Do HIV prevalence trends in antenatal clinic surveillance represent trends in the general population in the antiretroviral therapy era? The case of Manicaland, East Zimbabwe.

OBJECTIVE: National estimates of HIV trends in generalized epidemics rely on HIV prevalence data from antenatal clinic (ANC) surveillance. We investigate whether HIV prevalence trends in ANC data reflect trends in men and women in the general population during the scale-up of antiretroviral therapy (ART) in Manicaland, Zimbabwe. METHODS: Trends in HIV prevalence in local ANC attendees and adults aged 15-49 years in towns, agricultural estates, and villages were compared using five rounds of parallel ANC (N = 1200) and general-population surveys (N = 10 000) and multivariable log-linear regression. Changes in the age pattern of HIV prevalence and the age distribution of ANC attendees were compared with those in the general population. Age-specific pregnancy prevalence rates were compared by HIV infection and ART status. RESULTS: Cumulatively, from 1998-2000 to 2009-2011, HIV prevalence fell by 60.0% (95% confidence interval, 51.1-67.3%) in ANC surveillance data and by 34.3% (30.8-37.7%) in the general population. Most of the difference arose following the introduction of ART (2006-2011). The estates and villages reflected this overall pattern but HIV prevalence in the towns was lower at local ANCs than in the general population, largely because of attendance by pregnant women from outlying (lower prevalence) areas. The ageing of people living with HIV in the general population (52.4% aged >35 years, 2009-2011) was under-represented in the ANC data (12.6%) because of lower fertility in older and HIV-infected women. CONCLUSION: After the introduction of ART in Manicaland, HIV prevalence declined more steeply in ANC surveillance data than in the general population. Models used for HIV estimates must reflect this change in bias.

Effects of cash transfers on Children's health and social protection in Sub-Saharan Africa: differences in outcomes based on orphan status and household assets.

BACKGROUND: Unconditional and conditional cash transfer programmes (UCT and CCT) show potential to improve the well-being of orphans and other children made vulnerable by HIV/AIDS (OVC). We address the gap in current understanding about the extent to which household-based cash transfers differentially impact individual children's outcomes, according to risk or protective factors such as orphan status and household assets. METHODS: Data were obtained from a cluster-randomised controlled trial in eastern Zimbabwe, with random assignment to three study arms - UCT, CCT or control. The sample included 5,331 children ages 6-17 from 1,697 households. Generalized linear mixed models were specified to predict OVC health vulnerability (child chronic illness and disability) and social protection (birth registration and 90% school attendance). Models included child-level risk factors (age, orphan status); household risk factors (adults with chronic illnesses and disabilities, greater household size); and household protective factors (including asset-holding). Interactions were systematically tested. RESULTS: Orphan status was associated with decreased likelihood for birth registration, and paternal orphans and children for whom both parents' survival status was unknown were less likely to attend school. In the UCT arm, paternal orphans fared better in likelihood of birth registration compared with non-paternal orphans. Effects of study arms on outcomes were not moderated by any other risk or protective factors. High household asset-holding was associated with decreased likelihood of child's chronic illness and increased birth registration and school attendance, but household assets did not moderate the effects of cash transfers on risk or protective factors. CONCLUSION: Orphaned children are at higher risk for poor social protection outcomes even when cared for in family-based settings. UCT and CCT each produced direct effects on children's social protection which are not moderated by other child- and household-level risk factors, but orphans are less likely to attend school or obtain birth registration. The effects of UCT and CCT are not moderated by asset-holding, but greater household assets predict greater social protection outcomes. Intervention efforts need to focus on ameliorating the additional risk burden carried by orphaned children. These efforts might include caregiver education, and additional incentives based on efforts made specifically for orphaned children.

Grassroots community organizations' contribution to the scale-up of HIV testing and counselling services in Zimbabwe.

OBJECTIVE: To investigate whether community engagement (participation in grassroots organizations) contributed to increases in HIV testing in Zimbabwe. METHODS: Prospective data on membership of local community organizations (e.g. women's groups and burial societies) and uptake of HIV testing and counselling (HTC) and prevention-of-mother-to-child transmission (PMTCT) services were collected from 5260 adults interviewed in two consecutive rounds of a general-population cohort survey in eastern Zimbabwe between 2003 and 2008. The effects of community engagement on uptake of services during the follow-up period were measured using logistic regression to adjust for observed confounding factors. RESULTS: Sixteen percent of men and 47% of women were consistent members of community organizations; 58 and 35% of these people discussed HIV in their meetings and were members of externally sponsored organizations, respectively. Fewer men (10.1%) than women (32.4%) took up HTC during follow-up [adjusted odds ratio (aOR)=4.08, 95% confidence interval (CI) 3.43-4.86, P<0.001]. HTC uptake was higher for members of community organizations than for nonmembers: men, 15.0 versus 9.2% (1.67, 1.15-2.43, P=0.007); women, 35.6 versus 29.6% (1.26, 1.06-1.49, P=0.008). Membership of community organizations showed a nonsignificant association with PMTCT uptake amongst recently pregnant women (42.3 versus 34.2%; 1.30, 0.94-1.78, P=0.1). The most consistent positive associations between community participation and HTC and PMTCT uptake were found in organizations that discussed HIV and when external sponsorship was absent. CONCLUSION: Grassroots organizations contributed to increased uptake of HTC services in eastern Zimbabwe in the mid-2000s. Partnerships with these organizations could harness community support for the further increases in HIV testing needed in sub-Saharan Africa.

Increasing adolescent HIV prevalence in Eastern Zimbabwe--evidence of long-term survivors of mother-to-child transmission?

Recent data from the Manicaland HIV/STD Prevention Project, a general-population open HIV cohort study, suggested that between 2004 and 2007 HIV prevalence amongst males aged 15-17 years in eastern Zimbabwe increased from 1.20% to 2.23%, and in females remained unchanged at 2.23% to 2.39%, while prevalence continued to decline in the rest of the adult population. We assess whether the more likely source of the increase in adolescent HIV prevalence is recent sexual HIV acquisition, or the aging of long-term survivors of perinatal HIV acquisition that occurred during the early growth of the epidemic. Using data collected between August 2006 and November 2008, we investigated associations between adolescent HIV and (1) maternal orphanhood and maternal HIV status, (2) reported sexual behaviour, and (3) reporting recurring sickness or chronic illness, suggesting infected adolescents might be in a late stage of HIV infection. HIV-infected adolescent males were more likely to be maternal orphans (RR = 2.97, p<0.001) and both HIV-infected adolescent males and females were more likely to be maternal orphans or have an HIV-infected mother (male RR = 1.83, p<0.001; female RR = 16.6, p<0.001). None of 22 HIV-infected adolescent males and only three of 23 HIV-infected females reported ever having had sex. HIV-infected adolescents were 60% more likely to report illness than HIV-infected young adults. Taken together, all three hypotheses suggest that recent increases in adolescent HIV prevalence in eastern Zimbabwe are more likely attributable to long-term survival of mother-to-child transmission rather than increases in risky sexual behaviour. HIV prevalence in adolescents and young adults cannot be used as a surrogate for recent HIV incidence, and health systems should prepare for increasing numbers of long-term infected adolescents.

Asset ownership among households caring for orphans and vulnerable children in rural Zimbabwe: the influence of ownership on children's health and social vulnerabilities.

The high prevalence of human immunodeficiency virus/acquired immune deficiency syndrome in sub-Saharan Africa has resulted in a dramatic increase in orphans and vulnerable children (OVC) over the past decade. These children typically rely on extended family networks for support, but the magnitude of the crisis has resulted in traditional familial networks becoming overwhelmed and more economically and socially vulnerable. Previous research consistently demonstrates the positive influence of household asset ownership on children's well-being. Using data from impoverished households caring for OVC in rural Manicaland Province, Zimbabwe, this study explores the influence of household asset ownership on OVC health vulnerability (HV) and social vulnerability (SV). Findings indicate that asset ownership is associated with significantly lower SV, in terms of school attendance and birth registration. Yet, assets do not emerge as a direct influence of OVC HV as measured by disease and chronic illness, although having a chronically ill adult in the household increases HV. These findings suggest that asset ownership, specifically a combination of fixed and movable assets, may offset the influence of other risk factors for children's SV.

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.

Measuring and correcting biased child mortality statistics in countries with generalized epidemics of HIV infection.

OBJECTIVE: Under Millennium Development Goal 4, countries are required to reduce child mortality by two-thirds between 1990 and 2015. In countries with generalized epidemics of human immunodeficiency virus (HIV) infection, standard statistics based on fertility history may misrepresent progress towards this target owing to the correlation between deaths among mothers and early childhood deaths from acquired immunodeficiency syndrome. METHODS: To empirically estimate this bias, child mortality data and fertility history, including births to deceased women, were collected through prospective household surveys in eastern Zimbabwe during 1998-2005. A mathematical model was then used to investigate the determinants and temporal dynamics of the bias, first in Zimbabwe and then in other countries with different background mortality rates and HIV-related epidemic profiles. FINDINGS: According to the empirical data, standard cross-sectional survey statistics underestimated true infant and under-5 mortality by 6.7% and 9.8%, respectively. These estimates were in agreement with the output from the model, in which the bias varied according to the magnitude and stage of the epidemic of HIV infection and background mortality rates. The bias was greater the longer the period elapsed before the survey and in later stages of the epidemic. Bias could substantially distort the measured effect of interventions to reduce non-HIV-related mortality and of programmes to prevent mother-to-child transmission, especially when trends are based on data from a single survey. CONCLUSION: The correlation between the HIV-related deaths of mothers and their children can bias survey estimates of early child mortality. A mathematical model with a user-friendly interface is available to correct for this bias when measuring progress towards Millennium Development Goal 4 in countries with generalized epidemics of HIV infection.

HIV-associated orphanhood and children's psychosocial distress: theoretical framework tested with data from Zimbabwe.

OBJECTIVES: We measured the psychosocial effect of orphanhood in a sub-Saharan African population and evaluated a new framework for understanding the causes and consequences of psychosocial distress among orphans and other vulnerable children. METHODS: The framework was evaluated using data from 5321 children aged 12 to 17 years who were interviewed in a 2004 national survey in Zimbabwe. We constructed a measure of psychosocial distress using principle components analysis. We used regression analyses to obtain standardized parameter estimates of psychosocial distress and odds ratios of early sexual activity. RESULTS: Orphans had more psychosocial distress than did nonorphans. For both genders, paternal, maternal, and double orphans exhibited more-severe distress than did nonorphaned, nonvulnerable children. Orphanhood remained associated with psychosocial distress after we controlled for differences in more-proximate determinants. Maternal and paternal orphans were significantly more likely than were nonorphaned, nonvulnerable children to have engaged in sexual activity. These differences were reduced after we controlled for psychosocial distress. CONCLUSIONS: Orphaned adolescents in Zimbabwe suffer greater psychosocial distress than do nonorphaned, nonvulnerable children, which may lead to increased likelihood of early onset of sexual intercourse and HIV infection. The effect of strategies to provide psychosocial support should be evaluated scientifically.

Impact and process evaluation of integrated community and clinic-based HIV-1 control: a cluster-randomised trial in eastern Zimbabwe.

BACKGROUND: HIV-1 control in sub-Saharan Africa requires cost-effective and sustainable programmes that promote behaviour change and reduce cofactor sexually transmitted infections (STIs) at the population and individual levels. METHODS AND FINDINGS: We measured the feasibility of community-based peer education, free condom distribution, income-generating projects, and clinic-based STI treatment and counselling services and evaluated their impact on the incidence of HIV-1 measured over a 3-y period in a cluster-randomised controlled trial in eastern Zimbabwe. Analysis of primary outcomes was on an intention-to-treat basis. The income-generating projects proved impossible to implement in the prevailing economic climate. Despite greater programme activity and knowledge in the intervention communities, the incidence rate ratio of HIV-1 was 1.27 (95% confidence interval [CI] 0.92-1.75) compared to the control communities. No evidence was found for reduced incidence of self-reported STI symptoms or high-risk sexual behaviour in the intervention communities. Males who attended programme meetings had lower HIV-1 incidence (incidence rate ratio 0.48, 95% CI 0.24-0.98), and fewer men who attended programme meetings reported unprotected sex with casual partners (odds ratio 0.45, 95% CI 0.28-0.75). More male STI patients in the intervention communities reported cessation of symptoms (odds ratio 2.49, 95% CI 1.21-5.12). CONCLUSIONS: Integrated peer education, condom distribution, and syndromic STI management did not reduce population-level HIV-1 incidence in a declining epidemic, despite reducing HIV-1 incidence in the immediate male target group. Our results highlight the need to assess the community-level impact of interventions that are effective amongst targeted population sub-groups.

Age at first sex and HIV infection in rural Zimbabwe.

Beginning sexual activity introduces an individual to the risk of acquiring sexually transmitted infections. In this study, cross-sectional behavioral data linked to HIV-status from 4,138 men and 4,948 women interviewed in rural Zimbabwe are analyzed to investigate the distribution and consequences of early first sex. We find that age at first sex (at a median age of 19 years for males and 18 years for females) has declined among males over the past 30 years but increased recently among females. Those in unskilled employment, those not associated with a church, and women without a primary education begin to have sex earlier than others. Early sexual debut before marriage precedes a lifetime of greater sexual activity but with more consistent condom use. Women who begin to have sex earlier than others of their age are more likely to be infected with HIV. This finding can be explained by their having a greater lifetime number of sexual partners than those whose first sexual experience occurs later.

HIV decline associated with behavior change in eastern Zimbabwe.

Few sub-Saharan African countries have witnessed declines in HIV prevalence, and only Uganda has compelling evidence for a decline founded on sexual behavior change. We report a decline in HIV prevalence in eastern Zimbabwe between 1998 and 2003 associated with sexual behavior change in four distinct socioeconomic strata. HIV prevalence fell most steeply at young ages-by 23 and 49%, respectively, among men aged 17 to 29 years and women aged 15 to 24 years-and in more educated groups. Sexually experienced men and women reported reductions in casual sex of 49 and 22%, respectively, whereas recent cohorts reported delayed sexual debut. Selective AIDS-induced mortality contributed to the decline in HIV prevalence.

Beer halls as a focus for HIV prevention activities in rural Zimbabwe.

OBJECTIVE: The authors conducted an assessment of the role of beer halls in the HIV epidemic of rural Zimbabwe as part of the ongoing identification of risky places for the targeting of prevention activities. STUDY: A population-based survey of 9480 adults collected data on number of visits to beer halls in the last month, together with sociodemographics, sexual behavior, and HIV infection from 1998-2000. RESULTS: Fifty percent of men, but only 4% of women, had been to a beer hall in the last month. They reported higher levels of sexual behavior and stronger associations with commercial sex than those who had not been to a beer hall. A recent visit to a beer hall was also associated with HIV infection (men: odds ratio [OR] = 1.9, P <0.001; women: OR = 1.7, P = 0.001) and with ever having experienced urethral/vaginal discharge or genital sores. Only 225 respondents experienced an HIV prevention activity at a beer hall in the last 6 months. CONCLUSIONS: Beer hall attendance is associated with high-risk behavior for HIV infection and cofactor sexually transmitted infections. Beer halls represent an underused focus for HIV prevention.

Scale-free networks and sexually transmitted diseases: a description of observed patterns of sexual contacts in Britain and Zimbabwe.

BACKGROUND: Sexually transmitted infections spread through a network of contacts created by the formation of sexual partnerships. In physics, networks have been characterized as "scale-free" if they follow a power law with an exponent between 2 and 3. OBJECTIVE: The objective of this study was to test statistically whether distributions of numbers of sexual partners reported from different populations are well described by power laws. STUDY DESIGN: Power laws and an exponential null model are fitted by maximum likelihood techniques to reported distributions of numbers of partners. Data are taken from 4 population-based surveys, 3 from Britain and 1 from rural Zimbabwe. RESULTS: The networks can be described by power laws over a number of orders of magnitude. In addition, the derived exponents differ significantly and meaningfully, with an "accelerating network" formed between men who have sex with men (MSM). CONCLUSIONS: A scale-free network approach provides a reasonable description of distributions of reported numbers of sexual partners.

Methods to reduce social desirability bias in sex surveys in low-development settings: experience in Zimbabwe.

BACKGROUND: Social desirability bias hampers measurement of risk behavior for acquiring STDs and evaluation of control interventions. More confidential data collection methods reduce this bias in Western countries but generally require technology not available in less developed settings. GOAL The goal of this report was to describe and evaluate an informal, confidential, low-technology method-Informal Confidential Voting Interviews (ICVIs)-for collecting sexual behavior data in less developed settings. STUDY DESIGN: Reports of multiple sex partners by sexually active, basic-literate, population-based survey participants in rural Zimbabwe randomly assigned to ICVIs and face-to-face interviews (FTFIs) were compared. RESULTS: Ninety-two percent of respondents (n = 7,823) were sufficiently literate for ICVIs. Error rates were low but higher than in FTFIs. More male and female ICVI respondents interviewed reported multiple current sex partners (OR = 1.33 and 5.24, respectively) and multiple partners in the past month (OR = 1.71 and 2.92) and the past year (OR = 1.35 and 1.97). CONCLUSION: The ICVI method appears to reduce bias but requires further evaluation to assess viability and effect in alternative settings.

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

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