Is concurrency driving HIV transmission in sub-Saharan African sexual networks? The significance of sexual partnership typology.

Recently, there has been debate about the role of concurrent partnerships in driving the transmission of HIV, particularly in Southern Africa, where HIV prevalence is up to 25 % in many heterosexual populations and where evidence from sexual behavior surveys also suggests high levels of male concurrency. While mathematical modeling studies have shown that concurrency has the potential to enhance the speed at which HIV spreads in a population, empirical studies up to now have failed to provide conclusive evidence supportive of these effects. Here we discuss some reasons for the apparent discrepancy between theoretical and empirical studies. We propose that studying the impact of concurrency on HIV transmission should be differentiated by taking more insight from social and behavioral studies on sexual partnerships into account. We also suggest that a more rigorous definition is needed for when a factor is considered a driving force for HIV epidemic spread. We illustrate this with a modeling example.

Promotion of couples' voluntary counselling and testing for HIV through influential networks in two African capital cities.

BACKGROUND: Most new HIV infections in Africa are acquired from cohabiting heterosexual partners. Couples' Voluntary Counselling and Testing (CVCT) is an effective prevention strategy for this group. We present our experience with a community-based program for the promotion of CVCT in Kigali, Rwanda and Lusaka, Zambia. METHODS: Influence Network Agents (INAs) from the health, religious, non-governmental, and private sectors were trained to invite couples for CVCT. Predictors of successful promotion were identified using a multi-level hierarchical analysis. RESULTS: In 4 months, 9,900 invitations were distributed by 61 INAs, with 1,411 (14.3%) couples requesting CVCT. INAs in Rwanda distributed fewer invitations (2,680 vs. 7,220) and had higher response rates (26.9% vs. 9.6%), than INAs in Zambia. Context of the invitation event, including a discreet location such as the INA's home (OR 3.3-3.4), delivery of the invitation to both partners in the couple (OR 1.6-1.7) or to someone known to the INA (OR 1.7-1.8), and use of public endorsement (OR 1.7-1.8) were stronger predictors of success than INA or couple-level characteristics. CONCLUSION: Predictors of successful CVCT promotion included strategies that can be easily implemented in Africa. As new resources become available for Africans with HIV, CVCT should be broadly implemented as a point of entry for prevention, care and support.

Study of bias in antenatal clinic HIV-1 surveillance data in a high contraceptive prevalence population in sub-Saharan Africa.

OBJECTIVE: To describe patterns, sources and consequences of bias in antenatal clinic (ANC) HIV prevalence estimates in a high contraceptive prevalence population. BACKGROUND: HIV surveillance in Africa relies on data from pregnant women attending ANCs. HIV estimates from pregnant women understate female infection levels in low income, high fertility populations. Bias in high contraceptive use, delayed sexual debut populations remains undescribed. DESIGN AND METHOD: Comparison of parallel cross-sectional population and antenatal survey data from rural Zimbabwe, where 60% of women are recent contraceptive users. RESULTS: HIV prevalence in recently pregnant women (25.7%; n = 576) and all women (25.5%; n = 5138) is similar over the age-range 15-44 years. As in high fertility populations, HIV prevalence is higher in pregnant women at young ages and lower at older ages but the crossover point occurs later due to delayed sexual activity. HIV understatement at older ages due to HIV-associated infertility is mitigated by less HIV infection and less frequent ANC attendance in contraceptive users. The local ANC HIV prevalence estimate is lower [21.2%; n = 1215; risk ratio versus pregnant women in the general population, 0.8; 95% confidence interval (CI), 0.7-1.0], possibly because women from more remote areas are included. ANC estimates overstate the relative risk of HIV in more educated women (age-adjusted odds ratio, 1.1; 95% CI, 0.8-1.4 versus 0.7; 95% CI, 0.6-0.9). CONCLUSIONS: ANC estimates understate female HIV prevalence in this low fertility population but, here, the primary cause is not selection of pregnant women. ANC estimate adjustment procedures that control for contraceptive use and age at first sex are needed.

Changing patterns of knowledge, reported behaviour and sexually transmitted infections in a South African gold mining community.

BACKGROUND: In 1998, a major HIV intervention project was started in a mining community in Carletonville, South Africa. This included community-based peer education, condom distribution, syndromic management of sexually transmitted infections (STI), and presumptive STI treatment for sex workers. OBJECTIVES: To investigate changes in sexual behaviour and the prevalence of STI before and 2 years after the start of the HIV prevention programme. METHODS: Cross-sectional surveys were carried out in 1998 and 2000 among mine workers, sex workers and adults in the community. Demographic and behavioural factors were recorded and participants were tested for syphilis, gonorrhoea and chlamydial infection and, at the start of the intervention, for HIV. RESULTS: In 1998, the prevalence of HIV among men and women in the general population, mine workers, and sex workers, was 20%, 37%, 29% and 69%, respectively. In 2000, syphilis, gonorrhoea and chlamydial infection had increased among mine workers; chlamydial infection had increased among men and women, and syphilis had increased among women. There was evidence of positive behaviour change but this was not substantial or universal. Knowledge of HIV/AIDS and awareness of the epidemic were high but condom use remained low. CONCLUSION: There was little evidence of significant behaviour change and the prevalence of curable STI increased. The prevention programme had had less impact than expected. Reasons for the reduced impact, and the lessons for future intervention projects are discussed. There is a need for further monitoring of the HIV epidemic especially as its impact increases.

Increase in condom use and decline in HIV and sexually transmitted diseases among female sex workers in Abidjan, Côte d'Ivoire, 1991-1998.

OBJECTIVE: To assess clinic- and community-based trends in demographic and behavioral characteristics and clinic-based trends in HIV infection and other sexually transmitted diseases (STD) in female sex workers in Abidjan, Côte d'Ivoire. DESIGN: Multiyear cross-sectional study of first-time attenders in Clinique de Confiance, a confidential STD clinic; biannual community-based behavioral surveys. METHODS: From 1992 to 1998, female sex workers were invited to attend Clinique de Confiance, where they were counseled, interviewed, clinically examined during their first visit and tested for STD and HIV infection. Community-based surveys, conducted in 1991, 1993, 1995, and 1997, interviewed women regarding socio-demographic characteristics and HIV/STD-related knowledge, attitudes and behavior. RESULTS: Among female sex workers in Abidjan, there was a trend toward shorter duration of sex work, higher prices, and more condom use. Among sex workers attending Clinique de Confiance for the first time, significant declines were found in the prevalence of HIV infection (from 89 to 32%), gonorrhoea (from 33 to 11%), genital ulcers (from 21 to 4%), and syphilis (from 21 to 2%). In a logistic regression model that controlled for socio-demographic and behavioral changes, the year of screening remained significantly associated with HIV infection. CONCLUSION: The increase in condom use and the decline in prevalence of HIV infection and other STD may well have resulted from the prevention campaign for female sex workers, and such campaigns should therefore be continued, strengthened, and expanded.

Epidemiology of HIV infection in urban Burkina Faso.

We conducted a cross-sectional study of sexually transmitted disease and HIV infections among a random sample of the 2364 adult population in 2000 in Bobo-Dioulasso, the second largest town in Burkina Faso. The prevalence of HIV infection was 5.2%. Risk factor analysis was conducted among sexually active men 20 to 34 years old and women 15 to 24 years old. Factors independently associated with HIV infection among men were having been married (adjusted odds ratio (aOR)=8.19 [1.70-39]), reporting more than two non-marital partners in the last 12 months (aOR=6.07 [1.14-32.4]), reporting a past urban residence other than Bobo-Dioulasso (aOR =6.37 [1.96-20.7] and having a positive serology for HSV-2 infection (aOR=12.0 [3.49-40.9]). Among women the factors were being Christian (aOR=3.73 [1.20-11.6]), having had a first sexual partner more than 24 years old (aOR =4.30 [1.35-13.6]) and having a positive serology for HSV-2 infection (aOR =4.40 [1.32-14.6]). HIV infection in Bobo-Dioulasso therefore depends on both exposure factors (sexual behaviours) and transmissibility cofactors (HSV-2).

Knowledge and perceptions of couples' voluntary counseling and testing in urban Rwanda and Zambia: a cross-sectional household survey.

BACKGROUND: Most incident HIV infections in sub-Saharan Africa occur between cohabiting, discordant, heterosexual couples. Though couples' voluntary HIV counseling and testing (CVCT) is an effective, well-studied intervention in Africa, <1% of couples have been jointly tested. METHODS: We conducted cross-sectional household surveys in Kigali, Rwanda (n = 600) and Lusaka, Zambia (n = 603) to ascertain knowledge, perceptions, and barriers to use of CVCT. RESULTS: Compared to Lusaka, Kigali respondents were significantly more aware of HIV testing sites (79% vs. 56%); had greater knowledge of HIV serodiscordance between couples (83% vs. 43%); believed CVCT is good (96% vs. 72%); and were willing to test jointly (91% vs. 47%). Stigma, fear of partner reaction, and distance/cost/logistics were CVCT barriers. CONCLUSIONS: Though most respondents had positive attitudes toward CVCT, the majority were unaware that serodiscordance between cohabiting couples is possible. Future messages should target gaps in knowledge about serodiscordance, provide logistical information about CVCT services, and aim to reduce stigma and fear.

AIDS in Asia amid competing priorities: a review of national responses to HIV.

INTRODUCTION: The paper reviews progress in addressing the HIV epidemic and questions whether at the midway mark to the conclusion of the Millennium Development Goal set for 2015, the goal number 6 of halting and reversing the HIV epidemic will be reached. METHODS: Fourteen 2008 United Nations General Assembly Special Session on HIV/AIDS country progress reports and 18 country reports on Universal Access 2009 were analyzed. Data on national HIV strategic plans was also provided by 18 countries that participated in the regional training on costed national strategic plans 15-16 September, in Bangkok in 2008. RESULTS: Four countries with substantial populations in Asia are on track to achieve Millennium Development Goal 6. Elsewhere, elements of a potentially effective response are being introduced, but the degree of urgency and scale needed to curb the epidemics are not yet evident. Most national programmes still lack key planning components for the operation and financing of the response. Only 13 national strategic plans explicitly address the three key populations at higher risk for HIV. One third of the countries that have designed plans for effective interventions have not costed them. DISCUSSION: Early successes in controlling HIV epidemics in Asia may not be sustainable in the future. There is an urgent need to make prevention scale-up as robust as treatment scale-up and to focus programmes on high impact prevention, which directly contributes to reduction of new HIV infection. A necessary objective is to convince policy makers that the emergency posed by HIV continues.

Is there a gender gap in the HIV response? Evaluating national HIV responses from the United Nations General Assembly Special Session on HIV/AIDS country reports.

BACKGROUND: The Declaration of Commitment of the United Nations General Assembly Special Session on HIV/AIDS (UNGASS), in 2001, sets out several policy and programmatic commitments that pertain to women and the gender aspects of the HIV epidemic. Some of them are general, whereas others are more specific and include time-bounded targets. This article summarizes data on policies and strategies affecting women and men equity in access to antiretroviral treatment and other HIV services, as reported by countries but do not address other issues of gender, such as men having sex with men. METHODS: The analysis includes data from the National Composite Policy Index as reported by 130 countries in response to 14 questions relating to progress in creating an enabling policy environment for women. Additional data on gender equity in knowledge of HIV and access to HIV testing and antiretroviral treatment is obtained with other core UNGASS indicators. The review aggregates countries according to regions. RESULTS: A total of 147 countries provided national reports in which 78% of relevant UNGASS indicators were either completely or partially disaggregated by sex. However, 16% of countries did not report any HIV indicators by sex (with a range of 0%-29% across regions). A total of 82% (108 of 130) of countries report having policies in place to ensure that women have equal access to HIV-related services, but 14% of reporting countries also had laws and policies in place that hinder their ability to deliver effective HIV programs for women. About 80% of countries report having included women as a specific "sector" in their multisectoral AIDS strategies or action frameworks. However, only slightly more than half (53%) of those countries report having a budget attached to programs addressing women issues. As of the end of 2007, antiretroviral therapy reached 33% of people in need, and women represent a slight majority of those on treatment. The gender gap on HIV knowledge has narrowed, but overall levels of knowledge on how to prevent HIV remains at low levels, with only about 40% of young men (aged 15-24 years) and 36% of young women with correct comprehensive knowledge about HIV prevention. CONCLUSIONS: Since 2001, a large majority of countries have integrated women-related issues into their national HIV policies and strategic plans. However, countries and regions with low-level or concentrated HIV epidemics lag behind countries with generalized epidemics in integrating women-focused policies into national frameworks. The lack of budget support for women-focused programs in half of the countries indicates that those policies have not been sufficiently translated into multisectoral activities. The engagement of development ministries in women's social and economic empowerment is largely still lacking, which raises the concern that strategies to reduce gender inequality may also be lacking in broader development plans. The apparent attainment of gender equity in HIV testing and the delivery of antiretroviral treatment is an important achievement. There has also been a significant increase in countries' abilities to collect and report data disaggregated by sex and age. The monitoring of women's progress in HIV responses via the UNGASS reporting system provides important insights but should be complemented with data that strengthen understandings of the actual implementation of strategies, as well.

Are we on course for reporting on the Millennium Development Goals in 2015?

OBJECTIVES: At the 2001 United Nations General Assembly Special Session on HIV/AIDS (UNGASS), Member States agreed to regularly review progress made in national responses to HIV. This article provides (1) a brief overview of how the resultant global UNGASS reporting system was developed; (2) the origins, background, limitations and potential of that system; (3) an overview of the articles in this supplement; and (4) crosscutting institutional and methodological issues. METHODS: United Nations Member States biennially provide The Joint United Nations Programme on HIV/AIDS (UNAIDS) with data on 25 core indicators of national responses to HIV, collected in Country Progress Reports. This article critically reviews and interprets these data in light of international political considerations and overall data needs. RESULTS: There has been a considerable improvement in response rates, accompanied by an increase in data quality and completeness. Both nationally and internationally, the UNGASS process is viewed as being more substantial and important than a reporting exercise to the United Nations General Assembly. The process has catalyzed the development of national monitoring systems and has created opportunities for civil society to monitor and challenge government commitments and deeds. CONCLUSIONS: Although the UNGASS global reporting system now comprises an unequaled wealth of data on HIV responses, collected from a broad range of countries, it cannot yet answer several critical questions about the progress and effectiveness of those responses. Evaluation studies that go beyond indicator monitoring are needed, but they will take time to design, fund, implement and interpret. In the meantime, this global monitoring system provides a good indication of the overall progress in the global response to HIV and whether Millennium Development Goal (MDG) 6 (to halt and reverse the HIV epidemic) is likely to be reached by 2015.

How Uganda reversed its HIV epidemic.

Uganda is one of only two countries in the world that has successfully reversed the course of its HIV epidemic. There remains much controversy about how Uganda's HIV prevalence declined in the 1990s. This article describes the prevention programs and activities that were implemented in Uganda during critical years in its HIV epidemic, 1987 to 1994. Multiple resources were aggregated to fuel HV prevention campaigns at multiple levels to a far greater degree than in neighboring countries. We conclude that the reversed direction of the HIV epidemic in Uganda was the direct result of these interventions and that other countries in the developing world could similarly prevent or reverse the escalation of HIV epidemics with greater availability of HIV prevention resources, and well designed programs that take efforts to a critical breadth and depth of effort.

Can highly active antiretroviral therapy reduce the spread of HIV?: A study in a township of South Africa.

BACKGROUND: Calls have been made for the large-scale delivery of highly active antiretroviral therapy (HAART) to people infected with HIV in developing countries. If this is to be done, estimates of the number of people who currently require HAART in high HIV prevalence areas of sub-Saharan Africa are needed, and the impact of the widespread use of HAART on the transmission and, hence, spread of HIV must be assessed. OBJECTIVES: To estimate the proportion of people eligible for combination antiretroviral therapy and to evaluate the potential impact of providing HAART on the spread of HIV-1 under World Health Organization (WHO) guidelines in a South African township with a high prevalence of HIV-1. DESIGN: A community-based cross-sectional study in a township near Johannesburg, South Africa, of a random sample of approximately 1000 men and women aged 15 to 49 years. METHODS: Background characteristics and sexual behavior were recorded by questionnaire. Participants were tested for HIV-1, and their CD4 cell counts and plasma HIV-1 RNA loads were measured. The proportion of people whose CD4 cell count was less than 200 cells/mm and who would be eligible to receive HAART under WHO guidelines was estimated. The potential impact of antiretroviral drugs on the spread of HIV-1 in this setting was determined by estimating among the partnerships engaged in by HIV-1-positive individuals the proportion of spousal and nonspousal partnerships eligible to receive HAART and then by calculating the potential impact of HAART on the annual risk of HIV-1 transmission due to sexual contacts with HIV-1-infected persons. The results were compared with those obtained using United States Department of Health and Human Services (USDHHS) guidelines. RESULTS: The overall prevalence of HIV-1 infection was 21.8% (19.2%-24.6%), and of these people, 9.5% (6.1%-14.9%) or 2.1% (1.3%-3.3%) of all those aged 15 to 49 years would be eligible for HAART (ranges are 95% confidence limits). In each of the next 3 years 6.3% (4.6%-8.4%) of those currently infected with HIV-1 need to start HAART. Among the partnerships in which individuals were HIV-1-positive, only a small proportion of spousal partnerships (7.6% [3.4%-15.6%]) and nonspousal partnerships (5.7%, [3.0%-10.2%]) involved a partner with a CD4 cell count below 200 cells/mm and would have benefited from the reduction of transmission due to the decrease in plasma HIV-1 RNA load under HAART. Estimates of the impact of HAART on the annual risk of HIV-1 transmission show that this risk would be reduced by 11.9% (7.1%-17.0%). When using USDHHS guidelines, the proportion of HIV-1-positive individuals eligible for HAART reached 56.3% (49.1%-63.2%) and the impact of HAART on the annual risk of HIV-1 transmission reached 71.8% (64.5%-77.5%). CONCLUSIONS: The population impact of HAART on reducing sexual transmission of HIV-1 is likely to be small under WHO guidelines, and reducing the spread of HIV-1 will depend on further strengthening of conventional prevention efforts. A much higher impact of HAART is to be expected if USDHHS guidelines are used.

HIV risk in relation to marriage in areas with high prevalence of HIV infection.

In sub-Saharan Africa, the prevalence of HIV infection among young women is much higher than that among young men. Many women enter marriage HIV-infected, suggesting that men may be predominantly infected by their wives. Using data from cross-sectional surveys in Kisumu, Kenya, and Ndola, Zambia, in 1997, the prevalence of HIV infection at marriage was estimated from age at marriage and age- and sex-specific prevalence of HIV infection among unmarried individuals. Using a deterministic model, this prevalence was compared with measured concordance of HIV infection among recently married couples to estimate transmission probabilities within marriage and extramarital incidence of HIV infection. Over a wide range of assumptions, we estimated that at least one quarter of cases of HIV infection in recently married men were acquired from extramarital partnerships, and for both men and women, less than one half of cases of HIV infection were acquired from their spouse. In these sites, many infections in married men, even in those with HIV-infected wives, may be acquired from outside the marriage.

Does increased general schooling protect against HIV infection? A study in four African cities.

BACKGROUND: The association between educational attainment and risk of HIV infection varies between populations and over time. Earlier studies in sub-Saharan Africa have found that those with more education are at increased risk of HIV infection. METHODS: We investigated the associations between general schooling and both HIV and herpes simplex-2 (HSV-2) infection using data from the multicentre study on factors determining the differential spread of HIV in four African cities. Cross-sectional general population studies were conducted in 1997-1998 in Cotonou (Benin), Yaoundé (Cameroon), Kisumu (Kenya), and Ndola (Zambia), including about 2000 adults in each city. RESULTS: There was no association between schooling and HIV infection in men or women in Kisumu or Ndola. Women in Yaoundé and men in Cotonou, with more schooling, were less likely to be HIV positive. These associations persisted after adjusting for sociodemographic factors. Similar trends in men in Yaoundé and women in Cotonou were not statistically significant. Increased schooling was associated with significantly decreased risk of HSV-2 infection in women in Kisumu and Ndola and men in Cotonou. In all the cities those with more education tended to report less risky sexual behaviour. CONCLUSIONS: There was no evidence of an increased risk of HIV infection associated with education as seen in earlier studies. In each city there was some evidence of lower HIV or HSV-2 infection rates and less risky sexual behaviour associated with increased education levels. The most educated may be responding more readily to health education programmes. The challenge is to extend this to the rest of the population.

Sexual mixing patterns and sex-differentials in teenage exposure to HIV infection in rural Zimbabwe.

BACKGROUND: HIV-1 prevalence typically rises more rapidly at young ages in women than in men in sub-Saharan Africa. Greater susceptibility to infection on exposure in women is believed to be a contributory factor as is greater exposure to previously infected sexual partners of the opposite sex. We investigated the latter hypothesis using data from a field study in rural Manicaland, Zimbabwe. METHODS: Quantitative data on onset and degree of sexual activity, numbers of partners, concurrent partnerships, condom use, and partner characteristics were used in conjunction with epidemiological data on age and sex specific prevalence of HIV infection to do statistical analyses of association between key variables. Mathematical models and qualitative data were used to aid analysis and interpretation. FINDINGS: Older age of sexual partner was associated with increased risk of HIV-1 infection in men (odds ratio 1.13 [95% CI 1.02-1.25]) and women (1.04 [1.01-1.07]). Young women form partnerships with men 5-10 years older than themselves, whereas young men have relationships with women of a similar age or slightly younger. Greater number of lifetime partners is also associated with increased risk of HIV (1.03 [1.00-1.05]). Young men report more partners than do women but infrequent coital acts and greater use of condoms. These behaviour patterns are underpinned by cultural factors including the expectation that women should marry earlier than men. A strong gender effect remains after factors that affect exposure to infected partners are controlled for (6.04 [1.49-24.47]). INTERPRETATION: The substantial age difference between female and male sexual partners in Manicaland is the major behavioural determinant of the more rapid rise in HIV prevalence in young women than in men. Theoretical studies have suggested that this difference is an important determinant of observed epidemiological patterns but the study reported in this paper provides clear empirical evidence of association.