Reductions in risk behaviour provide the most consistent explanation for declining HIV-1 prevalence in Uganda

Systematic review and meta-analysis of seroprevalence of human immunodeficiency virus serological markers among pregnant women in Africa, 1984-2020

BACKGROUND

Human immunodeficiency virus (HIV) is a major public health concern, particularly in Africa where HIV rates remain substantial. Pregnant women are at an increased risk of acquiring HIV, which has a significant impact on both maternal and child health.

AIM

To review summarizes HIV seroprevalence among pregnant women in Africa. It also identifies regional and clinical characteristics that contribute to study-specific estimates variation.

METHODS

The study included pregnant women from any African country or region, irrespective of their symptoms, and any study design conducted in any setting. Using electronic literature searches, articles published until February 2023 were reviewed. The quality of the included studies was evaluated. The DerSimonian and Laird random-effects model was applied to determine HIV pooled seroprevalence among pregnant women in Africa. Subgroup and sensitivity analyses were conducted to identify potential sources of heterogeneity. Heterogeneity was assessed with Cochran's Q test and I2 statistics, and publication bias was assessed with Egger's test.

RESULTS

A total of 248 studies conducted between 1984 and 2020 were included in the quantitative synthesis (meta-analysis). Out of the total studies, 146 (58.9%) had a low risk of bias and 102 (41.1%) had a moderate risk of bias. No HIV-positive pregnant women died in the included studies. The overall HIV seroprevalence in pregnant women was estimated to be 9.3% [95% confidence interval (CI): 8.3-10.3]. The subgroup analysis showed statistically significant heterogeneity across subgroups (P < 0.001), with the highest seroprevalence observed in Southern Africa (29.4%, 95%CI: 26.5-32.4) and the lowest seroprevalence observed in Northern Africa (0.7%, 95%CI: 0.3-1.3).

CONCLUSION

The review found that HIV seroprevalence among pregnant women in African countries remains significant, particularly in Southern African countries. This review can inform the development of targeted public health interventions to address high HIV seroprevalence in pregnant women in African countries.

Epidemiology of herpes simplex virus type 2 in Europe: systematic review, meta-analyses, and meta-regressions

Background

Herpes simplex virus type 2 (HSV-2) infection is a globally prevalent, life-long, sexually transmitted infection. This study characterized HSV-2 seroprevalence in Europe for various at-risk populations and proportions of HSV-2 detection in genital ulcer disease (GUD) and in genital herpes. Data on neonatal herpes and HSV-2's contribution to HIV transmission were also reviewed.

Methods

Cochrane and PRISMA guidelines were followed to systematically review, synthesize, and report HSV-2 related findings. The search was conducted in PubMed and Embase databases up to February 20, 2022. Any publication reporting data on the outcome measures was included. Meta-analyses and meta-regressions were conducted.

Findings

211 relevant reports were identified, including 12 overall incidence measures, 294 overall (813 stratified by factors such as age and sex) seroprevalence measures, 13 overall (15 stratified by sex) proportions of HSV-2 detection in clinically diagnosed GUD, and 70 overall (183 stratified by factors such as age and sex) proportions of HSV-2 detection in laboratory-confirmed genital herpes. Pooled mean seroprevalence was 12.4% (95% CI: 11.5-13.3%) among general populations, 27.8% (95% CI: 17.5-39.4%) among men who have sex with men, 46.0% (95% CI: 40.1-51.8%) among people living with HIV and people in HIV discordant couples, and 63.2% (95% CI: 55.5-70.6%) among female sex workers. Most measures showed heterogeneity in HSV-2 seroprevalence. The pooled mean seroprevalence among general populations increased with age and was 0.65-fold (95% CI: 0.58-0.74) lower in men than women. Seroprevalence decreased by 1% per calendar year. Pooled mean proportions of HSV-2 detection in GUD and in genital herpes were 22.0% (95% CI: 15.3-29.6%) and 66.0% (95% CI: 62.9-69.1%), respectively. HSV-2 detection in genital herpes cases was 1.21-fold (95% CI: 1.10-1.32) higher in men compared to women and decreased by 1% per calendar year. Incidence of neonatal herpes indicated an increasing trend.

Interpretation

Although seroprevalence is declining, a significant proportion of Europe's population is infected with HSV-2. HSV-2 accounts for approximately one-fifth of GUD cases and two-thirds of genital herpes cases. Findings support the need to invest in HSV-2 vaccine development, and sexual and reproductive health services.

Funding

Qatar National Research Fund [NPRP 9-040-3-008] and pilot funding from the Biomedical Research Program at Weill Cornell Medicine in Qatar supported this study.

A Comparative Study of the Epidemiology of Treponemal Infection in the Volta and Oti Regions of Ghana: A Five-Year Multisite Parallel Population-Based Analysis vis-à-vis the Sentinel Survey

Treponemal infections can be blood-borne with great public health consequences. This study is aimed at comparatively describing the five-year (2013-2017) regional epidemiology of treponemal infection using pregnant women in the sentinel survey and apparently healthy blood donors as a proxy for the general population at four sentinel sites in the Volta and Oti Regions of Ghana. We analyzed retrospective data from 17,744 prospective blood donors aged 18 to 58 years and 7,817 pregnant women in a sentinel survey with ages from 15 to 49 years at Hohoe, Ho, Tongu, and Krachi West sentinel sites in the Volta and Oti Regions. Laboratory data extracted include variables such as age, gender, date of blood donation, and Treponema pallidum chromatographic immunoassay results from the blood banks of the four study sites. The five-year treponemal infection rate among the pregnant women in the sentinel survey and prospective blood donors was 0.79% and 2.38%, respectively. Site-specific infection rate for population-based/sentinel survey was 4.6%/1.1%, 2.0%/0.5%, 1.3%/1.1, and 1.2%/0.3% for Hohoe, Ho, Krachi West, and Tongu, respectively. Significant gender disparity in Treponemal infection rate exists with a male preponderance. The regional infection rate in the sentinel survey is lower compared to the general population. Therefore, the use of pregnant women as a proxy for population estimates could underestimate the burden in the study jurisdiction.

Epidemiology of herpes simplex virus type 2 in Asia: A systematic review, meta-analysis, and meta-regression

Background

Herpes simplex virus type 2 (HSV-2) infection is a prevalent sexually transmitted infection worldwide. This systematic review was conducted to characterize HSV-2 epidemiology in Asia, including the World Health Organization regions of Southeast Asia and the Western Pacific.

Methods

Cochrane and PRISMA guidelines were followed to systematically review and report findings. Pooled mean seroprevalence and proportions of HSV-2 isolated in genital ulcer disease (GUD) and in genital herpes were calculated using random-effects meta-analyses. Meta-regressions were also conducted. Quality assessment was performed.

Findings

HSV-2 measures extracted from 173 publications included 15 seroconversion rates, 11 seroincidence rates, 272 overall seroprevalence measures (678 stratified), 14 proportions of HSV-2 isolation in GUD (15 stratified), and 27 proportions of HSV-2 isolation in genital herpes (36 stratified). Pooled mean seroprevalence was 12.1% (95% confidence interval (CI): 11.0-13.2%) among general populations, 23.6% (95% CI: 20.9-26.3%) among men who have sex with men and transgender people, 46.0% (95% CI: 39.2-52.9%) among HIV-positive individuals and individuals in HIV-discordant couples, and 62.2% (95% CI: 58.9-65.6%) among female sex workers. Among general populations, pooled mean seroprevalence increased gradually from 4.7% (95% CI: 3.3-6.3%) in <20-year-old individuals to 26.6% (95% CI: 19.2-34.7%) in >60-year-old individuals. Compared to women and across all populations, men had 0.60-fold (95% CI: 54.0-67.0) lower seroprevalence, that is women had 70% higher seroprevalence. Seroprevalence declined by 0.98-fold (95% CI: 0.97-0.99) per year, that is a 2% decline per year in the last three decades. Pooled mean proportions of HSV-2 isolation in GUD and in genital herpes were 48.2% (95% CI: 34.9-61.6%) and 75.9% (95% CI: 68.3-82.8%), respectively.

Interpretation

Over 1 in 10 individuals is infected with HSV-2, but seroprevalence is declining. HSV-2 accounts for half of GUD cases and three-quarters of genital herpes cases. These findings support the need for an HSV-2 vaccine and universal access to sexual and reproductive health services.

Funding

This work was supported by the Qatar National Research Fund [NPRP 9-040-3-008] and by pilot funding from the Biomedical Research Program at Weill Cornell Medicine in Qatar.

Epidemiological risk factors associated with primary infection by Epstein-Barr virus in HIV-1-positive subjects in the Brazilian Amazon region

To identify the prevalence and risk factors for primary Epstein–Barr virus (EBV) infection in human immunodeficiency virus (HIV)-1-positive adult treatment-naïve patients between January 2018 and December 2019 in a state of the Brazilian Amazon region. A total of 268 HIV-1 positive patients and 65 blood donors participated in the study. Epidemiological data were obtained from medical records and through a designed questionnaire. EBV infection was screened by the semiquantitative detection of anti-viral capsid antigen (VCA) EBV IgM and IgG, followed by molecular detection of the EBNA-3C gene. The plasma viral loads of HIV-1 and EBV were quantified using a commercial kit. The prevalence of primary coinfection was 7.12%. The associated risk factors were education level, family income, history of illicit drug use and sexually transmitted infections, homosexual contact and condom nonuse. Approximately 58.5% had late initiation of highly active antiretroviral therapy, which influenced the risk of HIV-EBV 1/2 multiple infection (odds ratio (OR): 4.76; 95% CI 1.51–15.04) and symptom development (p = 0.004). HIV viral load was associated with patient age (OR: 2.04; 95% CI 2.01–2.07; p = 0.026) and duration of illicit drug use (OR: 1.57; 95% CI 1.12–2.22; p = 0.0548). EBV viral load was associated with younger age (OR: 0.82; 95% CI 0.79–1.03; p = 0.0579). The replication of both viruses was associated with symptom development (HIV = OR: 2.06; 95% CI 1.22–3.50; p = 0.0073; EBV = OR: 8.81; 95% CI 1–10; p = 0.0447). The prevalence of HIV/EBV coinfection was lower than that observed in other studies, and social vulnerability and promiscuous sexual behavior were associated risk factors. A long time of HIV-1 infection, without therapy, influenced the risk of coinfection and disease progression. The viral loads of both viruses may be associated with some epidemiological aspects of the population.

Epidemiology of herpes simplex virus type 2 in Latin America and the Caribbean: systematic review, meta-analyses and metaregressions

Objective

To characterise epidemiology of herpes simplex virus type 2 (HSV-2) in Latin America and the Caribbean.

Methods

HSV-2 reports were systematically reviewed and synthesised, and findings were reported following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Meta-analyses and metaregressions were conducted.

Finding

102 relevant reports were identified including 13 overall incidence measures, 163 overall (and 402 stratified) seroprevalence measures, and 7 and 10 proportions of virus detection in genital ulcer disease and in genital herpes, respectively. Pooled mean seroprevalence was 20.6% (95% CI 18.7% to 22.5%) in general populations, 33.3% (95% CI 26.0% to 41.0%) in intermediate-risk populations, 74.8% (95% CI 70.6% to 78.8%) in female sex workers, and 54.6% (95% CI 47.4% to 61.7%) in male sex workers, men who have sex with men and transgender people. In general populations, seroprevalence increased from 9.6% (95% CI 7.1% to 12.4%) in those aged <20 years to 17.9% (95% CI 13.6% to 22.5%) in those aged 20–30, 27.6% (95% CI 21.4% to 34.2%) in those aged 30–40 and 38.4% (95% CI 32.8% to 44.2%) in those aged >40. Compared with women, men had lower seroprevalence with an adjusted risk ratio (ARR) of 0.68 (95% CI 0.60 to 0.76). Seroprevalence declined by 2% per year over the last three decades (ARR of 0.98, 95% CI 0.97 to 0.99). Pooled mean proportions of HSV-2 detection in GUD and genital herpes were 41.4% (95% CI 18.9% to 67.0%) and 91.1% (95% CI 82.7% to 97.2%), respectively.

Conclusions

One in five adults is HSV-2 infected, a higher level than other world regions, but seroprevalence is declining. Despite this decline, HSV-2 persists as the aetiological cause of nearly half of GUD cases and almost all of genital herpes cases.

Epidemiology of herpes simplex virus type 2 in sub-Saharan Africa: Systematic review, meta-analyses, and meta-regressions

BACKGROUND

Herpes simplex virus type 2 (HSV-2) infection is a prevalent, sexually transmitted infection with a sizable disease burden that is highest in sub-Saharan Africa. This study aimed to characterize HSV-2 epidemiology in this region.

METHODS

Cochrane and PRISMA guidelines were followed to systematically review, synthesize, and report HSV-2 related findings up to August 23, 2020. Meta-analyses and meta-regressions were conducted.

FINDINGS

From 218 relevant publications, 451 overall outcome measures and 869 stratified measures were extracted. Pooled incidence rates ranged between 2.4-19.4 per 100 person-years across populations. Pooled seroprevalence was lowest at 37.3% (95% confidence interval (CI): 34.9-39.7%) in general populations and high in female sex workers and HIV-positive individuals at 62.5% (95% CI: 54.8-70.0%) and 71.3% (95% CI: 66.5-75.9%), respectively. In general populations, pooled seroprevalence increased steadily with age. Compared to women, men had a lower seroprevalence with an adjusted risk ratio (ARR) of 0.61 (95% CI: 0.56-0.67). Seroprevalence has decreased in recent decades with an ARR of 0.98 (95% CI: 0.97-0.99) per year. Seroprevalence was highest in Eastern and Southern Africa. Pooled HSV-2 proportion in genital ulcer disease was 50.7% (95% CI: 44.7-56.8%) and in genital herpes it was 97.3% (95% CI: 84.4-100%).

INTERPRETATION

Seroprevalence is declining by 2% per year, but a third of the population is infected. Age and geography play profound roles in HSV-2 epidemiology. Temporal declines and geographic distribution of HSV-2 seroprevalence mirror that of HIV prevalence, suggesting sexual risk behavior has been declining for three decades. HSV-2 is the etiological cause of half of genital ulcer disease and nearly all genital herpes cases with limited role for HSV-1.

FUNDING

This work was supported by pilot funding from the Biomedical Research Program at Weill Cornell Medicine in Qatar and by the Qatar National Research Fund [NPRP 9-040-3-008].

Persistence of traditional and emergence of new structural drivers and factors for the HIV epidemic in rural Uganda; A qualitative study

BACKGROUND

In Uganda, the HIV epidemic is now mature and generalized. Recently, there have been reports of resurgence in the incidence of HIV after several years of successful control. The causes for this resurgence are not clear but suspected to be driven by structural factors that influence large groups of people rather than individuals. The aim of this study was to describe the structural drivers of the HIV epidemic in high prevalence regions and inform the next generation of interventions.

METHODOLOGY

We conducted a total of 35 focus group discussions in 11 districts in Uganda. Due to their high HIV prevalence, the districts had been selected to implement a donor supported program to scale up HIV prevention, care and treatment. Focus groups consisted of men and women including opinion leaders, civil servants including teachers, police officers, religious, political leaders, shop keepers, local residents and other ordinary persons from all walks of life. The qualitative data were transcribed and analyzed manually. Texts were coded using a coding scheme which was prepared ahead of time but emerging themes and codes were also allowed.

RESULTS

Our data indicated there is persistence of several structural drivers and factors for HIV in rural Uganda. The structural drivers of HIV were divided into three categories: Gender issues, socio-cultural, and economic drivers. The specific drivers included several gender issues, stigma surrounding illness, traditional medical practices, urbanization, alcohol and substance abuse and poverty. New drivers arising from urbanization, easy access to mobile phone, internet and technological advancement have emerged. These drivers are intertwined within an existing culture, lifestyle and the mixture is influenced by modernization.

CONCLUSION

The traditional structural drivers of HIV have persisted since the emergence of the HIV epidemic in Uganda and new ones have emerged. All these drivers may require combined structural interventions that are culturally and locally adapted in order to tackle the resurgence in incidence of HIV in Uganda.

Relationship between socioeconomic status and HIV infection: findings from a survey in the Free State and Western Cape Provinces of South Africa

BACKGROUND

Studies have shown a mixed association between socioeconomic status (SES) and prevalent HIV infection across and within settings in sub-Saharan Africa. In general, the relationship between years of formal education and HIV infection changed from a positive to a negative association with maturity of the HIV epidemic. Our objective was to determine the association between SES and HIV in women of reproductive age in the Free State (FSP) and Western Cape Provinces (WCP) of South Africa (SA).

STUDY DESIGN

Cross-sectional.

SETTING

SA.

METHODS

We conducted secondary analysis on 1906 women of reproductive age from a 2007 to 2008 survey that evaluated effectiveness of Prevention of Mother-to-Child HIV Transmission Programmes. SES was measured by household wealth quintiles, years of formal education and employment status. Our analysis principally used logistic regression for survey data.

RESULTS

There was a significant negative trend between prevalent HIV infection and wealth quintile in WCP (P<0.001) and FSP (P=0.025). In adjusted analysis, every additional year of formal education was associated with a 10% (adjusted OR (aOR) 0.90 (95% CI 0.85 to 0.96)) significant reduction in risk of prevalent HIV infection in WCP but no significant association was observed in FSP (aOR 0.99; 95% CI 0.89 to 1.11). There was no significant association between employment and prevalent HIV in each province: (aOR 1.54; 95% CI 0.84 to 2.84) in WCP and (aOR 0.96; 95% CI 0.71 to 1.30) in FSP.

CONCLUSION

The association between HIV infection and SES differed by province and by measure of SES and underscores the disproportionately higher burden of prevalent HIV infection among poorer and lowly educated women. Our findings suggest the need for re-evaluation of whether current HIV prevention efforts meet needs of the least educated (in WCP) and the poorest women (both WCP and FSP), and point to the need to investigate additional or tailored strategies for these women.

The global coverage of prevalence data for mental disorders in children and adolescents

AIMS

Children and adolescents make up almost a quarter of the world's population with 85% living in low- and middle-income countries (LMICs). Globally, mental (and substance use) disorders are the leading cause of disability in young people; however, the representativeness or 'coverage' of the prevalence data is unknown. Coverage refers to the proportion of the target population (ages 5-17 years) represented by the available data.

METHODS

Prevalence data for conduct disorder (CD), attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), eating disorders (EDs), depression, and anxiety disorders were sourced from systematic reviews conducted for the Global Burden of Disease Study 2010 (GBD 2010) and 2013 (GBD 2013). For each study, the location proportion was multiplied by the age proportion to give study coverage. Location proportion was calculated by dividing the total study location population by the total study location population. Age proportion was calculated by dividing the population of the country aged within the age range of the study sample by the population of the country aged within the age range of the study sample. If a study only sampled one sex, study coverage was halved. Coverage across studies was then summed for each country to give coverage by country. This method was repeated at the region and global level, and separately for GBD 2013 and GBD 2010.

RESULTS

Mean global coverage of prevalence data for mental disorders in ages 5-17 years was 6.7% (CD: 5.0%, ADHD: 5.5%, ASDs: 16.1%, EDs: 4.4%, depression: 6.2%, anxiety: 3.2%). Of 187 countries, 124 had no data for any disorder. Many LMICs were poorly represented in the available prevalence data, for example, no region in sub-Saharan Africa had more than 2% coverage for any disorder. While coverage increased between GBD 2010 and GBD 2013, this differed greatly between disorders and few new countries provided data.

CONCLUSIONS

The global coverage of prevalence data for mental disorders in children and adolescents is limited. Practical methodology must be developed and epidemiological surveys funded to provide representative prevalence estimates so as to inform appropriate resource allocation and support policies that address mental health needs of children and adolescents.

Re-focusing HIV prevention messages: a qualitative study in rural Uganda

Background

After 30 years, the human immunodeficiency virus (HIV) remains an epidemic of global concern. To support the increasing emphasis on biomedical interventions for prevention requires a renewed and reframed focus on HIV prevention messages to motivate engagement in risk-reduction activities. This paper examines youth and adult perceptions of HIV prevention messages and HIV risk assessment in a generalized HIV epidemic context in Uganda.

Methods

We conducted 24 focus group discussions and 24 in-depth interviews with 15–45 year olds (n = 218) from three communities in the Rakai district of Uganda in 2012.

Results

We found generational differences in the how people viewed HIV, skepticism around introduction of new interventions, continued misconceptions and fears about condoms, and gender differences in content and salience of HIV prevention messages.

Conclusions

Shifts in HIV education are needed to address gaps in HIV messaging to foster engagement in risk reduction strategies and adoption of newer biomedical approaches to HIV prevention.

What Factors are Responsible for Higher Prevalence of HIV Infection among Urban Women than Rural Women in Tanzania?

BACKGROUND

Tanzania is the country hit the hardest by the HIV epidemic in Sub-Saharan Africa. The present study was carried out to examine the factors of HIV infection among women who lived in an urban area in Tanzania.

METHODS

The Tanzania HIV/AIDS and Malaria Indicator Survey (2011-12) data was used. The sample size for urban and rural women who had been tested for HIV and ever had sex was 2227 and 6210 respectively. Bivariate and multivariate logistic regression analyses were used.

RESULTS

The present study found that rural women were significantly less likely to be HIV-infected compared to urban women (OR = 0.612, p<0.00). About 10% urban women were HIV-infected whereas 5.8% women in rural areas were HIV positive. Women who had more than five sex partners were significantly four times more likely to be HIV-infected as compared to women who had one sex partner (OR = 4.49, p<0.00).

CONCLUSION

The results of this study suggest that less-educated women, women belonging to poor or poorer quintile, women spending nights outside and women having more than one sex partner were significantly more likely to have HIV infection among urban women as compared to rural women. There is an urgent need for a short and effective program to control the HIV epidemic in urban areas of Tanzania especially for less-educated urban women.

Identifying the direct risk source to contain epidemics more effectively

We investigate the impact of people's perceptions regarding the risk of an epidemic by analyzing the differences between local and global risk perceptions on affecting the epidemic threshold. Three issues are introduced to explain such differences: the indirect risk source, the heterogeneous global risk, and heterogeneity in individuals' intrinsic susceptibilities. When the direct risk source is completely undetected, the local risk perception tends to have no effect on the epidemic threshold, and the effect of the local risk is nearly equivalent to that of the global risk perception, thereby also suggesting a reason why global risk perception cannot affect the epidemic threshold. However, there is a surprising effect of the global risk perception: When its heterogeneity is sufficiently high, an increased epidemic threshold value sometimes may lead to a greater infected ratio.

Modelling the potential impact and cost of scaling-up male circumcision in resource poor settings: A case of Uganda

This study modelled estimates of the cost and impact of male circumcision (MC) under different scenarios using the Decision Maker's Program Planning Tool on data from Uganda. Results showed that the number of new adult HIV infections could be reduced by 23 000 if MC could be increased from the current 25% to 80% by 2015. The incidence of HIV could be reduced by 0.2 percentage points over the same period. If a scale up programme is to meet a target of 80% by 2015 then the annual number of MCs performed should be over twice as many as those performed in 2011. The discounted net cost per infection averted would be US$559 for the period 2011-2015 and the country would save US$6 841 per infection. A scale up of MC will reduce HIV prevalence and incidence substantially and it would be highly cost effective. The government should mobilise funding to meet high MC targets that would deliver the desired reduction in prevalence and incidence in a short period of time.

Behaviour and communication change in reducing HIV: is Uganda unique?

The clearest example of declines in HIV prevalence and changes in sexual behaviour comes from Uganda. Are there lessons to learn for other countries or is Uganda unique? In this paper, we assess the epidemiological and behavioural data on Uganda comparatively to other African countries and then analyse data from other populations where HIV has declined. In Uganda, HIV prevalence declined from 21% to 9.8% from 1991-1998, there was a reduction in non-regular sexual partners by 65% and greater levels of communication about AIDS and people with AIDS through social networks, unlike the comparison countries. There is evidence of a basic population level response initiated at community level, to avoid risk, reduce risk behaviours and care for people with AIDS. The basic elements-a continuum of communication, behaviour change and care-were integrated at community level. They were also strongly supported by distinctive Ugandan policies from the 1980s. We identify a similar, early behaviour and communication response in other situations where HIV has declined: Thailand, Zambia and the US Gay community. In Thailand, visits to sex workers decreased by 55% and non-regular partners declined from 28% to 15% (1990-1993): as important as the '100% condom use policy'. Similarly, in Zambia and Ethiopia risk behaviour has decreased and analysis of Sexually Transmitted Disease (STD) rates among Gay populations in the USA shows a decline from as early as 1985 in White Gay populations, with later declines in Hispanic and Black Gay populations. These responses preceded and exceeded HIV prevention. However, where they were built on by distinctive HIV policies, HIV prevention has been scaled and led to national level declines in HIV. It is not easy to transfer the lessons of these successes. They require real social and political capital in addition to financial capital. Nevertheless, similar characteristics are present in community responses in Africa, Asia and USA, and even in fragmented signs of HIV declines in other African cities. Only in a few situations has this behaviour and communication process been recognised, mobilised and built on by HIV prevention policy. Where this has occurred, HIV prevention success has been greater than biomedical approaches or methods introduced from outside. It represents a social vaccine for HIV from Africa, and is available now.

Trends in HIV acquisition, risk factors and prevention policies among youth in Uganda, 1999-2011

OBJECTIVE

The objective of this study is to understand how trends in HIV acquisition among youth can be influenced by change in HIV risk factors, social factors and prevention and treatment programmes.

DESIGN

Trends in HIV incidence (per 1000 person-years), by sex and age group, were estimated using data from youth (15-24 years: n = 22,164) in the Rakai Community Cohort Study. Trends in HIV incidence were compared with trends in previously identified HIV risk factors, social factors and programmes.

METHODS

Poisson and linear regression were used to test for statistical significance and decomposition was used to calculate attribution of risk factors to HIV incidence.

RESULTS

Substantial declines between 1999 and 2011 occurred in sexual experience, multiple partners and sexual concurrency among adolescents and young adults. HIV acquisition declined substantially (86%, P = 0.006) among adolescent women (15-19 years) but not among men or young adult women. Changes in HIV incidence and risk behaviours coincided with increases in school enrolment, decline in adolescent marriage, availability of antiretroviral therapy (ART) and increases in male medical circumcision (MMC). Much of the decline in HIV incidence among adolescent women (71%) was attributable to reduced sexual experience; the decline in sexual experience was primarily attributable to increasing levels of school enrolment.

CONCLUSION

Dramatic decreases in HIV incidence occurred among adolescent women in Rakai. Changes in school enrolment and sexual experience were primarily responsible for declining HIV acquisition over time among adolescent women. Given limited improvement among young men and young adult women, the need for effective HIV prevention for young people remains critical.

Correlates of prevalent HIV infection among adults and adolescents in the Kisumu incidence cohort study, Kisumu, Kenya

We estimated HIV prevalence and identified correlates of HIV infection among 1106 men and women aged 16-34 years residing in Kisumu, Kenya. Demographic, sexual, and other behavioural data were collected using audio computer-assisted self-interview in conjunction with a medical examination, real-time parallel rapid HIV testing, and laboratory testing for pregnancy, gonorrhoea, chlamydia, syphilis, and herpes simplex virus type 2. Multivariate logistic regression was used to identify variables associated with prevalent HIV infection by gender. Overall HIV prevalence was 12.1%. HIV prevalence among women (17.1%) was approximately two-and-one-half times the prevalence among men (6.6%). Odds of HIV infection in men increased with age (aOR associated with one-year increase in age = 1.21, CI = 1.07-1.35) and were greater among those who were uncircumcised (aOR = 4.42, CI = 1.41-13.89) and those who had an herpes simplex virus type 2-positive (aOR = 3.13, CI = 1.12-8.73) test result. Odds of prevalent HIV infection among women also increased with age (aOR associated with one-year increase in age = 1.16, CI = 1.04-1.29). Women who tested herpes simplex virus type 2 positive had more than three times the odds (aOR = 3.85, CI = 1.38-10.46) of prevalent HIV infection compared with those who tested herpes simplex virus type 2 negative. Tailored sexual health interventions and programs may help mitigate HIV age and gender disparities.

The Historiography of HIV and AIDS in Uganda

Uganda has been in the world headlines since the mid-1980s, first as a nation severely hit by HIV and AIDS, and later, from the late 1990s onwards, as the first country in sub-Saharan Africa that has managed to reverse a generalised HIV epidemic. Countless newspaper articles, television and radio documentaries and broadcasts, papers, books, and films have been produced about AIDS in Uganda, making the epidemic one of the most thoroughly researched and documented in the world. Medical doctors, virologists, epidemiologists and social and behavioral scientists, both Ugandan and expatriate, have produced massive amounts of scientific information about it since the early 1980s, in addition to which there have been policy papers, evaluation reports, and action plans produced by various government ministries, international donor agencies, and national and international NGOs and relief organizations which document the epidemic from administrative, developmental, and humanitarian perspectives.

Uganda's AIDS epidemic has been publicized worldwide through the news media and various international agencies. It is being constantly monitored not only by national authorities and international health experts, but by myriads of Ugandan and international organizations, media, academics, and concerned members of the public using modern means of communication. Some of these national and international bodies not only monitor, report and educate, but demand their say in how the epidemic should be managed. Uganda has become a testing ground for medical and behavioral interventions, as exemplified by AIDS vaccination trials, the social marketing of condoms, antiretroviral treatment, and, recently, by the male circumcision trial. Positive results have then been marketed to other countries in sub-Saharan Africa as successful AIDS prevention strategies.

Spatial variability in HIV prevalence declines in several countries in sub-Saharan Africa

Evidence suggests substantial declines in HIV prevalence in parts of sub-Saharan Africa. However, the observed aggregate declines at the national level may obscure local variations in the temporal dynamics of the infection. Using spatial scan statistics, we identified marked spatial variability in the within-country declines in HIV prevalence in Tanzania, Malawi, Kenya, and Zimbabwe. Our study suggests that the declines in the national HIV prevalence in some of the SSA countries may not be representative of downward trends in prevalence in areas of high HIV prevalence, as much as the result of sharp declines in prevalence in areas of already low HIV prevalence. Our findings provide insights for resource allocation and HIV prevention interventions in these countries.

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.

Measuring and modelling concurrency

This article explores three critical topics discussed in the recent debate over concurrency (overlapping sexual partnerships): measurement of the prevalence of concurrency, mathematical modelling of concurrency and HIV epidemic dynamics, and measuring the correlation between HIV and concurrency. The focus of the article is the concurrency hypothesis - the proposition that presumed high prevalence of concurrency explains sub-Saharan Africa's exceptionally high HIV prevalence. Recent surveys using improved questionnaire design show reported concurrency ranging from 0.8% to 7.6% in the region. Even after adjusting for plausible levels of reporting errors, appropriately parameterized sexual network models of HIV epidemics do not generate sustainable epidemic trajectories (avoid epidemic extinction) at levels of concurrency found in recent surveys in sub-Saharan Africa. Efforts to support the concurrency hypothesis with a statistical correlation between HIV incidence and concurrency prevalence are not yet successful. Two decades of efforts to find evidence in support of the concurrency hypothesis have failed to build a convincing case.

Condom availability in high risk places and condom use: a study at district level in Kenya, Tanzania and Zambia

Background

A number of studies from countries with severe HIV epidemics have found gaps in condom availability, even in places where there is a substantial potential for HIV transmission. Although reported condom use has increased in many African countries, there are often big differences by socioeconomic background. The aim of this study was to assess equity aspects of condom availability and uptake in three African districts to evaluate whether condom programmes are given sufficient priority.

Methods

Data on condom availability and use was examined in one district in Kenya, one in Tanzania and one in Zambia. The study was based on a triangulation of data collection methods in the three study districts: surveys in venues where people meet new sexual partners, population-based surveys and focus group discussions. The data was collected within an overall study on priority setting in health systems.

Results

At the time of the survey, condoms were observed in less than half of the high risk venues in two of the three districts and in 60% in the third district. Rural respondents in the population-based surveys perceived condoms to be less available and tended to be less likely to report condom use than urban respondents. Although focus group participants reported that condoms were largely available in their district, they expressed concerns related to the accessibility of free condoms.

Conclusion

As late as thirty years into the HIV epidemic there are still important gaps in the availability of condoms in places where people meet new sexual partners in these three African districts. Considering that previous studies have found that improved condom availability and accessibility in high risk places have a potential to increase condom use among people with multiple partners, the present study findings indicate that substantial further efforts should be made to secure that condoms are easily accessible in places where sexual relationships are initiated. Although condom distribution in drinking places has been pinpointed in the HIV/AIDS prevention strategies of all the three countries, its priority relative to other HIV/AIDS measures must be reassessed locally, nationally and regionally. In practical terms very clear supply chains of condoms to both formal and informal drinking places could make condom provision better and more reliable.

Gender, peer and partner influences on adolescent HIV risk in rural South Africa

BACKGROUND AND METHODS

In preparation for a school-based intervention in KwaZulu-Natal, South Africa, a cross-sectional survey of potential HIV risk factors in youth aged 14-17 (n=983) was conducted.

RESULTS

Boys were significantly more likely than girls to report lifetime sexual activity (37.7% v. 13.8%, P<0.01). Among boys and girls, 46.1% reported condom use at last sex. Discussion of condom use with a partner was the strongest predictor of condom use (boys, odds ratio (OR)=7.39; girls, OR=5.58, P<0.0001). Age was independently associated with sexual activity for boys (OR=1.49, P<0.0001) and girls (OR=1.74, P=0.02). For boys, perceptions of male peer behaviour were associated with both ever having participated in sexual activity (OR=1.48, P<0.01) and condom use at last sex (OR=1.79, P<0.01). Girls who equated condom use with having numerous partners were more likely to use them. Among boys, results challenged some expected gender beliefs: support for girls' initiative in relationship formation and refusal of sex were significant predictors of sexual activity. Among girls, higher pregnancy risk perception (OR=1.32, P=0.02) and knowledge (OR=4.85, P=0.055) were associated with sexual activity.

CONCLUSIONS

Creating more gender equitable norms can reduce HIV risk behaviours. HIV prevention interventions should build on existing gender equitable beliefs, and work to promote others, including sexual communication and negotiation skills, and modelling of positive peer norms.

Risk factors for HIV-1 infection in a longitudinal, prospective cohort of adults from the Mbeya Region, Tanzania

BACKGROUND

To control the global HIV epidemic, targeted interventions to reduce the incidence of HIV infections are urgently needed until an effective HIV vaccine is available. This study describes HIV-1 incidence and associated risk factors in a general population cohort of adults from Mbeya region, Tanzania, who participated in a vaccine preparedness study.

METHODS

We conducted a closed prospective cohort study with 6-monthly follow-up from 2002 to 2006 enrolling adults from the general population. HIV-1 incidence and risk factors for HIV-1 acquisition were analyzed using Cox regression.

RESULTS

We observed 2578 seronegative participants for a mean period of 3.06 person years (PY) (7471 PY in total). Overall HIV-1 incidence was 1.35 per 100 PY (95% confidence interval [CI], 1.10-1.64/100 PY). The highest overall HIV-1 incidence was found in females from Itende village (1.55 per 100 PY; 95% CI, 0.99-2.30/100 PY); the highest age-specific incidence was observed in semiurban males aged 30 to 34 years (2.75 per 100 PY; 95% CI, 0.75-7.04). HIV-1 acquisition was independently associated with female gender (hazard ratio [HR], 1.64; 95% CI, 1.05-2.57), younger age at enrollment (age 18-19 versus 35-39 years: HR, 0.29; 95% CI, 0.11-0.75), alcohol consumption (almost daily versus none: HR, 2.01; 95% CI, 1.00-4.07), education level (secondary school versus none: HR, 0.39; 95% CI, 0.17-0.89), and number of lifetime sex partners (more than five versus one: HR, 2.22; 95% CI, 1.13-4.36).

CONCLUSIONS

A high incidence of HIV was observed in this cohort, and incident infection was strongly associated with young age, alcohol consumption, low school education level, and number of sex partners. Targeted interventions are needed to address the elevated risk associated with these factors.

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.

Adolescent problem behavior in Nairobi's informal settlements: applying problem behavior theory in sub-Saharan Africa

Adolescent involvement in problem behaviors can compromise health, development, and successful transition to adulthood. The present study explores the appropriateness of a particular theoretical framework, Problem Behavior Theory, to account for variation in problem behavior among adolescents in informal settlements around a large, rapidly urbanizing city in sub-Saharan Africa. Data were collected from samples of never married adolescents of both sexes, aged 12-19, living in two Nairobi slum settlements (N = 1,722). Measures of the theoretical psychosocial protective and risk factor concepts provided a substantial, multi-variate, and explanatory account of adolescent problem behavior variation and demonstrated that protection can also moderate the impact of exposure to risk. Key protective and risk factors constitute targets for policies and programs to enhance the health and well-being of poor urban adolescents in sub-Saharan Africa.

Evidence for changes in behaviour leading to reductions in HIV prevalence in urban Malawi

BACKGROUND

At the epicentre of the HIV epidemic in Eastern Africa, HIV prevalence has appeared to stabilise in most countries. However, there are indications that the HIV epidemic in Malawi has recently declined.

METHODS

We analysed sexual behaviour survey data from Malawi between 2000 and 2004 and HIV prevalence data from the national antenatal clinic HIV surveillance system between 1994 and 2007 using a mathematical modelling technique that can identify associations between behaviour change and reductions in incidence.

RESULTS

In Malawi between 2000 and 2004 there were significant reductions in the proportion of 15-19 year olds starting sex, the proportion of men having sex with more than one woman in the previous year and significant increases in condom use by men with multiple partners. In the same period, prevalence dropped from 26% to 15% in urban areas among pregnant women and reduced by 40% among women aged 15-24 years. In the same period, prevalence remained at ∼12% in rural areas. Mathematical modelling suggests that the declines in prevalence in urban areas were associated with the behaviour changes and that, if the changes are maintained, this will have cumulatively averted 140,000 (95% interval: 65,000 to 160,000) HIV infections by 2010.

CONCLUSION

Changes in sexual behaviour can avert thousands of new HIV infections in mature generalised hyper-endemic settings. In urban Malawi, the reduction in the number of men with multiple partners is likely to have driven the reduction in incidence. Understanding the causes of this change is a priority so that successful programmes and campaigns can be rapidly expanded to rural areas and other countries in the region.

Monitoring trends in HIV prevalence among young people, aged 15 to 24 years, in Manicaland, Zimbabwe

Background

In June 2001, the United Nations General Assembly Special Session (UNGASS) set a target of reducing HIV prevalence among young women and men, aged 15 to 24 years, by 25% in the worst-affected countries by 2005, and by 25% globally by 2010. We assessed progress toward this target in Manicaland, Zimbabwe, using repeated household-based population serosurvey data. We also validated the representativeness of surveillance data from young pregnant women, aged 15 to 24 years, attending antenatal care (ANC) clinics, which UNAIDS recommends for monitoring population HIV prevalence trends in this age group. Changes in socio-demographic characteristics and reported sexual behaviour are investigated.

Methods

Progress towards the UNGASS target was measured by calculating the proportional change in HIV prevalence among youth and young ANC attendees over three survey periods (round 1: 1998-2000; round 2: 2001-2003; and round 3: 2003-2005). The Z-score test was used to compare differences in trends between the two data sources. Characteristics of participants and trends in sexual risk behaviour were analyzed using Student's and two-tailed Z-score tests.

Results

HIV prevalence among youth in the general population declined by 50.7% (from 12.2% to 6.0%) from round 1 to 3. Intermediary trends showed a large decline from round 1 to 2 of 60.9% (from 12.2% to 4.8%), offset by an increase from round 2 to 3 of 26.0% (from 4.8% to 6.0%). Among young ANC attendees, the proportional decline in prevalence of 43.5% (from 17.9% to 10.1%) was similar to that in the population (test for differences in trend: p value = 0.488) although ANC data significantly underestimated the population prevalence decline from round 1 to 2 (test for difference in trend: p value = 0.003) and underestimated the increase from round 2 to 3 (test for difference in trend: p value = 0.012). Reductions in risk behaviour between rounds 1 and 2 may have been responsible for general population prevalence declines.

Conclusions

In Manicaland, Zimbabwe, the 2005 UNGASS target to reduce HIV prevalence by 25% was achieved. However, most prevention gains occurred before 2003. ANC surveillance trends overall were an adequate indicator of trends in the population, although lags were observed. Behaviour data and socio-demographic characteristics of participants are needed to interpret ANC trends.

Declining HIV prevalence and incidence in perinatal women in Harare, Zimbabwe

BACKGROUND

In several recent papers it has been suggested that HIV prevalence and incidence are declining in Zimbabwe as a result of changing sexual behavior. We provide further support for these suggestions, based on an analysis of more extensive, age-stratified, HIV prevalence data from 1990 to 2009 for perinatal women in Harare, as well as data on incidence and mortality.

METHODOLOGY/PRINCIPAL FINDINGS

Pooled prevalence, incidence and mortality were fitted using a simple susceptible-infected (SI) model of HIV transmission; age-stratified prevalence data were fitted using double-logistic functions. We estimate that incidence peaked at 5.5% per year in 1991 declining to 1% per year in 2010. Prevalence peaked in 1998/9 [35.9% (CI95: 31.3-40.7)] and decreased by 67% to 11.9% (CI95: 10.1-13.8) in 2009. For women <20y, 20-24y, 25-29y, 30-34y and ≥35y, prevalence peaked at 25.4%, 34.2%, 47.1%, 44.0% and 33.5% in 1993, 1996, 1997, 1998 and 1999, respectively, declining thereafter in every age group. Among women <25y, prevalence peaked in 1994 at 28.8% declining thereafter by 69% to 8.9% (CI95: 6.8-11.5) in 2009.

CONCLUSION/SIGNIFICANCE

HIV prevalence declined substantially among perinatal women in Harare after 1998 consequent upon a decline in incidence starting in the early 1990s. Our model suggests that this was primarily a result of changes in behavior which we attribute to a general increase in awareness of the dangers of AIDS and the ever more apparent increases in mortality.

Condoms, HIV and the Roman Catholic Church

For decades, the Roman Catholic Church opposed use of condoms to prevent spread of sexually transmitted infections (STI) because of their contraceptive effect. In 2009, Pope Benedict XVI said that widespread use of condoms could worsen the situation, a position rejected as 'unscientific'. Recently, however the Pontiff stated that because the Church considers acts of prostitution and homosexuality to be gravely immoral and disordered, in such specific cases use of a condom might become an initial step in the direction of a moralization leading to an assumption of responsibility and a new awareness of the meaning of sexuality. In doing so, he reaffirmed his belief that condoms cannot solve the problem of STI spread, stressing the Church's position that modern societies no longer see sexuality as an 'expression of love, but only as a sort of drug that people administer to themselves'. The new Papal position has been widely applauded, but made conservative Catholics unhappy. A dialogue with the Church now seems possible: Does concentrating on condoms hinder the effectiveness of other strategies? What are the respective roles of condoms and other approaches to prevent infection spread? Does a special situation exist in Africa requiring specific and focused interventions?

Factors associated with self-reported HIV testing among men in Uganda

This study examined rates and predictors of self-reported HIV testing and willingness to test among married men aged 15-59 in Uganda. The data are nationally representative and drawn from the 2000-01 Uganda Demographic and Health Survey. The results of multiple regression analyses indicate that knowledge about AIDS, a history of paying for sex, spousal communication about HIV prevention, secondary or higher education, household wealth, and neighbourhood knowledge of a test site are associated with an increased likelihood of HIV testing. The higher the frequency of injection use in the past 3 months and the greater the level of interest in learning how to help one's partner have a safe pregnancy, the higher was the likelihood of willingness to test for HIV. Findings suggest that voluntary counselling and testing programmes need to target older married men aged 30-59 and expand services to the Northern region, where previously untested men indicated significantly higher desires of HIV testing.

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.

Economic risk factors for HIV infection among women in rural Haiti: implications for HIV prevention policies and programs in resource-poor settings

AIMS

The goals of this study were to (1) estimate the prevalence of HIV infection among women accessing services at a women's health center in rural Haiti and (2) to identify economic risk factors for HIV infection in this population.

METHODS

Women who accessed healthcare services at this center between June 1999 and December 2002 were recruited to participate. The analysis was based on data from a case-control study of sexually transmitted diseases (STDs) in rural Haiti. HIV prevalence in the study population was 4%.

RESULTS

In multivariate analyses, partner occupation was associated with HIV infection in women, with mechanic (OR 9.0, 95% CI 1.8-45) and market vendor (OR 4.2, 95% CI 1.6-11) reflecting the strongest partner occupational risk factors. Partner's occupation as a farmer reduced the risk of infection in women by 60% (95% CI 0.14-1.1). Factors indicating low socioeconomic status (SES), such as food insecurity (OR 2.0, 95% CI 0.75-5.6) and using charcoal for cooking (OR 1.7, 95% CI 0.72-3.8) suggested an association with HIV infection.

CONCLUSIONS

Given pervasive gender inequality in Haiti, women's economic security often relies on their partners' income earning activities. Our findings show that although factors reflecting poverty are associated with HIV-positive status, stronger associations are observed for women whose partners indicated a more secure occupation (e.g., mechanic or market vendor). Policies and programs that expand access to education and economic opportunities for women and girls may have long-term implications for HIV prevention in Haiti and other resource-poor settings.

Do behavioural differences help to explain variations in HIV prevalence in adolescents in sub-Saharan Africa?

OBJECTIVE

To compare adolescent risk factors for HIV infection in two countries with high adolescent HIV prevalence and two lower prevalence countries with the aim of identifying risk factors that may help explain differences in adolescent HIV prevalence.

METHODS

Data were available from two nationally representative surveys (South Africa, Zimbabwe), two behavioural intervention trials (Tanzania, Zimbabwe) and one population-based cohort (Uganda). Data on variables known or postulated to be risk factors for HIV infection were compared.

RESULTS

Few risk behaviours were markedly more common in the high HIV prevalence populations. Risk factors more common in high HIV prevalence settings were genital ulcers and discharge, and women were more likely to report older male partners.

DISCUSSION

Age mixing may be an important determinate of HIV prevalence in adolescents. Potential reasons for the general lack of association between other adolescent risk factors and adolescent HIV prevalence include adult HIV prevalence, misreported behaviour, different survey methods and other unmeasured adolescent behaviours. If adult factors dominate adolescent HIV risk, it would help explain the failure of behavioural interventions targeted at adolescents and suggests future interventions should include adults.

Changes in HIV prevalence among differently educated groups in Tanzania between 2003 and 2007

OBJECTIVE

HIV prevalence trends suggest that the epidemic is stable or declining in many sub-Saharan African countries. However, trends might differ between socioeconomic groups. Educational attainment is a common measure of socioeconomic position in HIV datasets from Africa. Several studies have shown higher HIV prevalence among more educated groups, but this may change over time. We describe changes in HIV prevalence by educational attainment in Tanzania from 2003 to 2007.

DESIGN AND METHODS

Analysis of data from two large, nationally representative HIV prevalence surveys conducted among adults aged 15-49 years in Tanzania in 2003-2004 (10 934 participants) and 2007-2008 (15 542 participants). We explored whether changes in HIV prevalence differed between groups with different levels of educational attainment after adjustment for potential confounding factors (sex, age, urban/rural residence and household wealth).

RESULTS

Changes in HIV prevalence differed by educational attainment level (interaction test P value = 0.07). HIV prevalence was stable among those with no education (adjusted odds ratio 2007-2008 vs. 2003-2004 1.03, 95% confidence interval 0.72-1.47), whereas showing a small but borderline significant decline among those with primary education (adjusted odds ratio 0.85, 95% confidence interval 0.69-1.03) and a larger statistically significant decline among those with secondary education (adjusted odds ratio 0.53, 95% confidence interval 0.34-0.84).

DISCUSSION

Prevalent HIV infections are now concentrating among those with the lowest levels of education in Tanzania. Although HIV-related mortality, migration and cohort effects might contribute to this, different HIV incidence by educational level between the surveys provides the most likely explanation. Urgent measures to improve HIV prevention among those with limited education and of low socioeconomic position are necessary in Tanzania.

Characteristics of sexual partnerships, not just of individuals, are associated with condom use and recent HIV infection in rural South Africa

Characteristics of sexual partnerships, as well as those of the individuals involved, might influence the use of condoms and risk of HIV transmission. We set out to identify characteristics of non-spousal sexual partnerships associated with condom use at last sex in the previous year and HIV infection in the previous three years among sexually active young people in rural South Africa. We conducted an analysis of follow-up data (collected in 2004) from a cohort of 14-35-year old men and women recruited to a cluster-randomised trial. Data on 1647 non-spousal sexual partnerships during the previous year were reported in 2004 and analysed alongside new HIV infections over the previous three years among 762 individuals who were HIV-negative in 2001. Structured interviews elicited information on sexual behaviour. HIV serostatus was assessed through oral-fluid ELISA. Condom use at last sex was reported for 615/1647 non-spousal sexual partnerships (37.3%) and was more commonly reported by individuals who were younger, more educated and aware of their HIV status. Condom use was more common in casual partnerships, those where the male partner was younger, where sex was less frequent and where the respondent believed the partner to have other sexual contacts. New HIV infection in the last three years was identified for 87/762 individuals (11.4%) and was more common among females and those out of school. Infection risk was associated with the age of the partners and was less common among individuals reporting less frequent intercourse in the previous year. Characteristics of sexual partnerships, as well as those of individuals, are important determinants of condom use and risk of HIV infection. Male characteristics may be particularly important because of their greater capacity to make decisions about HIV prevention. Established non-spousal sexual partnerships are an increasingly important context for HIV transmission in this setting.

Prevalence and correlates of concurrent sexual partnerships in Zambia

Concurrent partnerships may cause more rapid spread of HIV in a population. We examined how the prevalence of parallel relationships changed among men and women aged 15-49 in Zambia from 1998 to 2003 using data collected during the Sexual Behavior Surveys 1998, 2000, and 2003. Predictors of concurrent partnerships among men were studied by univariate and multivariate regression analyses. Thirteen percent of rural and 8% of urban men reported more than one ongoing relationship in 1998, and these proportions declined to 8% and 6%, respectively in 2003. The proportion of women reporting concurrent relationships was 0-2%. The most important predictors of concurrency were early sexual debut, being married, early marriage and absence from home. The reduction in concurrent sexual partnerships is consistent with reductions in other sexual risk behaviors found in other studies and may have contributed to the recently observed decline in HIV prevalence in Zambia.

Behavioral mechanisms in HIV epidemiology and prevention: past, present, and future roles

In the 1980s, behavioral variations across geographically and socially defined populations were the central focus of AIDS research, and behavior change was seen as the primary means of controlling HIV epidemics. Today, biological mechanisms--especially other sexually transmitted infections, antiretroviral therapy, and male circumcision--predominate in HIV epidemiology and prevention. We describe several reasons for this shift in emphasis. Although the shift is understandable, we argue for a sustained focus on behavioral mechanisms in HIV research in order to realize the theoretical promise of interventions targeting the biological aspects of HIV risk. We also provide evidence to suggest that large reductions in HIV prevalence may be accomplished by small changes in behavior. Moreover, we contend that behavioral mechanisms will find their proper place in HIV epidemiology and prevention only when investigators adopt a conceptual model that treats prevalence as a determinant as well as an outcome of behavior and that explicitly recognizes the dynamic interdependence between behavior and other epidemiological and demographic parameters.

Fourteen years of surveillance of HIV-1 prevalence among pregnant women attending antenatal care clinics in western Uganda

This study monitored long-term temporal trends in HIV-1 prevalence in antenatal clinic attendees living in western Uganda. Semi-annual data collection was done from 1991 to 2004. For each woman the following data were recorded: HIV-1 status, age, educational status, marital status, occupation and parity. The results show that the overall HIV-1 prevalence was 15.3% during the entire time period (urban 21.3%, semi-urban 12.7% and rural 7.1%). Between 1991 and 2004, we observed a gradual decline in the HIV-1 prevalence. The decline was most pronounced in urban women aged 15-19 years old and least pronounced in rural women aged 20-24 years. Women above 25 years of age did not show any decline in HIV-1 prevalence over time. The declining HIV-1 prevalence in the younger age groups (15-24 years) likely represents a declining risk for acquiring HIV infection as we have previously shown in the urban sub-sample of this data set.

Effects of neighbourhood-level educational attainment on HIV prevalence among young women in Zambia

BACKGROUND

Investigations of the association between socio-economic position indicators and HIV in East, Central and Southern Africa have chiefly focused on factors that pertain to individual-level characteristics. This study investigated the effect of neighbourhood educational attainment on HIV prevalence among young women in selected urban and rural areas in Zambia.

METHODS

This study re-analysed data from a cross-sectional population survey conducted in Zambia in 2003. The analyses were restricted to women aged 15-24 years (n = 1295). Stratified random cluster sampling was used to select 10 urban and 10 rural clusters. A measure for neighbourhood-level educational attainment was constructed by aggregating individual-level years-in-school. Multi-level mixed effects regression models were run to examine the neighbourhood-level educational effect on HIV prevalence after adjusting for individual-level underlying variables (education, currently a student, marital status) and selected proximate determinants (ever given birth, sexual activity, lifetime sexual partners).

RESULTS

HIV prevalence among young women aged 15-24 years was 12.5% in the urban and 6.8% in the rural clusters. Neighbourhood educational attainment was found to be a strong determinant of HIV infection in both urban and rural population, i.e. HIV prevalence decreased substantially by increasing level of neighbourhood education. The likelihood of infection in low vs. high educational attainment of neighbourhoods was 3.4 times among rural women and 1.8 times higher among the urban women after adjusting for age and other individual-level underlying variables, including education. However, the association was not significant for urban young women after this adjustment. After adjusting for level of education in the neighbourhood, the effect of the individual-level education differed by residence, i.e. a strong protective effect among urban women whereas tending to be a risk factor among rural women.

CONCLUSION

The findings suggested structural effects on HIV prevalence. Future research should include more detailed mapping of neighbourhood factors of relevance to HIV transmission as part of the effort to better understand the causal mechanisms involved.

The effect of educational attainment and other factors on HIV risk in South African women: results from antenatal surveillance, 2000-2005

OBJECTIVES

To assess the effect of educational attainment and other factors on the risk of HIV in pregnant South African women.

DESIGN

Repeated cross-sectional surveys.

METHODS

Pregnant women attending public antenatal clinics were tested for HIV annually between 2000 and 2005, and provided demographic information. Logistic regression models were applied separately to the data collected in each year, to identify factors associated with HIV infection. Data from all years were combined in a logistic regression model that tested for trends in HIV prevalence.

RESULTS

Amongst women aged 15-24 years, HIV risk in those who had completed secondary education was significantly lower than in those who had only primary education, in all years except 2000. HIV risk increased by 8% per annum (odds ratio 1.08, 95% confidence interval 1.04-1.12) in young women with no secondary education but did not increase in young women with secondary education. In women aged 25-49 years, HIV risk increased over the 2000-2005 period, at all levels of educational attainment, and did not differ between women with completed secondary education and women with only primary education.

CONCLUSION

Together with other evidence, this study suggests that higher educational attainment did not protect against HIV in the early stages of the South African HIV/AIDS epidemic. In recent years, the risk of HIV infection in young South African women with completed secondary education has reduced significantly relative to that in young women with primary education, suggesting that HIV prevention strategies may have been more effective in more educated women.

HIV-prevention science at a crossroads: advances in reducing sexual risk

PURPOSE OF REVIEW

We review the current state of evidence-based prevention strategies for reducing sexual transmission of HIV. The combined programmatic and scientific efforts through 2008 to reduce sexual transmission of HIV have failed to reduce substantially the global pandemic.

RECENT FINDINGS

Prevention interventions to reduce HIV infection target behavioral, biomedical, and structural risk factors. Some of these prevention strategies have been evaluated in randomized clinical trials (RCTs) with HIV seroincidence endpoints. When RCTs are not feasible, a variety of observational and quasiexperimental research approaches can provide insight as to program effectiveness of specific strategies. Only five RCTs have demonstrated a notable decrease in sexually acquired HIV incidence. These include the Mwanza study of syndromic management of sexually transmitted diseases and three male circumcision trials in East Africa; a microbicide trial reported in 2009 shows substantial promise for the efficacy of PRO 2000 (0.5% gel).

SUMMARY

The combined programmatic and scientific efforts to reduce sexual transmission of HIV have made incremental progress. New prevention tools are needed to stem the continued spread of HIV, though microbicides and vaccines will take many more years to develop, test, and deploy. Combination strategies of existing modalities should be tested to evaluate the potential for more proximate prevention benefits.

Assessing evidence for behaviour change affecting the course of HIV epidemics: a new mathematical modelling approach and application to data from Zimbabwe

BACKGROUND

Determining whether interventions to reduce HIV transmission have worked is essential, but complicated by the potential for generalised epidemics to evolve over time without individuals changing risk behaviour. We aimed to develop a method to evaluate evidence for changes in risk behaviour altering the course of an HIV epidemic.

METHODS

We developed a mathematical model of HIV transmission, incorporating the potential for natural changes in the epidemic as it matures and the introduction of antiretroviral treatment, and applied a Bayesian Melding framework, in which the model and observed trends in prevalence can be compared. We applied the model to Zimbabwe, using HIV prevalence estimates from antenatal clinic surveillance and house-hold based surveys, and basing model parameters on data from sexual behaviour surveys.

RESULTS

There was strong evidence for reductions in risk behaviour stemming HIV transmission. We estimate these changes occurred between 1999 and 2004 and averted 660,000 (95% credible interval: 460,000-860,000) infections by 2008.

DISCUSSION

The model and associated analysis framework provide a robust way to evaluate the evidence for changes in risk behaviour affecting the course of HIV epidemics, avoiding confounding by the natural evolution of HIV epidemics.

Relatively low HIV infection rates in rural Uganda, but with high potential for a rise: a cohort study in Kayunga District, Uganda

Background

Few studies have been conducted in Uganda to identify and quantify the determinants of HIV-1 infection. We report results from a community-based cohort study, whose primary objectives were to determine HIV-1 prevalence, incidence, and determinants of these infections, among other objectives.

Methodology

Consenting volunteers from the rural district of Kayunga in Uganda aged 15–49 years were enrolled between March and July 2006. Participants were evaluated every six months. A questionnaire that collected information on behavioral and other HIV-1 risk factors was administered, and a blood sample obtained for laboratory analysis at each study visit.

Principal Findings

HIV-1 prevalence among the 2025 participants was 9.9% (95% CI = 8.6%–11.2%). By the end of 12 months of follow-up, 1689.7 person-years had been accumulated, with a median follow-up time of 11.97 months. Thirteen HIV-1 incident cases were detected giving an annual HIV-1 incidence of 0.77% (95% CI = 0.35–1.19). Prevalence of HSV-2 infection was 57% and was strongly associated with prevalent HIV-1 infection (adjusted Odds Ratio = 3.9, 95% CI = 2.50–6.17); as well as incident HIV-1 infection (adjusted Rate Ratio (RR) = 8.7, 95% CI = 1.11–67.2). The single most important behavioral characteristic associated with incident HIV infection was the number of times in the past 6 months, a participant had sex with person(s) they suspected/knew were having sex with others; attaining statistical significance at 10 times and higher (adjusted RR = 6.3, 95% CI = 1.73–23.1). By the end of 12 months of follow-up, 259 participants (13%) were lost to follow-up, 13 (0.6%) had died, and 2 (0.1%) had withdrawn consent.

Conclusions

Despite relatively low HIV-1 incidence observed in this community, prevalence remains relatively high. In the presence of high prevalence of HSV-2 infection and the behavioral characteristic of having sex with more than one partner, there is potential for increase in HIV-1 incidence.

Heterogeneity in host HIV susceptibility as a potential contributor to recent HIV prevalence declines in Africa

BACKGROUND

HIV prevalence has recently declined in several African countries, and prior to this the risk of HIV acquisition per unprotected sex contact also declined in Kenyan sex workers. We hypothesized that heterogeneity in HIV host susceptibility might underpin both of these observations.

METHODS

A compartmental mathematical model was used to explore the potential impact of heterogeneity in susceptibility to HIV infection on epidemic behavior, in the absence of other causative mechanisms.

RESULTS

Studies indicated that a substantial heterogeneity in susceptibility to HIV infection may lead to an epidemic that peaks and then declines due to a depletion of the most susceptible individuals, even without changes in sexual behavior. This effect was most notable in high-risk groups such as female sex workers and was consistent with empirical data.

DISCUSSION

Declines in HIV prevalence may have other causes in addition to behavior change, including heterogeneity in host HIV susceptibility. There is a need to further study this heterogeneity and its correlates, particularly as it confounds the ability to attribute HIV epidemic shifts to specific interventions, including behavior change.