharan Africa.

DESIGN AND METHODS

Systematic review of published peer-reviewed articles. Articles were identified that reported original data comparing individually measured educational attainment and HIV status among at least 300 individuals representative of the general population of countries or regions of sub-Saharan Africa. Statistical analyses were required to adjust for potential confounders but not over-adjust for variables on the causal pathway.

RESULTS

Approximately 4000 abstracts and 1200 full papers were reviewed. Thirty-six articles were included in the study, containing data on 72 discrete populations from 11 countries between 1987 and 2003, representing over 200,000 individuals. Studies on data collected prior to 1996 generally found either no association or the highest risk of HIV infection among the most educated. Studies conducted from 1996 onwards were more likely to find a lower risk of HIV infection among the most educated. Where data over time were available, HIV prevalence fell more consistently among highly educated groups than among less educated groups, in whom HIV prevalence sometimes rose while overall population prevalence was falling. In several populations, associations suggesting greater HIV risk in the more educated at earlier time points were replaced by weaker associations later.

DISCUSSION

HIV infections appear to be shifting towards higher prevalence among the least educated in sub-Saharan Africa, reversing previous patterns. Policy responses that ensure HIV-prevention measures reach all strata of society and increase education levels are urgently needed.

Relating diarrheal disease to social networks and the geographic configuration of communities in rural Ecuador

Social networks and geographic structures of communities are important predictors of infectious disease transmission. To examine their joint effects on diarrheal disease and how these effects might develop, the authors analyzed social network and geographic data from northern coastal Ecuador and examined associations with diarrhea prevalence. Between July 2003 and May 2005, 113 cases of diarrhea were identified in nine communities. Concurrently, sociometric surveys were conducted, and households were mapped with geographic information systems. Spatial distribution metrics of households within communities and of communities with respect to roads were developed that predict social network degree in casual contact ("contact") and food-sharing ("food") networks. The mean degree is 25-40% lower in communities with versus without road access and 66-94% lower in communities with lowest versus highest housing density. Associations with diarrheal disease were found for housing density (comparing dense with dispersed communities: risk ratio = 3.3, 95% confidence interval (CI): 1.1, 10.0) and social connectedness (comparing lowest with highest degree communities: risk ratio = 3.4, 95% CI: 1.1, 10.1 in the contact network and risk ratio = 4.9, 95% CI: 1.1, 21.9 in the food network). Some of these differences may be related to more new residents, lower housing density, and less social connectedness in road communities.

Sexual risk factors for HIV infection in early and advanced HIV epidemics in sub-Saharan Africa: systematic overview of 68 epidemiological studies

Background

It is commonly assumed that sexual risk factors for heterosexual HIV transmission in sub-Saharan Africa, such as multi-partner sex, paid sex and co-infections, become less important as HIV epidemics mature and prevalence increases.

Methods and Findings

We conducted a systematic review of 68 African epidemiological studies from 1986 to 2006 involving 17,000 HIV positive adults and 73,000 controls. We used random-effects methods and stratified results by gender, time, background HIV prevalence rates and other variables. The number of sex partners, history of paid sex, and infection with herpes simplex virus (HSV-2) or other sexually-transmitted infections (STIs) each showed significant associations with HIV infection. Among the general population, the odds ratio (OR) of HIV infection for women reporting 3+ sex partners versus 0–2 was 3.64 (95%CI [2.87–4.62]), with similar risks for men. About 9% of infected women reported ever having been paid for sex, versus 4% of control women (OR = 2.29, [1.45–3.62]). About 31% of infected men reported ever paying for sex versus 18% of uninfected men (OR = 1.75, [1.30–2.36]). HSV-2 infection carried the largest risk of HIV infection: OR = 4.62, [2.85–7.47] in women, and OR = 6.97, [4.68–10.38] in men. These risks changed little over time and stratification by lower and higher HIV background prevalence showed that risk ratios for most variables were larger in high prevalence settings. Among uninfected controls, the male-female differences in the number of sex partners and in paid sex were more extreme in the higher HIV prevalence settings than in the lower prevalence settings.

Significance

Multi-partner sex, paid sex, STIs and HSV-2 infection are as important to HIV transmission in advanced as in early HIV epidemics. Even in high prevalence settings, prevention among people with high rates of partner change, such as female sex workers and their male clients, is likely to reduce transmission overall.

Continued very high prevalence of HIV infection in rural KwaZulu-Natal, South Africa: a population-based longitudinal study

OBJECTIVE

To estimate the prevalence of HIV and associated sociodemographic factors including mobility and migration in a rural population in KwaZulu-Natal, South Africa.

METHODS

A household-based HIV serosurvey of a population that has been under longitudinal demographic surveillance since 2000. All residents (women aged 15-49 years; men aged 15-54 years) and a sample of non-residents ('migrants') who return periodically to their households in the area were identified and approached for finger-prick HIV testing.

RESULTS

A total of 8325/11 505 male and 11 542/14 396 female residents were traced. Of these, 4692 men and 6859 women consented to HIV testing. Overall, 27% of female and 13.5% of male residents were HIV infected. HIV prevalence peaked at 51% among resident women aged 25-29 years and 44% among resident men aged 30-34 years, with the highest infection rates of 57.5% among 26-year-old women. The female: male infection ratio for residents aged 15-19 years was 13.0. Many factors, including increased mobility, associated with an increased risk of HIV infection among residents, were also associated with non-participation. Among non-residents, 34% of men aged 15-54 years and 41% of women aged 15-49 years were HIV infected.

CONCLUSION

The extremely high prevalence of HIV suggests an urgent need to allocate adequate resources for HIV prevention and treatment in rural areas. Effective monitoring of the epidemic in Africa needs to include efforts to strengthen sentinel surveillance in rural areas and strategies for the surveillance of migrants and mobile individuals.

Higher HIV-1 incidence and genetic complexity along main roads in Rakai District, Uganda

OBJECTIVE

To determine the association between the incidence of HIV-1 infection and the genetic complexity of HIV-1 strains in 2 geographic strata within Rakai District, Uganda.

METHODS

Study volunteers with recent HIV-1 infections during the period 1997 through 2003 were recruited from 10 communities that were geographically stratified as a main road trading center (n = 5) or a secondary road trading village (n = 5). Cryopreserved plasma was available from 384 volunteers and was the source of viral RNA for genotyping by the multiregion hybridization assay. Hazard ratios (HRs) for a single HIV subtype, a recombinant form, or dual infection for gender and geographic strata were obtained using Cox proportional hazards analysis.

RESULTS

The HIV-1 incidence rate during the period 1999 through 2002 was 1.3 per 100 person-years (PYs) in the trading centers and 1.1 per 100 PYs in the trading villages. The HR for infection with an HIV-1 recombinant strain in trading centers relative to trading villages was 2.3 (95% confidence interval [CI]: 1.0 to 6.7). Among those who changed residence between village strata, the HR for a recombinant HIV-1 infection was 8.1 (95% CI: 0.4 to 47.7).

CONCLUSIONS

HIV-1 incidence and genetic complexity are associated with geographic strata and population mobility in Rakai District and are important variables to be considered in planning and recruitment for vaccine trials.

Repeat voluntary HIV counseling and testing (VCT), sexual risk behavior and HIV incidence in Rakai, Uganda

We examined the effects of repeat Voluntary HIV counseling and testing (VCT) on sexual risk behaviors and HIV incidence in 6,377 initially HIV-negative subjects enrolled in a prospective STD control for HIV prevention trial in rural Rakai district, southwestern Uganda. Sixty-four percent accepted VCT, and of these, 62.2% were first time acceptors while 37.8% were repeat acceptors. Consistent condom use was 5.8% in repeat acceptors, 6.1% in first time acceptors and 5.1% in non-acceptors. A higher proportion of repeat acceptors (15.9%) reported inconsistent condom use compared to first-time acceptors (12%) and non-acceptors (11.7%). Also, a higher proportion of repeat acceptors (18.1%) reported 2+ sexual partners compared to first-time acceptors (14.1%) and non-acceptors (15%). HIV incidence rates were 1.4/100 py (person-years) in repeat acceptors, 1.6/100 py in first time acceptors and 1.6/100 py in non-acceptors. These data suggest a need for intensive risk-reduction counseling interventions targeting HIV-negative repeat VCT acceptors as a special risk group.

Prevalence of urinary schistosomiasis and HIV in females living in a rural community of Zimbabwe: does age matter?

A cross-sectional study was conducted on 544 women living in Mupfure rural area of Zimbabwe to determine whether infection with urinary schistosomiasis is associated with HIV infection. Schistosoma haematobium infection was examined in urine samples and HIV infection was determined in sera. The prevalence of S. haematobium infection was highest (60%) in women below 20 years of age and declined to 29% in the oldest age group (test for trends, P<0.001). Overall, women infected with urinary schistosomiasis had an HIV prevalence of 33.3%, whilst women without urinary schistosomiasis had an HIV prevalence of 25.6% (chi(2), P=0.053). Women above the age of 35 years and infected with urinary schistosomiasis had a significantly higher HIV prevalence (37.5%) than those without urinary schistosomiasis (16.8%; chi(2), P<0.001).

Association between genital schistosomiasis and HIV in rural Zimbabwean women

OBJECTIVE

To determine the association between female genital Schistosoma haematobium infection and HIV.

DESIGN AND METHODS

A cross-sectional study with a 1-year follow-up. Gynecological and laboratory investigations were performed for S. haematobium and HIV. Sexually transmitted infections, demographic and urogenital history were analysed as confounders. The participants were 527 sexually active, non-pregnant, non-menopausal women between the ages of 20 and 49 years. The setting was a rural Zimbabwean community where S. haematobium related lesions were found in 46% of the women, HIV in 29% and herpes simplex type- 2 (HSV-2) in 65%.

RESULTS

In permanent residents (>3 years residency), HIV was found in 41% (29/70) of women with laboratory proven genital schistosomiasis as opposed to 26% HIV positive (96/375) in the schistosomal ova negative group [odds ratio (OR), 2.1; 95% confidence interval (CI), 1.2-3.5; P = 0.008. In multivariate analysis S. haematobium infection of the genital mucosa was significantly associated with HIV seropositivity (adjusted OR, 2.9; 95% CI, 1.11-7.5; P = 0.030). All seven women who became HIV positive during the study period (seroincidence 3.1%) had signs of S. haematobium at baseline. In accordance with other studies HIV was significantly associated with HSV-2 (OR, 3.0; 95% CI, 1.7-5.3; P < 0.001), syphilis and human papillomavirus. The highest HIV prevalence (45%) was found in the 25-29 years age group.

CONCLUSION

Women with genital schistosomiasis had an almost three-fold risk of having HIV in this rural Zimbabwean community. Prospective studies are needed to confirm the association.

Can population differences explain the contrasting results of the Mwanza, Rakai, and Masaka HIV/sexually transmitted disease intervention trials?: A modeling study

OBJECTIVE

To determine whether population differences can explain the contrasting impacts on HIV observed in the Mwanza trial of sexually transmitted disease (STD) syndromic treatment (ST), the Rakai trial of STD mass treatment (MT), and the Masaka trial of information, education, and communication (IEC) with and without ST as well as to predict the effectiveness of each intervention strategy in each population.

METHODS

Stochastic modeling of the transmission of HIV and 6 STDs was used with parameters fitted to demographic, sexual behavior, and epidemiological data from the trials and general review of STD/HIV biology.

RESULTS

The baseline trial populations could be simulated by assuming higher risk behavior in Uganda compared with Mwanza in the 1980s, followed by reductions in risk behavior in Uganda preceding the trials. In line with trial observations, the projected HIV impacts were larger for the ST intervention in Mwanza than for the MT intervention in Rakai or the IEC and IEC + ST interventions in Masaka. All 4 simulated intervention strategies were more effective in reducing incidence of HIV infection in Mwanza than in either Rakai or Masaka.

CONCLUSIONS

Population differences in sexual behavior, curable STD rates, and HIV epidemic stage can explain most of the contrast in HIV impact observed between the 3 trials. This study supports the hypothesis that STD management is an effective HIV prevention strategy in populations with a high prevalence of curable STDs, particularly in an early HIV epidemic.

Changes in sexual behavior and risk of HIV transmission after antiretroviral therapy and prevention interventions in rural Uganda

BACKGROUND

The impact of antiretroviral therapy (ART) on sexual risk behavior and HIV transmission among HIV-infected persons in Africa is unknown.

OBJECTIVE

To assess changes in risky sexual behavior and estimated HIV transmission from HIV-infected adults after 6 months of ART.

DESIGN AND METHODS

A prospective cohort study was performed in rural Uganda. Between May 2003 and December 2004 a total of 926 HIV-infected adults were enrolled and followed in a home-based ART program that included prevention counselling, voluntary counseling and testing (VCT) for cohabitating partners and condom provision. At baseline and follow-up, participants' HIV plasma viral load and partner-specific sexual behaviors were assessed. Risky sex was defined as inconsistent or no condom use with partners of HIV-negative or unknown serostatus in the previous 3 months. The rates of risky sex were compared using a Poisson regression model and transmission risk per partner was estimated, based on established viral load-specific transmission rates.

RESULTS

Six months after initiating ART, risky sexual behavior reduced by 70% [adjusted risk ratio, 0.3; 95% confidence interval (CI), 0.2-0.7; P = 0.0017]. Over 85% of risky sexual acts occurred within married couples. At baseline, median viral load among those reporting risky sex was 122 500 copies/ml, and at follow-up, < 50 copies/ml. Estimated risk of HIV transmission from cohort members declined by 98%, from 45.7 to 0.9 per 1000 person years.

CONCLUSIONS

Providing ART, prevention counseling, and partner VCT was associated with reduced sexual risk behavior and estimated risk of HIV transmission among HIV-infected Ugandan adults during the first 6 months of therapy. Integrated ART and prevention programs may reduce HIV transmission in Africa.