Risk Factors for HIV Infection in a National Adult Population

Variations in sexual network connectivity may explain dramatic variations in sexually transmitted infection prevalence between populations and over time: a selected four-country analysis

Background: The incidence of sexually transmitted infections (STIs) has been noted to vary dramatically between population groups and over time. Here, the hypothesis that changes in network connectivity underpin these changes is explored.

Methods: The incidence/prevalence estimates of HIV, herpes simplex virus-2, syphilis, chlamydia, and gonorrhoea, as well as two markers of sexual network connectivity (partner concurrency and multiple partnering) by ethnic group and sexual orientation in Kenya, South Africa, the United Kingdom (UK) and the United States (USA) were extracted from published studies. Pearson’s correlation was used to test the association between the markers of network connectivity and the incidence/prevalence of these five STIs. A literature review was performed to evaluate the possible causes of the increases and decreases in syphilis incidence over the past 60 years.

Results: In each country, the five STIs were found to cluster in particular ethnic groups and sexual orientations and to be positively associated with the two markers of network connectivity. Syphilis incidence in the UK and USA was found to increase dramatically in the 1960s/1970s, decline in the 1980s and again increase in the late 1990s. These changes took place predominantly in men who have sex with men, and were preceded by corresponding changes in network connectivity. The large decline in antenatal syphilis prevalence in Kenya and South Africa in the 1990s were likewise preceded by declines in network connectivity.

Conclusions: Although other explanatory variables are not controlled for, the present analysis is compatible with the hypothesis that differential network connectivity is a parsimonious explanation for variations in STI incidence over time and between populations.

Methods for conducting trends analysis: roadmap for comparing outcomes from three national HIV Population-based household surveys in Kenya (2007, 2012, and 2018)

BACKGROUND

For assessing the HIV epidemic in Kenya, a series of independent HIV indicator household-based surveys of similar design can be used to investigate the trends in key indicators relevant to HIV prevention and control and to describe geographic and sociodemographic disparities, assess the impact of interventions, and develop strategies. We developed methods and tools to facilitate a robust analysis of trends across three national household-based surveys conducted in Kenya in 2007, 2012, and 2018.

METHODS

We used data from the 2007 and 2012 Kenya AIDS Indicator surveys (KAIS 2007 and KAIS 2012) and the 2018 Kenya Population-based HIV Impact Assessment (KENPHIA 2018). To assess the design and other variables of interest from each study, variables were recoded to ensure that they had equivalent meanings across the three surveys. After assessing weighting procedures for comparability, we used the KAIS 2012 nonresponse weighting procedure to revise normalized KENPHIA weights. Analyses were restricted to geographic areas covered by all three surveys. The revised analysis files were then merged into a single file for pooled analysis. We assessed distributions of age, sex, household wealth, and urban/rural status to identify unexpected changes between surveys. To demonstrate how a trend analysis can be carried out, we used continuous, binary, and time-to-event variables as examples. Specifically, temporal trends in age at first sex and having received an HIV test in the last 12 months were used to demonstrate the proposed analytical approach. These were assessed with respondent-specific variables (age, sex, level of education, and marital status) and household variables (place of residence and wealth index). All analyses were conducted in SAS 9.4, but analysis files were created in Stata and R format to support additional analyses.

RESULTS

This study demonstrates trends in selected indicators to illustrate the approach that can be used in similar settings. The incidence of early sexual debut decreased from 11.63 (95% CI: 10.95-12.34) per 1,000 person-years at risk in 2007 to 10.45 (95% CI: 9.75-11.2) per 1,000 person-years at risk in 2012 and to 9.58 (95% CI: 9.08-10.1) per 1,000 person-years at risk in 2018. HIV-testing rates increased from 12.6% (95% CI: 11.6%-13.6%) in 2007 to 56.1% (95% CI: 54.6%-57.6%) in 2012 but decreased slightly to 55.6% [95% CI: 54.6%-56.6%) in 2018. The decrease in incidence of early sexual debut could be convincingly demonstrated between 2007 and 2012 but not between 2012 and 2018. Similarly, there was virtually no difference between HIV Testing rates in 2012 and 2018.

CONCLUSIONS

Our approach can be used to support trend comparisons for variables in HIV surveys in low-income settings. Independent national household surveys can be assessed for comparability, adjusted as appropriate, and used to estimate trends in key indicators. Analyzing trends over time can not only provide insights into Kenya's progress toward HIV epidemic control but also identify gaps.

Has the relationship between wealth and HIV risk in Sub-Saharan Africa changed over time? A temporal, gendered and hierarchical analysis

This study examines the relationship between wealth and HIV infection in Sub-Saharan Africa to determine whether and how this relationship has varied over time, within and across countries, by gender, and urban environment. The analysis draws on DHS and AIS data from 27 Sub-Saharan African countries, which spanned the 14 years between 2003 and 2016. We first use logistic regression analyses to assess the relationship between individual wealth, HIV infection and gender by country and year stratified on urban environment. We then use meta-regression analyses to assess the relationship between country level measures of wealth and the odds of HIV infection by gender and individual level wealth, stratified on urban environment. We find that there is a persistent and positive relationship between wealth and the odds of HIV infection across countries, but that the strength of this association has weakened over time. The rate of attenuation does not appear to differ between urban/rural strata. Likewise, we also find that these associations were most pronounced for women and that this relationship was persistent over the study period and across urban and rural strata. Overall, our findings suggest that the relationship between wealth and HIV infection is beginning to reverse and that in the coming years, the relationship between wealth and HIV infection in Sub-Saharan Africa may more clearly mirror the predominant global picture.

Sociodemographic Predictors of HIV Infection among Pregnant Women in Botswana: Cross-Sectional Study at 7 Health Facilities

Objectives:

To determine the prevalence and sociodemographic predictors of HIV among pregnant women in Botswana.

Methods:

This was a cross-sectional study of randomly enrolled women aged 18 to 49 years, attending 7 health facilities in Botswana. Data were gathered from November 2017 to March 2018 and analyzed using SPSS version 24.

Result:

Of the 429 women enrolled, 407 (96.4%) were included in the analysis. The HIV prevalence was 17%; 69 of 407 (95% CI: 13.4- 21.0). Women aged 35 to 49 years had higher HIV prevalence than those 18 to 24 years (adjusted odds ratio [AOR] = 6.2; 95% CI: 2.7-14.4). Illiterate and elementary school educated women had higher HIV prevalence than those with a tertiary education (AOR = 8.5; 95% CI: 1.8-39.1). Those with a history of alcohol intake had a higher HIV prevalence than those without (AOR = 2.6; 95% CI: 1.3-5.3).

Conclusion:

HIV prevalence was lower than it was in 2011. Age, level of education, and history of alcohol intake were strong predictors for HIV infection calling for targeted behavioral change interventions.

Socio-behavioural characteristics and HIV: findings from a graphical modelling analysis of 29 sub-Saharan African countries

INTRODUCTION

Socio-behavioural factors may contribute to the wide variance in HIV prevalence between and within sub-Saharan African (SSA) countries. We studied the associations between socio-behavioural variables potentially related to the risk of acquiring HIV.

METHODS

We used Bayesian network models to study associations between socio-behavioural variables that may be related to HIV. A Bayesian network consists of nodes representing variables, and edges representing the conditional dependencies between variables. We analysed data from Demographic and Health Surveys conducted in 29 SSA countries between 2010 and 2016. We predefined and dichotomized 12 variables, including factors related to age, literacy, HIV knowledge, HIV testing, domestic violence, sexual activity and women's empowerment. We analysed data on men and women for each country separately and then summarized the results across the countries. We conducted a second analysis including also the individual HIV status in a subset of 23 countries where this information was available. We presented summary graphs showing associations that were present in at least six countries (five in the analysis with HIV status).

RESULTS

We analysed data from 190,273 men (range across countries 2295 to 17,359) and 420,198 women (6621 to 38,948). The two variables with the highest total number of edges in the summary graphs were literacy and rural/urban location. Literacy was negatively associated with false beliefs about AIDS and, for women, early sexual initiation, in most countries. Literacy was also positively associated with ever being tested for HIV and the belief that women have the right to ask their husband to use condoms if he has a sexually transmitted infection. Rural location was positively associated with false beliefs about HIV and the belief that beating one's wife is justified, and negatively associated with having been tested for HIV. In the analysis including HIV status, being HIV positive was associated with female-headed household, older age and rural location among women, and with no variables among men.

CONCLUSIONS

Literacy and urbanity were strongly associated with several factors that are important for HIV acquisition. Since literacy is one of the few variables that can be improved by interventions, this makes it a promising intervention target.

Social determinants of pulmonary tuberculosis in Brazil: an ecological study

Background

Social determinants may influence the incidence and control of tuberculosis (TB). The aim of this study was to evaluate the correlation between social determinants and pulmonary TB (PTB) incidence and treatment outcomes in different regions in Brazil.

Methods

In this ecological study, PTB incidence and treatment outcome rates as well as HIV incidence for all 5560 Brazilian cities as reported to the Brazilian Tuberculosis Program in 2010 were correlated with two social indicators, the Human Development Index (HDI) and Gini Index (GI). Cities were stratified into six groups based on location (metropolitan region or not) and size (small, medium, and large cities), and according to the regions of the country to which they belong. The Spearman correlation coefficient was used to assess the association between variables.

Results

In 2010, 68,729 new PTB cases were reported in Brazil, with an incidence rate of 36 cases per 100,000 inhabitants. Incidence rates and PTB mortality demonstrated a weak negative correlation with HDI and a positive correlation with GI. The correlation between HDI and GI with cure, relapse, and lost to follow-up of treatment greatly varied in the different groups of cities and regions of the country evaluated.

Conclusions

There is a weak correlation between HDI and GI and PTB incidence and mortality rate. However, there is great variation between the HDI and GI and cure, relapse, and lost to follow-up in the different groups of cities and regions of the country. This suggests that for TB determination, these outcome variables might be more related to the quality of healthcare provided by services than to social determinants in the general population.

Strong association between higher-risk sex and HIV prevalence at the regional level: an ecological study of 27 sub-Saharan African countries

Background: It is unclear why HIV prevalence varies by nearly two orders of magnitude between regions within countries in sub-Saharan Africa. In this ecological study, we assess if HIV prevalence by region is associated with any of four markers of higher risk sexual behavior: lifetime number of partners, multiple partners in past year, higher risk sex (defined as sex with non-cohabiting, non-marital partners) and age at debut. Methods: We performed Pearson's correlation between the 4 behavioral risk factors and HIV prevalence by region in 47 nationally representative surveys from 27 sub-Saharan African countries, separately by gender. In addition, principal components analysis was used to reduce the eight risk factors (four for each gender) to two principal components (PCs). Mixed effects linear regression was used to assess the relationship between the resulting two PCs and HIV prevalence after controlling for the prevalence of male circumcision. Results: HIV prevalence varied by a median 3.7 fold (IQR 2.9-7.9) between regions within countries. HIV prevalence was strongly associated with higher risk sex and, to a lesser extent, the other risk factors evaluated. Both PCs were strongly associated with HIV prevalence when assessed via linear regression. Conclusions: Differences in sexual behavior may underpin the large differences in HIV-prevalence between subpopulation within sub-Saharan African countries.

Implicit attitudes to sexual partner concurrency vary by sexual orientation but not by gender-A cross sectional study of Belgian students

High rates of sexual partner concurrency have been shown to facilitate the spread of various sexually transmitted infections. Assessments of explicit attitudes to concurrency have however found little difference between populations. Implicit attitudes to concurrency may vary between populations and play a role in generating differences in the prevalence of concurrency. We developed a concurrency implicit associations test (C-IAT) to assess if implicit attitudes towards concurrency may vary between individuals and populations and what the correlates of these variations are. A sample of 869 Belgian students (mean age 23, SD 5.1) completed an online version of the C-IAT together with a questionnaire concerning sexual behavior and explicit attitudes to concurrency. The study participants C-IATs demonstrated a strong preference for monogamy (-0.78, SD = 0.41). 93.2% of participants had a pro-monogamy C-IAT. There was no difference in this implicit preference for monogamy between heterosexual men and women. Men who have sex with men and women who have sex with women were more likely to exhibit implicit but not explicit preferences for concurrency compared to heterosexual men and women. Correlates of the C-IAT varied between men and women.

Risk factors for HIV positivity among more than 3,400 Tanzanian women

In a cross-sectional study of 3,424 women from urban (Dar es Salaam) and rural (Pwani, Mwanza, and Mtwara) Tanzania, conducted in 2008-2009, we investigated risk factors for human immunodeficiency virus (HIV) and the association between different measures of human papillomavirus (HPV) and HIV positivity. Study participants were interviewed about socio-demographic and reproductive factors and sexual behavior. Blood samples were tested for HIV, and the women underwent a gynecological examination. HPV status was determined by Hybrid Capture 2, and HPV genotyping was performed using the LiPA Extra test. Multivariable logistic regression models estimating odds ratios (OR) and 95% confidence intervals (CI) were used. The overall HIV prevalence was 10.2%. HIV-positive women were more likely to have high-risk (HR) HPV detected (OR = 4.11; 95% CI: 3.23-5.24) and clinically visible genital warts (OR = 4.37; 95% CI: 1.81-10.5). Other risk factors included age, place of residence, education, number of births, lifetime number of sexual partners, and time in present relationship. HIV risk factors among urban and rural women and among HPV-positive and HPV-negative women were similar. HPV vaccination may provide some protection against HIV infection in Tanzania, but focus must still be on preventing established risk factors for HIV.

Spatial modeling of HIV and HSV-2 among women in Kenya with spatially varying coefficients

Background

Disease mapping has become popular in the field of statistics as a method to explain the spatial distribution of disease outcomes and as a tool to help design targeted intervention strategies.

Most of these models however have been implemented with assumptions that may be limiting or altogether lead to less meaningful results and hence interpretations. Some of these assumptions include the linearity, stationarity and normality assumptions. Studies have shown that the linearity assumption is not necessarily true for all covariates. Age for example has been found to have a non-linear relationship with HIV and HSV-2 prevalence. Other studies have made stationarity assumption in that one stimulus e.g. education, provokes the same response in all the regions under study and this is also quite restrictive. Responses to stimuli may vary from region to region due to aspects like culture, preferences and attitudes.

Methods

We perform a spatial modeling of HIV and HSV-2 among women in Kenya, while relaxing these assumptions i.e. the linearity assumption by allowing the covariate age to have a non-linear effect on HIV and HSV-2 prevalence using the random walk model of order 2 and the stationarity assumption by allowing the rest of the covariates to vary spatially using the conditional autoregressive model. The women data used in this study were derived from the 2007 Kenya AIDS indicator survey where women aged 15–49 years were surveyed. A full Bayesian approach was used and the models were implemented in R-INLA software.

Results

Age was found to have a non-linear relationship with both HIV and HSV-2 prevalence, and the spatially varying coefficient model provided a significantly better fit for HSV-2. Age-at first sex also had a greater effect on HSV-2 prevalence in the Coastal and some parts of North Eastern regions suggesting either early marriages or child prostitution. The effect of education on HIV prevalence among women was more in the North Eastern, Coastal, Southern and parts of Central region.

Conclusions

The models introduced in this study enable relaxation of two limiting assumptions in disease mapping. The effects of the covariates on HIV and HSV-2 were found to vary spatially. The effect of education on HSV-2 status for example was lower in North Eastern and parts of the Rift region than most of the other parts of the country. Age was found to have a non-linear effect on HIV and HSV-2 prevalence, a linearity assumption would have led to wrong results and hence interpretations. The findings are relevant in that they can be used in informing tailor made strategies for tackling HIV and HSV-2 in different counties. The methodology used here may also be replicated in other studies with similar data.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-016-3022-0) contains supplementary material, which is available to authorized users.

Partner concurrency and HIV infection risk in South Africa

BACKGROUND

The relationship between concurrent sexual partnerships and HIV risk is not fully understood. Evidence on the relationship between partner concurrency (one's sexual partner has another partner) and individual HIV risk is limited. In this study, the relationship between reported sexual partner concurrency and the risk of HIV infection was explored among South Africans.

METHODS

Data from the third South African national HIV survey were used. In this survey, performed in 2008, questionnaires and HIV tests were administered to a nationally representative sample of 15031 persons. Bivariate analysis and multiple logistic regression were used to evaluate the relationship between partner concurrency and HIV serostatus. Spearman's correlation was used to test the association between the prevalence of HIV and partner concurrency by race in women.

RESULTS

The relationship between HIV prevalence and partner concurrency varied by race. At a cross-racial level there was a positive association between HIV prevalence and partner concurrency for women (rho=0.95, p=0.05). Among coloured, white, and Indian persons, HIV prevalence and partner concurrency rates were too low to allow further statistical testing. In the bivariate analysis, black African women who reported partner concurrency had a higher prevalence of HIV (36% (95% confidence interval (CI) 29.7-42.0) vs. 23% (95% CI 19.6-26.1), p<0.001). After controlling for demographic, social, biological, and behavioural variables, the association remained statistically significant (adjusted odds ratio (aOR) 1.4, p=0.04). The association was stronger among 15-29-year-old black African women (aOR 1.8, p=0.03) than among women aged 30 years and older (aOR 1.3, p=0.36).

CONCLUSIONS

These results suggest that partner concurrency may increase the HIV infection risk for black South African women, and in particular, for younger women.

The effects of household wealth on HIV prevalence in Manicaland, Zimbabwe - a prospective household census and population-based open cohort study

Introduction

Intensified poverty arising from economic decline and crisis may have contributed to reductions in HIV prevalence in Zimbabwe.

Objectives

To assess the impact of the economic decline on household wealth and prevalent HIV infection using data from a population-based open cohort.

Methods

Household wealth was estimated using data from a prospective household census in Manicaland Province (1998 to 2011). Temporal trends in summed asset ownership indices for sellable, non-sellable and all assets combined were compared for households in four socio-economic strata (small towns, agricultural estates, roadside settlements and subsistence farming areas). Multivariate logistic random-effects models were used to measure differences in individual-level associations between prevalent HIV infection and place of residence, absolute wealth group and occupation.

Results

Household mean asset scores remained similar at around 0.37 (on a scale of 0 to 1) up to 2007 but decreased to below 0.35 thereafter. Sellable assets fell substantially from 2004 while non-sellable assets continued increasing until 2008. Small-town households had the highest wealth scores but the gap to other locations decreased over time, especially for sellable assets. Concurrently, adult HIV prevalence fell from 22.3 to 14.3%. HIV prevalence was highest in better-off locations (small towns) but differed little by household wealth or occupation. Initially, HIV prevalence was elevated in women from poorer households and lower in men in professional occupations. However, most recently (2009 to 2011), men and women in the poorest households had lower HIV prevalence and men in professional occupations had similar prevalence to unemployed men.

Conclusions

The economic crisis drove more households into extreme poverty. However, HIV prevalence fell in all socio-economic locations and sub-groups, and there was limited evidence that increased poverty contributed to HIV prevalence decline.

Semi-parametric spatial joint modeling of HIV and HSV-2 among women in Kenya

Several diseases have common risk factors. The joint modeling of disease outcomes within a spatial statistical context may provide more insight on the interaction of diseases both at individual and at regional level. Spatial joint modeling allows for studying of the relationship between diseases and also between regions under study. One major approach for joint spatial modeling is the multivariate conditional autoregressive approach. In this approach, it is assumed that all the covariates in the study have linear effects on the multiple response variables. In this study, we relax this linearity assumption and allow some covariates to have nonlinear effects using the penalized regression splines. This model was used to jointly model the spatial variation of human immunodeficiency virus (HIV) and herpes simplex virus-type 2 (HSV-2) among women in Kenya. The model was applied to HIV and HSV-2 prevalence data among women aged 15-49 years in Kenya, derived from the 2007 Kenya AIDS indicator survey. A full Bayesian approach was used and the models were implemented in WinBUGS software. Both diseases showed significant spatial variation with highest disease burdens occurring around the Lake Victoria region. There was a nonlinear association between age of an individual and HIV and HSV-2 infection. The peak age for HIV was around 30 years while that of HSV-2 was about 40 years. A positive significant spatial correlation between HIV and HSV-2 was observed with a correlation of 0.6831(95% CI: 0.3859, 0.871).

Do the factors associated with female HIV infection vary by socioeconomic status in Cameroon?

One of the most consistent findings in social epidemiology is an inverse relationship between indicators of SES and most types of illness. However, a growing body of research on HIV in sub-Saharan Africa suggests an intriguing reversal of this pattern, particularly with respect to HIV among women. In Cameroon, specifically, high-SES women have higher rates of HIV infection compared with low-SES women. Using data from the 2004 Cameroon DHS, this study explored the relationships between SES and HIV and tested a multivariate model designed to highlight the distinctive factors associated with increased risk of HIV among women in different SES classes. The results revealed that high-SES women who reported engaging in riskier sexual behaviour had the highest levels of HIV infection. Surprisingly, among this group increased knowledge of HIV, more domestic decision-making authority and access to health care did not reduce vulnerability. Meanwhile, among low-SES women relative gender inequality was significantly related to HIV risk. Specifically, among this group of women, having a partner with higher education was strongly associated with greater HIV risk. The results suggest that different approaches targeting each sub-group are needed to effectively combat the disease.

Why do some South African ethnic groups have very high HIV rates and others not?

The differences in HIV prevalence between South Africa's racial/ethnic groups (19.9%, 3.2%, and 0.5% among 15-49-year-old blacks, coloureds and whites, respectively) are as big as those between the countries with the highest and lowest levels of HIV prevalence worldwide. These large racial/ethnic differences are largely determined by different sexual network structures. In networks among black South Africans, sexual partnerships are more likely to be arranged concurrently - a configuration that leads to exponential increases in the spread of HIV. An examination of the historical origins of polygamy (where it is normative for partnerships to be arranged concurrently) and monogamy (serial or lifetime) reveals that it is the practice of universal monogamy in stratified societies which is the outlier. The ideology and practice of universal monogamy originated in Europe as the result of several factors, most prominently conflicts between the Christian Church and the nobility. After its imposition in Europe, the European colonial project would see this ideology disseminated around the world. Under the influence of liberalism it would mutate into a secular and unacknowledged value-programme of monogamy as a universal norm. This value-programme and practice of monogamy (mostly serial) is still the norm for white South Africans; thus, this sexual behaviour 'spandrel' (by-product of other historical processes) is a large contributor to the lower levels of HIV prevalence among whites. In pre-colonial African societies, polygyny was normative, and the Christian value-programme of monogamy never achieved the hegemonic status it did in Europe and other areas of conquest. Married black African men who converted to Christianity were no less likely to have additional sexual partners, but only more likely to conceal them. The ongoing secrecy about having concurrent partners has contributed to the connectedness of sexual networks among black Africans at large and in this manner has contributed to the rapid spread of HIV.

Bayesian mapping of HIV infection among women of reproductive age in Rwanda

HIV prevalence is rising and has been consistently higher among women in Rwanda whereas a decreasing national HIV prevalence rate in the adult population has stabilised since 2005. Factors explaining the increased vulnerability of women to HIV infection are not currently well understood. A statistical mapping at smaller geographic units and the identification of key HIV risk factors are crucial for pragmatic and more efficient interventions. The data used in this study were extracted from the 2010 Rwanda Demographic and Health Survey data for 6952 women. A full Bayesian geo-additive logistic regression model was fitted to data in order to assess the effect of key risk factors and map district-level spatial effects on the risk of HIV infection. The results showed that women who had STIs, concurrent sexual partners in the 12 months prior to the survey, a sex debut at earlier age than 19 years, were living in a woman-headed or high-economic status household were significantly associated with a higher risk of HIV infection. There was a protective effect of high HIV knowledge and perception. Women occupied in agriculture, and those residing in rural areas were also associated with lower risk of being infected. This study provides district-level maps of the variation of HIV infection among women of child-bearing age in Rwanda. The maps highlight areas where women are at a higher risk of infection; the aspect that proximate and distal factors alone could not uncover. There are distinctive geographic patterns, although statistically insignificant, of the risk of HIV infection suggesting potential effectiveness of district specific interventions. The results also suggest that changes in sexual behaviour can yield significant results in controlling HIV infection in Rwanda.

Poverty, food insufficiency and HIV infection and sexual behaviour among young rural Zimbabwean women

Background

Despite a recent decline, Zimbabwe still has the fifth highest adult HIV prevalence in the world at 14.7%; 56% of the population are currently living in extreme poverty.

Design

Cross-sectional population-based survey of 18–22 year olds, conducted in 30 communities in south-eastern Zimbabwe in 2007.

Objective

To examine whether the risk of HIV infection among young rural Zimbabwean women is associated with socio-economic position and whether different socio-economic domains, including food sufficiency, might be associated with HIV risk in different ways.

Methods

Eligible participants completed a structured questionnaire and provided a finger-prick blood sample tested for antibodies to HIV and HSV-2. The relationship between poverty and HIV was explored for three socio-economic domains: ability to afford essential items; asset wealth; food sufficiency. Analyses were performed to examine whether these domains were associated with HIV infection or risk factors for infection among young women, and to explore which factors might mediate the relationship between poverty and HIV.

Results

2593 eligible females participated in the survey and were included in the analyses. Overall HIV prevalence among these young females was 7.7% (95% CI: 6.7–8.7); HSV-2 prevalence was 11.2% (95% CI: 9.9–12.4). Lower socio-economic position was associated with lower educational attainment, earlier marriage, increased risk of depression and anxiety disorders and increased reporting of higher risk sexual behaviours such as earlier sexual debut, more and older sexual partners and transactional sex. Young women reporting insufficient food were at increased risk of HIV infection and HSV-2.

Conclusions

This study provides evidence from Zimbabwe that among young poor women, economic need and food insufficiency are associated with the adoption of unsafe behaviours. Targeted structural interventions that aim to tackle social and economic constraints including insufficient food should be developed and evaluated alongside behaviour and biomedical interventions, as a component of HIV prevention programming and policy.

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 Prevalence of HIV by Ethnic Group Is Correlated with HSV-2 and Syphilis Prevalence in Kenya, South Africa, the United Kingdom, and the United States

Background. This paper investigates two issues: do ethnic/racial groups with high HIV prevalences also have higher prevalences of other STIs? and is HIV prevalence by ethnic group correlated with the prevalence of circumcision, concurrency, or having more than one partner in the preceding year? Methods. We used Spearman's correlation to estimate the association between the prevalence of HIV per ethnic/racial group and HSV-2, syphilis, symptoms of an STI, having more than one partner in the past year, concurrency, and circumcision in Kenya, South Africa, the United Kingdom, and the United States. Results. We found that in each country HSV-2, syphilis, and symptomatic STIs were positively correlated with HIV prevalence (HSV-2: Kenya rho = 0.50, P = 0.207; South Africa rho-1, P = 0.000; USA rho-1, P = 0.000, Syphilis: Kenya rho = 0.33, P = 0.420; South Africa rho-1, P = 0.000; USA rho-1, P = 0.000, and STI symptoms: Kenya rho = 0.92, P = 0.001; South Africa rho-1, P = 0.000; UK rho = 0.87, P = 0.058; USA rho-1, P = 0.000). The prevalence of circumcision was only negatively associated with HIV prevalence in Kenya. Both having more than one partner in the previous year and concurrency were positively associated with HIV prevalence in all countries (concurrency: Kenya rho = 0.79, P = 0.036; South Africa rho-1, P = 0.000; UK 0.87, P = 0.058; USA rho-1, P = 0.000 and multiple partners: Kenya rho = 0.82, P = 0.023; South Africa rho-1, P = 0.000; UK rho = 0.87, P = 0.058; USA rho-1, P = 0.000). Not all associations were statistically significant. Conclusion. Further attention needs to be directed to what determines higher rates of partner change and concurrency in communities with high STI prevalence.

Male circumcision and sexual risk behaviors may contribute to considerable ethnic disparities in HIV prevalence in Kenya: an ecological analysis

BACKGROUND

HIV prevalence varies between 0.8 and 20.2% in Kenya's various ethnic groups. The reasons underlying these variations have not been evaluated before.

METHODS

We used data from seven national surveys spanning the period 1989 to 2008 to compare the prevalence of a range of risk factors in Kenya's ethnic groups. Spearman's and linear regression were used to assess the relationship between HIV prevalence and each variable by ethnic group.

RESULTS

The ethnic groups exhibited significant differences in a number of HIV related risk factors. Although the highest HIV prevalence group (the Luo) had the highest rates of HIV testing (Men 2008 survey: 56.8%, 95% CI 51.0-62.5%) and condom usage at last sex (Men 2008∶28.6%, 95% CI 19.6-37.6%), they had the lowest prevalence of circumcision (20.9%, 95% CI 15.9-26.0) the highest prevalence of sex with a non-married, non-cohabiting partner (Men: 40.2%, 95% CI 33.2-47.1%) and pre-marital sex (Men 2008∶73.9%, 95% CI 67.5-80.3%) and the youngest mean age of debut for women (1989 SURVEY: 15.7 years old, 95% CI 15.2-16.2). At a provincial level there was an association between the prevalence of HIV and male concurrency (Spearman's rho = 0.79, P = 0.04). Ethnic groups with higher HIV prevalence were more likely to report condom use (Men 2008 survey: R2 = 0.62, P = 0.01) and having been for HIV testing (Men 2008 survey: R2 = 0.47, P = 0.04).

CONCLUSION

In addition to differences in male circumcision prevalence, variation in sexual behavior may contribute to the large variations in HIV prevalence in Kenya's ethnic groups. To complement the prevention benefits of the medical male circumcision roll-out in several parts of Kenya, interventions to reduce risky sexual behavior should continue to be promoted.

Bayesian spatial semi-parametric modeling of HIV variation in Kenya

Spatial statistics has seen rapid application in many fields, especially epidemiology and public health. Many studies, nonetheless, make limited use of the geographical location information and also usually assume that the covariates, which are related to the response variable, have linear effects. We develop a Bayesian semi-parametric regression model for HIV prevalence data. Model estimation and inference is based on fully Bayesian approach via Markov Chain Monte Carlo (McMC). The model is applied to HIV prevalence data among men in Kenya, derived from the Kenya AIDS indicator survey, with n = 3,662. Past studies have concluded that HIV infection has a nonlinear association with age. In this study a smooth function based on penalized regression splines is used to estimate this nonlinear effect. Other covariates were assumed to have a linear effect. Spatial references to the counties were modeled as both structured and unstructured spatial effects. We observe that circumcision reduces the risk of HIV infection. The results also indicate that men in the urban areas were more likely to be infected by HIV as compared to their rural counterpart. Men with higher education had the lowest risk of HIV infection. A nonlinear relationship between HIV infection and age was established. Risk of HIV infection increases with age up to the age of 40 then declines with increase in age. Men who had STI in the last 12 months were more likely to be infected with HIV. Also men who had ever used a condom were found to have higher likelihood to be infected by HIV. A significant spatial variation of HIV infection in Kenya was also established. The study shows the practicality and flexibility of Bayesian semi-parametric regression model in analyzing epidemiological data.

Why are the benefits of increased resources not impacting the risk of HIV infection for high SES women in Cameroon?

Background

Despite evidence of a positive SES-HIV gradient in some SSA countries, researchers and policy-makers frequently assume that a range of protective interventions – increasing awareness of mechanisms of HIV transmission, techniques for prevention, greater access to health care facilities, and greater availability of condoms – will reduce the likelihood of contracting HIV, even among higher SES populations. We therefore explore the relationships between SES and these intervening behaviors to illuminate the complex factors that link SES and HIV among women in Cameroon.

Methods

We use bivariate and multivariate statistical analysis to examine patterns among the 5, 155 women aged 15–49 who participated in the 2004 CDHS.

Results

The results show a strong pattern where higher SES women have greater access to and use of health care facilities, higher levels of condom use, more HIV knowledge, and command higher power within their relationships, yet also have higher rates of HIV. These traditionally protective factors appear to be offset by riskier sexual behaviors on the part of women with increased resources, most notably longer years of premarital sexual experience, multiple partners in last 12 months, and sexual encounters outside of relationship. Multivariate analyses suggests net of the effect of other factors, women who command higher decision-making power, have greater access to health care, more negative attitudes toward wife beating, longer years of premarital sexual exposure, and partners with professional/white collar jobs (characteristics associated with rising SES) had higher odds of testing positive for HIV.

Conclusion

Results show that higher riskier sexual practices on part of high SES women offset benefits that may have accrued from their increased access to resources. The results suggest that traditional approaches to HIV prevention which rely on poverty reduction, improving access to health care, improving HIV knowledge, and boosting women’s social and economic power may be insufficient to address other drivers of HIV infection among women in SSA.

Multilevel stigma as a barrier to HIV testing in Central Asia: a context quantified

Central Asia is experiencing one of the fastest growing HIV epidemics in the world, with some areas' infection rates doubling yearly since 2000. This study examines the impact of multilevel stigma (individual, family, and community) on uptake of HIV testing and receipt of HIV testing results among women in Central Asia. The sample consists of 38,884 ever-married, Central Asian women between the ages of 15 and 49. Using multilevel modeling (MLM), HIV stigma variables at the individual, family, and community levels were used to assess the significance of differences in HIV testing and receipt of HIV test results among participants while adjusting for possible confounding factors, such as age, wealth, and education. MLM results indicate that HIV stigma is significantly associated with decreased HIV testing uptake at the individual, family, and community levels and with a decrease in receipt at the community level. A one standard deviation increase in individual, family, and community level composite stigma score was associated with a respective 49 %, 59 %, and 94 % (p < 0.001) decrease in the odds of having been tested for HIV. A one standard deviation increase in community composite stigma score was associated with a 99 % (p < 0.001) decrease in the odds of test receipt. HIV stigma operates on the individual, family, and community levels to hinder HIV testing uptake and at the community level to hinder receipt. These findings have important interventions implications to improve uptake of HIV testing and receipt of HIV test results.

HIV, poverty and women

This review examines the interactions of financial status and HIV and its implications for women. MEDLINE and Google scholar were searched using the keywords 'women', 'poverty' and 'HIV' in any field of the article. The search was limited to articles published in English over the last 10 years. The first section of the article tries to establish whether poverty or wealth is a risk factor for HIV. There is credible evidence for both arguments. While wealth shows an increased risk for both sexes, poverty places women at a special disadvantage. The second section explains how the financial status interacts with other 'non biological' factors to put women at increased risk. While discrimination based on these factors disadvantage women, there are some paradoxical observations that do not fit with the traditional line of explanation (e.g. paradoxical impact of wealth and education on HIV). The final section assesses the impact of HIV in driving poverty and the role of women in interventional programmes. The specific impact of poverty on females in families living with HIV is less explored. Though microfinance initiatives to empower women are a good idea in theory, the actual outcome of such a programme is less convincing.

The impact of education and globalization on sexual and reproductive health: retrospective evidence from eastern and southern Africa

The objective of this study is to qualify the relationship between sexual and reproductive health (SRH) and educational attainment in eastern and southern Africa (ESA). We hypothesize that the regional level of globalization is a moderating factor in the relationship between SRH and educational attainment. Using retrospective data from Kenya, Malawi, Tanzania, and Zambia, the associations between SRH (eight indicators), educational attainment, and globalization were examined using multilevel logistic regression analysis. It was found that the model fit for every SRH outcome indicator increased significantly after including the interaction between globalization and educational attainment, supporting the hypothesis. Depending on the level of globalization, three types of relationships between education and SRH were found: (1) for the indicators "more than four children," "intercourse before 17 years," "first child before 20 years," and "one or more child died" education is risk-decreasing, and the reduction is stronger in more globalized regions; (2) for the indicators "condom use at last intercourse" and "current contraceptive use" education is risk-decreasing, and the reduction is stronger in less globalized regions; (3) for the indicators "HIV positive" and "more than four lifetime sexual partners" education is risk increasing, but only in less globalized regions. In conclusion, these effects are related to three types of access: (1) access to services, (2) access to information, and (3) access to sexual networks. The findings highlight the relevance of globalization when analyzing the association between SRH and education, and the importance of structural factors in the development of effective SRH promotion interventions.

Risk factors for HIV-1 infection in India: evidence from the National Family Health Survey

To study demographic, social, behavioural and biological variables as risk factors for HIV infection among men and women in India, we used data from the cross-sectional, population-based National Family Health Survery (NFHS)-3 2005-06. During the survey, 52,853 women aged 15-49 years and 50,093 men aged 15-54 years gave consent to anonymous HIV testing. HIV serostatus data for men and women were analysed for their relationships to key characteristics using bivariate and multivariate techniques. In the analysis of the study sample, in both men and women the ages of highest risk for HIV were between 25 and 34 years. Married, widowed, divorced women and men had higher odds of being HIV-positive; employed individuals also had a higher risk of being HIV-positive (odds ratio [OR] = 1.89 and 2.89, respectively). Muslim women had a lower risk (OR 0.23). Wealth was not found to be associated with HIV serostatus among men in our study sample. In women, a history of genital ulcer or sore significantly increased their risk. Circumcised men were found to be at a lower risk for HIV infection. HIV is a multi-dimensional epidemic, with demographic, residential, social, biological and behavioural factors exerting influence on individual probability of becoming infected with HIV.

Male circumcision

Male circumcision consists of the surgical removal of some, or all, of the foreskin (or prepuce) from the penis. It is one of the most common procedures in the world. In the United States, the procedure is commonly performed during the newborn period. In 2007, the American Academy of Pediatrics (AAP) convened a multidisciplinary workgroup of AAP members and other stakeholders to evaluate the evidence regarding male circumcision and update the AAP's 1999 recommendations in this area. The Task Force included AAP representatives from specialty areas as well as members of the AAP Board of Directors and liaisons representing the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, and the Centers for Disease Control and Prevention. The Task Force members identified selected topics relevant to male circumcision and conducted a critical review of peer-reviewed literature by using the American Heart Association's template for evidence evaluation. Evaluation of current evidence indicates that the health benefits of newborn male circumcision outweigh the risks; furthermore, the benefits of newborn male circumcision justify access to this procedure for families who choose it. Specific benefits from male circumcision were identified for the prevention of urinary tract infections, acquisition of HIV, transmission of some sexually transmitted infections, and penile cancer. Male circumcision does not appear to adversely affect penile sexual function/sensitivity or sexual satisfaction. It is imperative that those providing circumcision are adequately trained and that both sterile techniques and effective pain management are used. Significant acute complications are rare. In general, untrained providers who perform circumcisions have more complications than well-trained providers who perform the procedure, regardless of whether the former are physicians, nurses, or traditional religious providers. Parents are entitled to factually correct, nonbiased information about circumcision and should receive this information from clinicians before conception or early in pregnancy, which is when parents typically make circumcision decisions. Parents should determine what is in the best interest of their child. Physicians who counsel families about this decision should provide assistance by explaining the potential benefits and risks and ensuring that parents understand that circumcision is an elective procedure. The Task Force strongly recommends the creation, revision, and enhancement of educational materials to assist parents of male infants with the care of circumcised and uncircumcised penises. The Task Force also strongly recommends the development of educational materials for providers to enhance practitioners' competency in discussing circumcision's benefits and risks with parents. The Task Force made the following recommendations:Evaluation of current evidence indicates that the health benefits of newborn male circumcision outweigh the risks, and the benefits of newborn male circumcision justify access to this procedure for those families who choose it. Parents are entitled to factually correct, nonbiased information about circumcision that should be provided before conception and early in pregnancy, when parents are most likely to be weighing the option of circumcision of a male child. Physicians counseling families about elective male circumcision should assist parents by explaining, in a nonbiased manner, the potential benefits and risks and by ensuring that they understand the elective nature of the procedure. Parents should weigh the health benefits and risks in light of their own religious, cultural, and personal preferences, as the medical benefits alone may not outweigh these other considerations for individual families. Parents of newborn boys should be instructed in the care of the penis, regardless of whether the newborn has been circumcised or not. Elective circumcision should be performed only if the infant's condition is stable and healthy. Male circumcision should be performed by trained and competent practitioners, by using sterile techniques and effective pain management. Analgesia is safe and effective in reducing the procedural pain associated with newborn circumcision; thus, adequate analgesia should be provided whenever newborn circumcision is performed.Nonpharmacologic techniques (eg, positioning, sucrose pacifiers) alone are insufficient to prevent procedural and postprocedural pain and are not recommended as the sole method of analgesia. They should be used only as analgesic adjuncts to improve infant comfort during circumcision. If used, topical creams may cause a higher incidence of skin irritation in low birth weight infants, compared with infants of normal weight; penile nerve block techniques should therefore be chosen for this group of newborns. Key professional organizations (AAP, the American Academy of Family Physicians, the American College of Obstetricians and Gynecologists, the American Society of Anesthesiologists, the American College of Nurse Midwives, and other midlevel clinicians such as nurse practitioners) should work collaboratively to:Develop standards of trainee proficiency in the performance of anesthetic and procedure techniques, including suturing; Teach the procedure and analgesic techniques during postgraduate training programs; Develop educational materials for clinicians to enhance their own competency in discussing the benefits and risks of circumcision with parents; Offer educational materials to assist parents of male infants with the care of both circumcised and uncircumcised penises. The preventive and public health benefits associated with newborn male circumcision warrant third-party reimbursement of the procedure. The American College of Obstetricians and Gynecologists has endorsed this technical report.

Exploring the connections between HIV serostatus and individual, household, and community socioeconomic resources: evidence from two population-based surveys in Kenya

The positive association between health and socioeconomic status (SES) is well documented. However, available empirical evidence on the SES gradients of HIV serostatus is mixed, and few studies have explored the effects of community SES indicators on individual's HIV risk. Using nationally representative data of women and men from the 2003 Demographic and Health Survey and the 2007 AIDS Indicator Survey from Kenya, we assessed the associations between HIV serostatus and SES as measured by educational attainment and household wealth at the individual/household and community levels. Additionally, we explored changes in these associations between 2003 and 2007. Results from bivariate and cohort analyses showed that during this period, HIV burden shifted from higher to lower SES subgroups at both the individual/household and community levels, particularly among women aged 15-24 years. Results from multi-level logistic regression models showed that this shift was generally significant among women. In addition, communities' collective educational attainment, measured as the percentage of residents with some secondary schooling or higher, was a more significant predictor and protective factor for HIV risk than individual/household-level SES indicators for women in 2007 and men in both years. Our findings highlight the relevance of community-level SES to HIV dynamics in Kenya between 2003 and 2007.

Predictors of Virologic Failure in HIV/AIDS Patients Treated with Highly Active Antiretroviral Therapy in Brasília, Brazil During 2002-2008

Little data exists concerning the efficacy of the antiretroviral therapy in the Federal District in Brazil, therefore in order to improve HIV/AIDS patients’ therapy and to pinpoint hot spots in the treatment, this research work was conducted. Of 139 HIV/AIDS patients submitted to the highly active antiretroviral therapy, 12.2% failed virologically. The significant associated factors related to unresponsiveness to the lentiviral treatment were: patients’ place of origin (OR = 3.28; IC95% = 1.0–9.73; P = 0.032) and Mycobacterium tuberculosis infection (RR = 2.90; IC95% = 1.19–7.02; P = 0.019). In the logistic regression analysis, the remaining variables in the model were: patients’ birthplace (OR = 3.28; IC95% = 1.10–9.73; P = 0.032) and tuberculosis comorbidity (OR = 3.82; IC95% = 1.19–12.22; P = 0.024). The patients enrolled in this survey had an 88.0% therapeutic success rate for the maximum period of one year of treatment, predicting that T CD4⁺ low values and elevated viral loads at pretreatment should be particularly considered in tuberculosis coinfection, besides the availability of new antiretroviral drugs displaying optimal activity both in viral suppression and immunological reconstitution.

No evidence of association between HIV-1 and malaria in populations with low HIV-1 prevalence

BACKGROUND

The geographic overlap between HIV-1 and malaria has generated much interest in their potential interactions. A variety of studies have evidenced a complex HIV-malaria interaction within individuals and populations that may have dramatic effects, but the causes and implications of this co-infection at the population level are still unclear. In a previous publication, we showed that the prevalence of malaria caused by the parasite Plasmodium falciparum is associated with HIV infection in eastern sub-Saharan Africa. To complement our knowledge of the HIV-malaria co-infection, the objective of this work was to assess the relationship between malaria and HIV prevalence in the western region of sub-Saharan Africa.

METHODOLOGY/PRINCIPAL FINDINGS

Population-based cross-sectional data were obtained from the HIV/AIDS Demographic and Health Surveys conducted in Burkina Faso, Ghana, Guinea, Mali, Liberia and Cameroon, and the malaria atlas project. Using generalized linear mixed models, we assessed the relationship between HIV-1 and Plasmodium falciparum parasite rate (PfPR) adjusting for important socio-economic and biological cofactors. We found no evidence that individuals living in areas with stable malaria transmission (PfPR>0.46) have higher odds of being HIV-positive than individuals who live in areas with PfPR≤0.46 in western sub-Saharan Africa (estimated odds ratio 1.14, 95% confidence interval 0.86-1.50). In contrast, the results suggested that PfPR was associated with being infected with HIV in Cameroon (estimated odds ratio 1.56, 95% confidence interval 1.23-2.00).

CONCLUSION/SIGNIFICANCE

Contrary to our previous research on eastern sub-Saharan Africa, this study did not identify an association between PfPR and infection with HIV in western sub-Saharan Africa, which suggests that malaria might not play an important role in the spread of HIV in populations where the HIV prevalence is low. Our work highlights the importance of understanding the epidemiologic effect of co-infection and the relevant factors involved in this relationship for the implementation of effective control strategies.

The better the worse: risk factors for HIV infection among women in Kenya and Uganda: demographic and health survey

The objective of the study was to investigate socio-economic status (SES) factors as risk factors for HIV among women in Kenya and Uganda. Individual data from cross-sectional, population based 2003-Kenya Demographic and Health Survey (KDHS) and 2004-Uganda AIDS Indicator Survey (AIS) were used and the probability of being HIV-positive was analysed. Contrary to the public health literature, women of high SES were also vulnerable to HIV risk. Both Ugandan and Kenyan women had similar SES risk factors to HIV and harmonising policies in the two countries to deal with the disadvantages of the social and cultural roles of women would help reduce vulnerability to HIV for women. Policies in both countries need to be broad based to cut across all socio-economic groups and deal with the complexity of HIV/AIDS. Nyanza region needs exceptional policies to deal with the high HIV prevalence and reduce risk through cultural practices like widow inheritance.

Male circumcision and HIV infection risk

BACKGROUND

Male circumcision is being promoted to reduce human immunodeficiency virus type 1 (HIV) infection rates. This review evaluates the scientific evidence suggesting that male circumcision reduces HIV infection risk in high-risk heterosexual populations.

METHODS

We followed the updated International Consultation on Urological Diseases evidence-based medicine recommendations to critically review the scientific evidence on male circumcision and HIV infection risk.

RESULTS

Level 1 evidence supports the concept that male circumcision substantially reduces the risk of HIV infection. Three major lines of evidence support this conclusion: biological data suggesting that this concept is plausible, data from observational studies supported by high-quality meta-analyses, and three randomized clinical trials supported by high-quality meta-analyses.

CONCLUSIONS

The evidence from these biological studies, observational studies, randomized controlled clinical trials, meta-analyses, and cost-effectiveness studies is conclusive. The challenges to implementation of male circumcision as a public health measure in high-risk populations must now be faced.

A spatial analysis of county-level variation in syphilis and gonorrhea in Guangdong Province, China

Background

Sexually transmitted infections (STI) have made a resurgence in many rapidly developing regions of southern China, but there is little understanding of the social changes that contribute to this spatial distribution of STI. This study examines county-level socio-demographic characteristics associated with syphilis and gonorrhea in Guangdong Province.

Methods/Principal Findings

This study uses linear regression and spatial lag regression to determine county-level (n = 97) socio-demographic characteristics associated with a greater burden of syphilis, gonorrhea, and a combined syphilis/gonorrhea index. Data were obtained from the 2005 China Population Census and published public health data. A range of socio-demographic variables including gross domestic product, the Gender Empowerment Measure, standard of living, education level, migrant population and employment are examined. Reported syphilis and gonorrhea cases are disproportionately clustered in the Pearl River Delta, the central region of Guangdong Province. A higher fraction of employed men among the adult population, higher fraction of divorced men among the adult population, and higher standard of living (based on water availability and people per room) are significantly associated with higher STI cases across all three models. Gross domestic product and gender inequality measures are not significant predictors of reported STI in these models.

Conclusions/Significance

Although many ecological studies of STIs have found poverty to be associated with higher reported STI, this analysis found a greater number of reported syphilis cases in counties with a higher standard of living. Spatially targeted syphilis screening measures in regions with a higher standard of living may facilitate successful control efforts. This analysis also reinforces the importance of changing male sexual behaviors as part of a comprehensive response to syphilis control in China.

Risky behaviour and HIV prevalence among Zambian men

The objective of this paper is to identify demographic, social and behavioural risk factors for HIV infection among men in Zambia. In particular, the role of alcohol, condom use and number of sex partners is highlighted as being significant in the prevalence of HIV. Multivariate logistic regressions were used to analyse the latest cross-sectional population-based demographic health survey for Zambia (2007). The survey included socioeconomic variables and HIV serostatus for consenting men (N = 4434). Risk for HIV was positively related to wealth status. Men who considered themselves to be at high risk of being HIV positive were most likely to be HIV positive. Respondents who, along with their sexual partner, were drunk during the last three times they had sexual intercourse were more likely to be HIV positive (adjusted odds ratio (AOR) 1.60; 95% confidence interval (CI) 1.00-2.56). Men with more than two sexual life partners and inconsistent condom use had a higher risk for being HIV positive (OR 1.89, 95% CI 1.45-2.46; and OR 1.49, 95% CI 1.10-2.02, respectively). HIV prevention programmes in Zambia should focus even more on these behavioural risk factors.

Influence of religious affiliation and education on HIV knowledge and HIV-related sexual behaviors among unmarried youth in rural central Mozambique

The interactions between religious affiliation, education, HIV knowledge, and HIV-related sexual behaviors among African church youth are poorly understood. In this socio-demographic study, 522 unmarried youth 12-28 years old in rural central Mozambique were surveyed with a structured questionnaire. Using binary logistic regression analysis, we used religious affiliation and education to measure influence on (1) HIV transmission and prevention knowledge and attitudes and (2) HIV-related sexual behaviors among youth. Religiously affiliated males were more likely than non-religious males to know when a condom should be used, respond correctly to HIV transmission questions and respond with less stigma to HIV-related scenarios. Increased levels of education among males corresponded significantly to increased knowledge of condom usage and HIV prevention strategies and less likelihood to respond with stigma. Only education levels influenced young female responses. Religious affiliation and education had minimal effects on sexual activity, condom usage, and multiple partnerships. African Independent Church/Zionist males were 1.6 times more likely to be sexually inexperienced than non-religious males but were also significantly less likely to use condoms (0.23, p=0.024). Non-religious youth were most likely to have visited sex workers and did not use condoms. These results suggest that religious affiliation, possibly as the result of educational opportunities afforded by religious-affiliated schools, is contributing to increased HIV transmission and prevention knowledge among youth in rural Central Mozambique but not influencing HIV-related sexual behavior. The need exists to strengthen the capacity of religious congregations to teach about HIV/AIDS and target non-religious youth with HIV transmission and prevention information.

HIV-malaria co-infection: effects of malaria on the prevalence of HIV in East sub-Saharan Africa

OBJECTIVE

To examine the association between malaria and HIV prevalence in East sub-Saharan Africa.

METHODS

Using large nationally representative samples of 19,735 sexually active adults from the 2003-04 HIV/AIDS indicator surveys conducted in Kenya, Malawi and Tanzania, and the atlas malaria project, we analysed the relationship between malaria and HIV prevalence adjusting for important socioeconomic and biological cofactors.

RESULTS

In adjusted models, individuals who live in areas with high Plasmodium falciparum parasite rate (PfPR > 0.42) had increased estimated odds of being HIV positive than individuals who live in areas with low P. falciparum parasite rate (PfPR ≤ 0.10) [men: estimated odds ratio (OR) 2.24, 95% confidence interval (CI) 1.62-3.12; women: estimated OR 2.44, 95% CI 1.85-3.21].

CONCLUSION

This is the first study to report malaria as a risk factor of concurrent HIV infection at the population level. According to our results, individuals who live in areas with high P. falciparum parasite rate have about twice the risk of being HIV positive compared with individuals who live in areas with low P. falciparum parasite rate. Our work emphasizes the need for field studies focused on quantifying the interaction among parasitic infections and risk of HIV infection, and studies to explore the impact of control interventions. Programmes focused on reducing malaria transmission will be important to address, especially in HIV-infected individuals.

Primary syphilis cases in Guangdong Province 1995-2008: opportunities for linking syphilis control and regional development

BACKGROUND

Syphilis cases have risen in many parts of China, with developed regions reporting the greatest share of cases. Since syphilis increases in these areas are likely driven by both increased screening and changes in sexual behaviours, distinguishing between these two factors is important. Examining municipal-level primary syphilis cases with spatial analysis allows a more direct understanding of changing sexual behaviours at a more policy-relevant level.

METHODS

In this study we examined all reported primary syphilis cases from Guangdong Province, a southern province in China, since the disease was first incorporated into the mandatory reporting system in 1995. Spatial autocorrelation statistics were used to correlate municipal-level clustering of reported primary syphilis cases and gross domestic product (GDP).

RESULTS

A total of 52,036 primary syphilis cases were reported over the period 1995-2008, and the primary syphilis cases increased from 0.88 per 100,000 population in 1995 to 7.61 per 100,000 in 2008. The Pearl River Delta region has a disproportionate share (44.7%) of syphilis cases compared to other regions. Syphilis cases were spatially clustered (p = 0.01) and Moran's I analysis found that syphilis cases were clustered in municipalities with higher GDP (p = 0.004).

CONCLUSIONS

Primary syphilis cases continue to increase in Guangdong Province, especially in the Pearl River Delta region. Considering the economic impact of syphilis and its tendency to spatially cluster, expanded syphilis testing in specific municipalities and further investigating the costs and benefits of syphilis screening are critical next steps.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Knowledge of HIV status, sexual risk behaviors and contraceptive need among people living with HIV in Kenya and Malawi

BACKGROUND

Several studies support the need for effective interventions to reduce HIV transmission risk behaviors among people living with HIV/AIDS (PLWHAs).

DESIGN

Cross-sectional nationally representative demographic health survey of Kenya (2003) and Malawi (2004-2005) that included HIV testing for consenting adults.

METHODS

We analyzed demographic health survey data for awareness of HIV status and sexual behaviors of PLWHAs (Kenya: 412; Malawi: 664). The analysis was adjusted (weighted) for the design of the survey and the results are nationally representative.

FINDINGS

Eighty-four percent of PLWHAs in Kenya and 86% in Malawi had sex in the past 12 months and in each country, 10% reported using condoms at last intercourse. Among sexually active PLWHAs, 86% in Kenya and 96% in Malawi reported their spouse or cohabiting partner as their most recent partner. In multivariate logistic regression models, married or cohabiting PLWHAs were significantly more likely to be sexually active and less likely to use condoms. Over 80% of PLWHAs were unaware of their HIV status. Of HIV-infected women, nearly three-quarters did not want more children either within the next 2 years or ever, but 32% in Kenya and 20% in Malawi were using contraception.

INTERPRETATION

In 2003-2005, majority of PLWHAs in Kenya and Malawi were unaware of their HIV status and were sexually active, especially married or cohabiting PLWHAs. Of HIV-infected women not wanting more children, few used contraception. HIV testing should be expanded, prevention programs should target married or cohabiting couples and family planning services should be integrated with HIV services.

Socioeconomic status and HIV seroprevalence in Tanzania: a counterintuitive relationship

OBJECTIVE

To examine the relationship between multiple dimensions of socioeconomic status (SES) and HIV seroprevalence in Tanzania.

METHODS

Using a large nationally representative sample of 7515 sexually active adults drawn from the 2003-04 Tanzania HIV/AIDS Indicator Survey, we analysed the relationship between multiple SES measures and HIV seroprevalence using weighted logistic regression models.

RESULTS

In adjusted models, individuals in the highest quintile of standard of living had increased odds ratio (OR) of being HIV-positive (male: OR 2.38, 95% CI 1.17-4.82; female: OR 3.74, 95% CI 2.16-6.49). Occupational status was differentially associated with HIV in men and women; women in professional jobs had higher OR of being HIV-positive (OR 1.54, 95% CI 1.02-2.38), whereas unemployed men had higher risk of being HIV-positive (OR 3.49, 95% CI 1.43-8.58). No marked association was found between increasing education and HIV seroprevalence for men (P = 0.83) and women (P = 0.87).

CONCLUSION

Contrary to the prevailing perception that low SES individuals tend to be more vulnerable to HIV-infection, we found a positive association between standard of living and HIV-infection. Strategies aimed at reducing HIV-infection needs to be cognizant of the complex social heterogeneity in the patterns of HIV-infection.

Risk compensation in HIV prevention: implications for vaccines, microbicides, and other biomedical HIV prevention technologies

Studies investigating the effects of biologic HIV prevention technologies have been reported with promising results for slowing the spread of the disease. Although they can reduce the rate of HIV transmission at varying levels of efficaciousness, it is vital to anticipate their impact on subsequent sexual behaviors. Risk homeostasis theory posits that decreases in perceived risk, which will occur with access to HIV prevention technologies, will correspond with increases in risk-taking behavior. Here we review the literature on risk compensation in response to HIV vaccines, topical microbicides, antiretroviral medications, and male circumcision. Behavioral risk compensation is evident in response to prevention technologies that are used in advance of HIV exposure and at minimal personal cost. We conclude that behavioral risk compensation should be addressed by implementing adjunct behavioral risk-reduction interventions to avoid negating the preventive benefits of biomedical HIV prevention technologies.

A nested case-control study of sexual practices and risk factors for prevalent HIV-1 infection among young men in Kisumu, Kenya

OBJECTIVES

To investigate sexual practices and risk factors for prevalent HIV infection among young men in Kisumu, Kenya.

GOAL

The goal of this study was to identify behaviors associated with HIV in Kisumu to maximize the effectiveness of future prevention programs.

STUDY DESIGN

Lifetime sexual histories were collected from a nested sample of 1337 uncircumcised participants within the context of a randomized controlled trial of male circumcision to reduce HIV incidence.

RESULTS

Sixty-five men (5%) tested positive for HIV. Multiple logistic regression revealed the following independent predictors of HIV: older age, less education, being married, being Catholic, >4 lifetime sex partners, prior treatment for an STI, sex during partner's menstruation, ever practicing bloodletting, and receipt of a medical injection in the last 6 months. Prior HIV testing and postcoital cleansing were protective.

CONCLUSIONS

This analysis confirms the importance of established risk factors for HIV and identifies practices that warrant further investigation.

LINKING POVERTY AND INCOME SHOCKS TO RISKY SEXUAL BEHAVIOUR: EVIDENCE FROM A PANEL STUDY OF YOUNG ADULTS IN CAPE TOWN

Is there a link between household income and income stress, and risky sexual behaviour of young people? Anecdotal and qualitative evidence suggests this may be the case, but there is little quantitative research measuring this relationship. We use two waves of new data from the Cape Area Panel Study to investigate this link for 2,993 African and coloured youths aged 14 to 22 in 2002. In the process, we discuss one type of research design that could allow for a causal interpretation of the effect of income poverty on HIV risk. This design plausibly separates out the effect of income stress from the effect of living in a poor household by comparing behaviours across households with and without negative economic shocks, conditional on baseline income. Our results indicate that females in poorer households are more likely to be sexually active in 2002 and more likely to sexually debut by 2005. In addition, girls in households experiencing negative economic shocks are more likely to reduce condom use between 2002 and 2005. However, they are less likely to have multiple partners in 2002 or have transitioned to multiple partners by 2005. Males who experienced a negative shock are more likely to have multiple partners. Despite the tight research design for assessing shocks, the findings on the impacts of shocks do not generate clear recommendations for policy. There appears to be no systematic difference in condom use at last sex by household income levels or income shocks.

Household and community income, economic shocks and risky sexual behavior of young adults: evidence from the Cape Area Panel Study 2002 and 2005

OBJECTIVE

To describe recent trends in adolescent sexual behavior in Cape Town, South Africa, and to determine whether household and community poverty and negative economic shocks predict risky sexual behavior.

DATA

Matched survey data on 2993 African and coloured youth from the Cape Area Panel Study 2002 and 2005.

MAIN OUTCOME MEASURES

Sexual debut, multiple sexual partners in past year, condom use at last sex, measured in 2002 and 2005.

METHODS

We tested for changes over time in reported sexual behavior and estimate multivariate probit models to measure the association between 2002 individual, household and community characteristics and 2005 sexual behavior.

RESULTS

There was a statistically significant increase in condom use and a decrease in the incidence of multiple sexual partners between 2002 and 2005 for young women aged 17-22 years. Young women in households with 10% higher income were 0.53% less likely to debut sexually by 2005; young men in communities with a 10% higher poverty rate were 5% less likely to report condom use at last sex. Negative economic shocks are associated with a 0.04% increase in the probability of multiple partnerships for young women. Education is positively correlated with sexual debut for young women and with multiple partnerships for both sexes.

CONCLUSION

Trends in sexual behavior between 2002 and 2005 indicate significant shifts towards safer practices. There is little evidence of a relationship between negative economic shocks, household and community poverty, and risky behavior. We hypothesize that the unexpected positive relationship between education and sexual debut may be driven by peer effects in schools with substantial age mixing.

Is poverty or wealth driving HIV transmission?

Evidence of associations between socioeconomic status and the spread of HIV in different settings and at various stages of the epidemic is still rudimentary. Few existing studies are able to track incidence and to control effectively for potentially confounding factors. This paper reviews the findings of recent studies, including several included in this volume, in an attempt to uncover the degree to which, and the pathways through which, wealth or poverty is driving transmission in sub-Saharan Africa. We investigate the question of whether the epidemic is transitioning from an early phase in which wealth was a primary driver, to one in which poverty is increasingly implicated. The paper concludes by demonstrating the complexity and context-specificity of associations and the critical influence of certain contextual factors such as location, gender and age asymmetries, the mobility of individuals, and the social ecology of HIV transmission. Whereas it is true that poor individuals and households are likely to be hit harder by the downstream impacts of AIDS, their chances of being exposed to HIV in the first place are not necessarily greater than wealthier individuals or households. What is clear is that approaches to HIV prevention need to cut across all socioeconomic strata of society and they need to be tailored to the specific drivers of transmission within different groups, with particular attention to the vulnerabilities faced by youth and women, and to the dynamic and contextual nature of the relationship between socioeconomic status and HIV.

Behavior, Knowledge, Attitude, and Other Characteristics of Men Who Had Sex With Female Commercial Sex Workers in Kenya

We examined sociodemographic characteristics, knowledge, behavior, and attitude of men who had sex with commercial sex workers (CSWs) in Kenya. About 15% of the men had sex with CSWs. Men who had two or more partners, were away from home five or more times in the past year, and used condoms consistently with their last three partners were likely to have had sex with CSWs (odds ratio [OR] = 2.70, p = .000; OR = 1.43, p = .044; OR = 2.50, p = .000, respectively). Men with better knowledge of HIV/AIDS prevention methods were likely to have had sex with CSWs (OR = 1.62, p = .004). As expected, having had sex with CSWs was associated with higher risk of sexually transmitted infection (OR = 3.62, p = .000). This unexpected association between knowledge and behavior could be bidirectional or reverse causality. Nonetheless, knowledge in prevention has not been translated to practice and change in behavior. These processes require continuous efforts, including assertive campaigns on sexual practices and behaviors.

Circumcision and HIV transmission

PURPOSE OF REVIEW

To review the recent literature on male circumcision and its effect on HIV acquisition.

RECENT FINDINGS

The report from the randomized clinical trial of male circumcision in South Africa demonstrating a 60% protective effect in preventing HIV acquisition provided the first clinical trial evidence of efficacy of male circumcision in protecting men against HIV infection. This protective effect was consistent with both ecological and epidemiologic studies which also show a protective effect of 50-70% in men at high risk for HIV infection. Biological studies also demonstrate an increased number of HIV receptor cells in the mucosa of foreskin providing additional evidence of HIV susceptibility in the uncircumcised male. Male circumcision may also have a beneficial effect in preventing HIV acquisition in women and lowering selected sexually transmitted infections in both sexes.

SUMMARY

The results of two ongoing randomized clinical trials of male circumcision in Kenya and Uganda are awaited with interest, however male circumcision should be carefully considered as a potential public health tool in preventing HIV acquisition. If other trials confirm the results of the South African trial, implementation of this surgical procedure will need to be carefully scaled up and integrated into other prevention programs with emphasis on surgical training, aseptic techniques, acceptability, availability and cultural considerations.