HIV decline in Zimbabwe due to reductions in risky sex? Evidence from a comprehensive epidemiological review.

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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

Steep HIV prevalence declines among young people in selected Zambian communities: population-based observations (1995–2003)

BACKGROUND: Understanding the epidemiological HIV context is critical in building effective setting-specific preventive strategies. We examined HIV prevalence patterns in selected communities of men and women aged 15–59 years in Zambia. METHODS: Population-based HIV surveys in 1995 (n = 3158), 1999 (n = 3731) and 2003 (n = 4751) were conducted in selected communities using probability proportional to size stratified random-cluster sampling. Multivariate logistic regression and trend analyses were stratified by residence, sex and age group. Absence, <30% in men and <15% in women in all rounds, was the most important cause of non-response. Saliva was used for HIV testing, and refusal was <10%. RESULTS: Among rural groups aged 15–24 years, prevalence declined by 59.2% (15.7% to 6.4%, P < 0.001) in females and by 44.6% (5.6% to 3.1%, P < 0.001) in males. In age-group 15–49 years, declines were less than 25%. In the urban groups aged 15–24, prevalence declined by 47% (23.4% to 12.4%, P < 0.001) among females and 57.3% (7.5% to 3.2%, P = 0.001) among males but were 32% and 27% in men and women aged 15–49, respectively. Higher educated young people in 2003 had lower odds of infection than in 1995 in both urban [men: AOR 0.29(95%CI 0.14–0.60); women: AOR 0.38(95%CI 0.19–0.79)] and rural groups [men: AOR 0.16(95%CI 0.11–0.25), women: AOR 0.10(95%CI 0.01–7.34)]. Although higher mobility was associated with increased likelihood of infection in men overall, AOR, 1.71(95%CI 1.34–2.19), prevalence declined in mobile groups also (OR 0.52 95%CI 0.31–0.88). In parallel, urban young people with ≥11 school years were more likely to use condoms during the last casual sex (OR 2.96 95%CI 1.93–4.52) and report less number of casual sexual partners (AOR 0.33 95%CI 0.19–0.56) in the last twelve months than lower educated groups. CONCLUSION: Steep HIV prevalence declines in young people, suggesting continuing declining incidence, were masked by modest overall declines. The concentration of declines in higher educated groups suggests a plausible association with behavioural change

Assessing adult mortality in HIV-1-afflicted Zimbabwe (1998 -2003).

OBJECTIVE: To compare alternative methods to vital registration systems for estimating adult mortality, and describe patterns of mortality in Manicaland, Zimbabwe, which has been severely affected by HIV. METHODS: We compared estimates of adult mortality from (1) a single question on household mortality, (2) repeated household censuses, and (3) an adult cohort study with linked HIV testing from Manicaland, with a mathematical model fitted to local age-specific HIV prevalence (1998 -2000). FINDINGS: The crude death rate from the single question (29 per 1000 person-years) was roughly consistent with that from the mathematical model (22 -25 per 1000 person-years), but much higher than that from the household censuses (12 per 1000 person-years). Adult mortality in the household censuses (males 0.65; females 0.51) was lower than in the cohort study (males 0.77; females 0.57), while mathematical models gave a much higher estimate, especially for females (males 0.80 -0.83; females 0.75 -0.80). The population attributable fraction of adult deaths due to HIV was 0.61 for men and 0.70 for women, with life expectancy estimated to be 34.3 years for males and 38.2 years for females. CONCLUSION: Each method for estimating adult mortality had limitations in terms of loss to follow-up (cohort study), under-ascertainment (household censuses), transparency of underlying processes (single question), and sensitivity to parameterization (mathematical model). However, these analyses make clear the advantages of longitudinal cohort data, which provide more complete ascertainment than household censuses, highlight possible inaccuracies in model assumptions, and allow direct quantification of the impact of HIV

Assessing adult mortality in HIV-1-afflicted Zimbabwe (1998 -2003)

OBJECTIVE: To compare alternative methods to vital registration systems for estimating adult mortality, and describe patterns of mortality in Manicaland, Zimbabwe, which has been severely affected by HIV. METHODS: We compared estimates of adult mortality from (1) a single question on household mortality, (2) repeated household censuses, and (3) an adult cohort study with linked HIV testing from Manicaland, with a mathematical model fitted to local age-specific HIV prevalence (1998 -2000). FINDINGS: The crude death rate from the single question (29 per 1000 person-years) was roughly consistent with that from the mathematical model (22 -25 per 1000 person-years), but much higher than that from the household censuses (12 per 1000 person-years). Adult mortality in the household censuses (males 0.65; females 0.51) was lower than in the cohort study (males 0.77; females 0.57), while mathematical models gave a much higher estimate, especially for females (males 0.80 -0.83; females 0.75 -0.80). The population attributable fraction of adult deaths due to HIV was 0.61 for men and 0.70 for women, with life expectancy estimated to be 34.3 years for males and 38.2 years for females. CONCLUSION: Each method for estimating adult mortality had limitations in terms of loss to follow-up (cohort study), under-ascertainment (household censuses), transparency of underlying processes (single question), and sensitivity to parameterization (mathematical model). However, these analyses make clear the advantages of longitudinal cohort data, which provide more complete ascertainment than household censuses, highlight possible inaccuracies in model assumptions, and allow direct quantification of the impact of HIV

Changing patterns of adult mortality as the HIV epidemic matures in Manicaland, eastern Zimbabwe.

BACKGROUND: HIV prevalence declined in Manicaland, eastern Zimbabwe, between 1998 and 2003. During this period, adult mortality in men was stable, whereas female mortality increased to levels similar to those of men. We examine the trends in mortality from 2003 to 2005. METHODS: A population-based cohort was recruited from a household census in 12 communities. A baseline survey was conducted between 1998 and 2000, with the first and second follow-up surveys occurring after 3 and 5 years, respectively. Using checklists of the resident population at the previous round, adult deaths were reported to enumerators by surviving household members or community informants. RESULTS: Age-standardized adult mortality rates for men increased slightly but not significantly over time (1998-2000: 24/1000 person-years; 2001-2002: 26/1000 person-years; 2003-2005: 31/1000 person-years), reflecting a sharp rise in mortality among HIV-positive individuals (62, 79 and 105 per 1000 person-years). Female mortality rose sharply initially but levelled off after 2001 (15, 26 and 26 per 1000 person-years) also caused by the pronounced increase in mortality among HIV-positive women (35, 75 and 88/1000 person-years; 7/1000 person-years for HIV-negative men and women in all periods); 69% of adult male deaths and 74% of adult female deaths were attributable to HIV/AIDS in 2003-2005. In men, mortality was similar and stable in towns, estates, roadside business centres and subsistence farming areas. In women, mortality rose in towns and subsistence farming areas between 1998 and 2002 and was greater in towns than in other locations. CONCLUSION: Recent data indicate that adult mortality may be stabilizing in eastern Zimbabwe after the recent downturn in HIV prevalence

Linking Migration, Mobility and HIV

Population mobility is commonly identified as a key driver of the HIV epidemic, both linking geographically separate epidemics and intensifying transmission through inducing riskier sexual behaviours. However, beyond the well-known case studies of South African miners and East African truck drivers, the evidence on the links between HIV and mobility is nuanced, contradictory and inconclusive and is in part attributed to the abstract definitions of mobility used in different studies. This problematic conception of mobility, with no reference to who moves, their motivations for moving, or the characteristics of sending and receiving areas, can have a dramatic impact on how one understands the influence which this structural factor has on HIV risk in different settings. Future research on mobility and HIV transmission must incorporate an understanding of migration and mobility as dynamic processes and link different patterns and forms of mobility with location-specific sexual networks and HIV epidemiology