25 research outputs found
HIV decline in Zimbabwe due to reductions in risky sex? Evidence from a comprehensive epidemiological review
Background Recent data from antenatal clinic (ANC) surveillance and general population surveys suggest substantial declines in human immunodeficiency virus (HIV) prevalence in Zimbabwe. We assessed the contributions of rising mortality, falling HIV incidence and sexual behaviour change to the decline in HIV prevalence. Methods Comprehensive review and secondary analysis of national and local sources on trends in HIV prevalence, HIV incidence, mortality and sexual behaviour covering the period 1985-2007. Results HIV prevalence fell in Zimbabwe over the past decade (national estimates: from 29.3% in 1997 to 15.6% in 2007). National census and survey estimates, vital registration data from Harare and Bulawayo, and prospective local population survey data from eastern Zimbabwe showed substantial rises in mortality during the 1990s levelling off after 2000. Direct estimates of HIV incidence in male factory workers and women attending pre- and post-natal clinics, trends in HIV prevalence in 15-24-year-olds, and back-calculation estimates based on the vital registration data from Harare indicated that HIV incidence may have peaked in the early 1990s and fallen during the 1990s. Household survey data showed reductions in numbers reporting casual partners from the late 1990s and high condom use in non-regular partnerships between 1998 and 2007. Conclusions These findings provide the first convincing evidence of an HIV decline accelerated by changes in sexual behaviour in a southern African country. However, in 2007, one in every seven adults in Zimbabwe was still infected with a life-threatening virus and mortality rates remained at crisis leve
Estimating the Population Size of Female Sex Workers in Zimbabwe: Comparison of Estimates Obtained Using Different Methods in Twenty Sites and Development of a National-Level Estimate.
BACKGROUND: National-level population size estimates (PSEs) for hidden populations are required for HIV programming and modelling. Various estimation methods are available at the site-level, but it remains unclear which are optimal and how best to obtain national-level estimates. SETTING: Zimbabwe. METHODS: Using 2015-2017 data from respondent-driven sampling (RDS) surveys among female sex workers (FSW) aged 18+ years, mappings, and program records, we calculated PSEs for each of the 20 sites across Zimbabwe, using up to 3 methods per site (service and unique object multipliers, census, and capture-recapture). We compared estimates from different methods, and calculated site medians. We estimated prevalence of sex work at each site using census data available on the number of 15-49-year-old women, generated a list of all "hotspot" sites for sex work nationally, and matched sites into strata in which the prevalence of sex work from sites with PSEs was applied to those without. Directly and indirectly estimated PSEs for all hotspot sites were summed to provide a national-level PSE, incorporating an adjustment accounting for sex work outside hotspots. RESULTS: Median site PSEs ranged from 12,863 in Harare to 247 in a rural growth-point. Multiplier methods produced the highest PSEs. We identified 55 hotspots estimated to include 95% of all FSW. FSW nationally were estimated to number 40,491, 1.23% of women aged 15-49 years, (plausibility bounds 28,177-58,797, 0.86-1.79%, those under 18 considered sexually exploited minors). CONCLUSION: There are large numbers of FSW estimated in Zimbabwe. Uncertainty in population size estimation should be reflected in policy-making
Within-Gender Changes in HIV Prevalence among Adults between 2005/6 and 2010/11 in Zimbabwe
INTRODUCTION: Zimbabwe has reported significant declines in HIV prevalence between 2005/06 and 2010/11 Demography and Health Surveys; a within-gender analysis to identify the magnitude and factors associated with this change, which can be masked, is critical for targeting interventions. METHODS: We analyzed change in HIV prevalence for 6,947 women and 5,848 men in the 2005/06 survey and 7,313 women and 6,250 men in 2010/11 surveys using 2005/06 as referent. The data was analyzed taking into consideration the survey design and therefore the svy, mean command in Stata was used in both linear and logistic regression. RESULTS: There were similar proportional declines in prevalence at national level for males (15% p=0.011) and females (16%,p=0.008). However, there were variations in decline by provincial setting, demographic variables of age, educational level and some sexual risk behaviours. In logistic regression analysis, statistically significant declines were observed among men in Manicaland, Mashonaland East and Harare (p<0.01) and for women in Manicaland, Mashonaland Central and Harare (p<0.01). Although not statistically significant, numerical increases were observed among men in Matebeleland North, Matebeleland South, Midlands and for both men and women in Bulawayo. Young women in the age range 15-34 experienced a decline in prevalence (p<0.01) while older men 30-44 had a statistically significant decline (p<0.01). Having a secondary and above education, regardless of employment status for both men and women recorded a significant decline. For sexual risk behaviours, currently in union for men and women and not in union for women there was a significant decline in prevalence. CONCLUSION: Zimbabwe has reported a significant decline among both men and women but there are important differentials across provinces, demographic characteristics and sexual risk behaviours that suggest that the epidemic in Zimbabwe is heterogeneous and therefore interventions must be targeted in order to achieve epidemic control
Trends in Prevalence of Advanced HIV Disease at Antiretroviral Therapy Enrollment - 10 Countries, 2004-2015.
Monitoring prevalence of advanced human immunodeficiency virus (HIV) disease (i.e., CD4+ T-cell count <200 cells/μL) among persons starting antiretroviral therapy (ART) is important to understand ART program outcomes, inform HIV prevention strategy, and forecast need for adjunctive therapies.*,†,§ To assess trends in prevalence of advanced disease at ART initiation in 10 high-burden countries during 2004-2015, records of 694,138 ART enrollees aged ≥15 years from 797 ART facilities were analyzed. Availability of national electronic medical record systems allowed up-to-date evaluation of trends in Haiti (2004-2015), Mozambique (2004-2014), and Namibia (2004-2012), where prevalence of advanced disease at ART initiation declined from 75% to 34% (p<0.001), 73% to 37% (p<0.001), and 80% to 41% (p<0.001), respectively. Significant declines in prevalence of advanced disease during 2004-2011 were observed in Nigeria, Swaziland, Uganda, Vietnam, and Zimbabwe. The encouraging declines in prevalence of advanced disease at ART enrollment are likely due to scale-up of testing and treatment services and ART-eligibility guidelines encouraging earlier ART initiation. However, in 2015, approximately a third of new ART patients still initiated ART with advanced HIV disease. To reduce prevalence of advanced disease at ART initiation, adoption of World Health Organization (WHO)-recommended "treat-all" guidelines and strategies to facilitate earlier HIV testing and treatment are needed to reduce HIV-related mortality and HIV incidence
Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.
BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)
Evaluation of the Mean Duration of Recent Infection (MDRI) and the False Recent Rate (FRR) for the Limiting Antigen Avidity Enzyme Immune Assay (LAg) and Bio-Rad HIV ½ Plus O Avidity Incidence Assay (BRAI)
Thesis (PhD)--Stellenbosch University, 2017.ENGLISH SUMMARY : Background: The evaluation of laboratory assays in estimating HIV incidence has become a priority because of the complexity of HIV epidemics and the need to measure the impact of public health interventions targeting reduction of HIV incidence. Biomarkers should have test properties that allow the lowest possible False Recent Rate (FRR, or probability of diagnosing a long-term infection as recently infected) over the longest possible period (Mean Duration of Recent Infection or MDRI) during which the case is considered as a recent infection.
Methods: We compared the BED Capture Enzyme Immunoassay (BED), Sedia Limiting Antigen (LAg) and Bio-Rad HIV ½ Plus O Avidity Incidence Assay (BRAI) using samples from a prospective cohort trial, the Zimbabwe Vitamin A for Mothers and Babies Project (ZVITAMBO) 1997–2000. We determined MDRI using 591 samples from 184 seroconverting women, and determined FRR by testing 2825 cases known to be HIV- positive for >12 months. We used these results to estimate HIV incidence over the first 12 months postpartum, and during the period prior to childbirth.
Results: At recommended cut-offs MDRI values were: BRAI, 135 days (120 – 151) at Avidity Index (AI) 30%; LAg, 104 days (98 - 110) at ODn cut-off 1.5; BED, 188 days (180 -196) at ODn cut-off 0.8. All error bounds in this thesis signify 95% confidence intervals. The coefficients of variation (CV) of the MDRI estimates for BRAI, LAg and BED were 5.9%, 2.9% and 2.1%, respectively. Corresponding FRRs were 1.1% (0.7-1.5) for BRAI, 0.6% (0.3-0.9) for LAg and 4.8% (4.1-5.7) for BED. MDRI and FRR estimates, all derived using postpartum women, were lower than in other published studies. Using original ZVITAMBO HIV diagnoses, adjusted HIV incidence over the first 12 months postpartum was estimated as; BRAI, 2.7% (1.8-3.7); LAg, 3.7% (2.7-4.8); BED, 3.6% (2.4 -4.9). Follow-up incidence was 3.4% (3.0-3.8). When cases with viral load <1000 copies/ml were defined as long-term infections, regardless of serological biomarker level, FRRs were; BRAI, 1.0% (0.7-1.5); LAg, 0.2% (0.2 -0.7); BED 3.8% (3.1-4.6). MDRIs were; BRAI, 133 days (113-154); LAg, 101 days (87-115); BED, 177 days (155 - 199). Corresponding incidences, unadjusted for FRR, were: BRAI, 3.9% (2.9-4.9); LAg, 3.1% (2.1-4.0); BED, 6.2 % (5.0-7.3). Adjusted estimates were 2.7% (1.5-4.0), 2.5% (1.6-3.5) and 2.6% (1.6-3.7) respectively. At baseline, with no follow-up estimate for comparison, adjusted incidence for serological biomarkers used alone were; BRAI, 8.1% (6.6-9.7); LAg, 6.9% (5.7-8.1); BED 6.7% (5.5-7.9). When viral load was also used, the adjusted and unadjusted incidence estimates were; BRAI, 7.3% (5.7-8.8) and 8.4% (6.8-10.0); LAg, 5.1% (3.9-6.3) and 5.7% (4.5-6.9); BED, 5.4% (4.1-6.7) and 8.6% (7.3-10.0).
Conclusion: At recommended cut-offs; BRAI FRR was 1.9 times higher than that of LAg. BRAI MDRIs were also 1.3 times higher, but with a relative standard error 2.4 times as high. Postpartum BRAI incidence estimates were consistently lower than follow-up estimates. Adjusted biomarker estimates under-estimated follow-up incidence when we used viral load in combination with either serological test.AFRIKAANSE OPSOMMING : Geen opsomming beskikbaar
Comparison of HIV Prevalence Estimates for Zimbabwe from Antenatal Clinic Surveillance (2006) and the 2005– 06 Zimbabwe Demographic and Health Survey
Objective: To assess whether HIV surveillance data from pregnant women attending antenatal care (ANC) clinics in Zimbabwe represent infection levels in the general population. Methods: HIV prevalence estimates from ANC surveillance sites in 2006 were compared with estimates from the corresponding Zimbabwe Demographic and Health Survey 2005–06 (ZDHS) clusters using geographic information systems. Results: The ANC HIV prevalence estimate (17.9%, 95 % CI 17.0%–18.8%) was similar to the ZDHS estimates for all men and women aged 15–49 years (18.1%, 16.9%–18.8%), for pregnant women (17.5%, 13.9%–21.9%), and for ANC attendees living within 30 km of ANC surveillance sites (19.9%, 17.1%–22.8%). However, the ANC surveillance estimate (17.9%) was lower than the ZDHS estimates for all women (21.1%, 19.7%–22.6%) and for women living within 30 km catchment areas of ANC surveillance sites (20.9%, 19.4%–22.3%). HIV prevalence in ANC sites classified as urban and rural was significantly lower than in sites classified as ‘‘other’’. Conclusions: Periodic population surveys can be used to validate ANC surveillance estimates. In Zimbabwe, ANC surveillance provides reliable estimates of HIV prevalence among men and women aged 15–49 years in the genera
Success in Revitalizing Weekly Disease Surveillance System in Zimbabwe Using Cell-phone Mediated Data Transmission, 2009-2013
Innovative approach to revitalizing Disease Surveillance System in Zimbabwe using cell-phone mediated data transmission has been a huge success. Cell phones have been successfully integrated into disease surveillance system resulting in expansion of surveillance coverage, improved completeness and timeliness. Decision makers are now able to access disease surveillance data in near real-time
Comparison of HIV prevalence in women aged 15–49: ANC sentinel surveillance versus ZDHS, by ANC surveillance site and site classification, 2005–06.
1<p>Women 15–49 interviewed and tested by the ZDHS who live in a community within 30 km from the nearest ANC site.</p><p>Urban, rural, and other designation is based on the classification of the ANC surveillance site attended (for ANC columns) or the nearest ANC surveillance site (for ZDHS columns).</p><p>*: 0–24 unweighted case; (): 25–49 unweighted cases.</p
Success in Revitalizing Weekly Disease Surveillance System in Zimbabwe Using Cell-phone Mediated Data Transmission, 2009-2013
Innovative approach to revitalizing Disease Surveillance System in Zimbabwe using cell-phone mediated data transmission has been a huge success. Cell phones have been successfully integrated into disease surveillance system resulting in expansion of surveillance coverage, improved completeness and timeliness. Decision makers are now able to access disease surveillance data in near real-time