Individual and Population Level Impact of Key HIV Risk Factors on HIV Incidence Rates in Durban, South Africa.
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ABSTRACT:
SUBMITTER: Ramjee G
PROVIDER: S-EPMC4841582 | biostudies-other | 2016
REPOSITORIES: biostudies-other
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Project description:BACKGROUND:Little is known about contextual factors that predict long-term mortality following HIV testing in resource-limited settings. We evaluated the impact of contextual factors on 5-year mortality among HIV-infected and HIV-uninfected individuals in Durban, South Africa. METHODS:We used data from the Sizanani trial (NCT01188941) in which adults (?18y) were enrolled prior to HIV testing at 4 outpatient sites. We ascertained vital status via the South African National Population Register. We used random survival forests to identify the most influential predictors of time to death and incorporated these into a Cox model that included age, gender, HIV status, CD4 count, healthcare usage, health facility type, mental health, and self-identified barriers to care (i.e., service delivery, financial, logistical, structural and perceived health). RESULTS:Among 4816 participants, 39% were HIV-infected. Median age was 31y and 49% were female. 380 of 2508 with survival information (15%) died during median follow-up of 5.8y. For both HIV-infected and HIV-uninfected participants, each additional barrier domain increased the HR of dying by 11% (HR 1.11, 95% CI 1.05-1.18). Every 10-point increase in mental health score decreased the HR by 7% (HR 0.93, 95% CI 0.89-0.97). The hazard ratio (HR) for death of HIV-infected versus HIV-uninfected varied by age: HR of 6.59 (95% CI: 4.79-9.06) at age 20 dropping to a HR of 1.13 (95% CI: 0.86-1.48) at age 60. CONCLUSIONS:Independent of serostatus, more self-identified barrier domains and poorer mental health increased mortality risk. Additionally, the impact of HIV on mortality was most pronounced in younger persons. These factors may be used to identify high-risk individuals requiring intensive follow up, regardless of serostatus. TRIAL REGISTRATION:Clinical Trials.gov Identifier NCT01188941. Registered 26 August 2010.
| S-EPMC6712739 | biostudies-literature
Project description:Couples' voluntary HIV counseling and testing (CVCT) significantly decreases HIV transmission within couples, the largest risk group in sub-Saharan Africa, but it is not currently offered in most HIV testing facilities. To roll out such an intervention, understanding locale-specific knowledge barriers is critical. In this study, we measured knowledge of HIV serodiscordance, transmission, and prevention before and after receipt of CVCT services in Durban.Pre- and post-CVCT knowledge surveys were administered to a selection of individuals seeking CVCT services.Changes in knowledge scores were assessed with McNemar Chi-square tests for balanced data and generalized estimating equation methods for unbalanced data.The survey included 317 heterosexual black couples (634 individuals) who were primarily Zulu (87%), unemployed (47%), and had at least a secondary level education (78%). 28% of couples proved to be discordant. Only 30% of individuals thought serodiscordance between couples was possible pre-CVCT compared to 95% post-CVCT. One-third thought there was at least one benefit of CVCT pre-CVCT, increasing to 96% post-CVCT. Overall, there were positive changes in knowledge about HIV transmission and prevention. However, many respondents thought all HIV positive mothers give birth to babies with AIDS (64% pre-CVCT, 59% post-CVCT) and that male circumcision does not protect negative men against HIV (70% pre-CVCT, 67% post-CVCT).CVCT was well received and was followed by improvements in understanding of discordance, the benefits of joint testing, and HIV transmission. Country-level health messaging would benefit from targeting gaps in knowledge about serodiscordance, vertical transmission, and male circumcision.
| S-EPMC4403857 | biostudies-other
Project description:BackgroundFine scale geospatial analysis of HIV infection patterns can be used to facilitate geographically targeted interventions. Our objective was to use the geospatial technology to map age and time standardized HIV incidence rates over a period of 10 years to identify communities at high risk of HIV in the greater Durban area.MethodsHIV incidence rates from 7557 South African women enrolled in five community-based HIV prevention trials (2002-2012) were mapped using participant household global positioning system (GPS) coordinates. Age and period standardized HIV incidence rates were calculated for 43 recruitment clusters across greater Durban. Bayesian conditional autoregressive areal spatial regression (CAR) was used to identify significant patterns and clustering of new HIV infections in recruitment communities.ResultsThe total person-time in the cohort was 9093.93 years and 613 seroconversions were observed. The overall crude HIV incidence rate across all communities was 6·74 per 100PY (95% CI: 6·22-7·30). 95% of the clusters had HIV incidence rates greater than 3 per 100PY. The CAR analysis identified six communities with significantly high HIV incidence. Estimated relative risks for these clusters ranged from 1.34 to 1.70. Consistent with these results, age standardized HIV incidence rates were also highest in these clusters and estimated to be 10 or more per 100 PY. Compared to women 35+ years old younger women were more likely to reside in the highest incidence areas (aOR: 1·51, 95% CI: 1·06-2·15; aOR: 1.59, 95% CI: 1·19-2·14 and aOR: 1·62, 95% CI: 1·2-2·18 for < 20, 20-24, 25-29 years old respectively). Partnership factors (2+ sex partners and being unmarried/not cohabiting) were also more common in the highest incidence clusters (aOR 1.48, 95% CI: 1.25-1.75 and aOR 1.54, 95% CI: 1.28-1.84 respectively).ConclusionFine geospatial analysis showed a continuous, unrelenting, hyper HIV epidemic in most of the greater Durban region with six communities characterised by particularly high levels of HIV incidence. The results motivate for comprehensive community-based HIV prevention approaches including expanded access to PrEP. In addition, a higher concentration of HIV related services is required in the highest risk communities to effectively reach the most vulnerable populations.
| S-EPMC6555962 | biostudies-literature
Project description:BACKGROUND:RV144 is to date the only HIV vaccine trial to demonstrate efficacy, albeit rapidly waning over time. The HVTN 702 trial is currently evaluating in South Africa a similar vaccine formulation to that of RV144 for subtype C HIV with additional boosters (pox-protein regimen). Using a detailed stochastic individual-based network model of disease transmission calibrated to the HIV epidemic, we investigate population-level impact and maximum cost of an HIV vaccine to remain cost-effective. METHODS:Consistent with the original pox-protein regimen, we model a primary series of five vaccinations meeting the goal of 50% cumulative efficacy 24?months after the first dose and include two-yearly boosters that maintain durable efficacy over 10?years. We simulate vaccination programs in South Africa starting in 2027 under various vaccine targeting and HIV treatment and prevention assumptions. RESULTS:Our analysis shows that this partially effective vaccine could prevent, at catch-up vaccination with 60% coverage, up to 941,000 (15.6%) new infections between 2027 and 2047 assuming current trends of antiretroviral treatment. An impact of up to 697,000 (11.5%) infections prevented could be achieved by targeting age cohorts of highest incidence. Economic evaluation indicates that, if treatment scale-up was achieved, vaccination could be cost-effective at a total cost of less than $385 and $62 per 10-year series (cost-effectiveness thresholds of $5,691 and $750). CONCLUSIONS:While a partially effective, rapidly waning vaccine could help to prevent HIV infections, it will not eliminate HIV as a public health priority in sub-Saharan Africa. Vaccination is expected to be most effective under targeted delivery to age groups of highest HIV incidence. Awaiting results of trial, the introduction of vaccination should go in parallel with continued innovation in HIV prevention, including studies to determine the costs of delivery and feasibility and further research into products with greater efficacy and durability.
| S-EPMC6684280 | biostudies-literature
Project description:BACKGROUND:Prompt entry into HIV care is often hindered by personal and structural barriers. Our objective was to evaluate the impact of self-perceived barriers to health care on 1-year mortality among newly diagnosed HIV-infected individuals in Durban, South Africa. METHODS:Before HIV testing at 4 outpatient sites, adults (?18 years) were surveyed regarding perceived barriers to care including (1) service delivery, (2) financial, (3) personal health perception, (4) logistical, and (5) structural. We assessed deaths via phone calls and the South African National Population Register. We used multivariable Cox proportional hazards models to determine the association between number of perceived barriers and death within 1 year. RESULTS:One thousand eight hundred ninety-nine HIV-infected participants enrolled. Median age was 33 years (interquartile range: 27-41 years), 49% were females, and median CD4 count was 192/?L (interquartile range: 72-346/?L). One thousand fifty-seven participants (56%) reported no, 370 (20%) reported 1-3, and 460 (24%) reported >3 barriers to care. By 1 year, 250 [13%, 95% confidence interval (CI): 12% to 15%] participants died. Adjusting for age, sex, education, baseline CD4 count, distance to clinic, and tuberculosis status, participants with 1-3 barriers (adjusted hazard ratio: 1.49, 95% CI: 1.06 to 2.08) and >3 barriers (adjusted hazard ratio: 1.81, 95% CI: 1.35 to 2.43) had higher 1-year mortality risk compared with those without barriers. CONCLUSIONS:HIV-infected individuals in South Africa who reported perceived barriers to medical care at diagnosis were more likely to die within 1 year. Targeted structural interventions, such as extended clinic hours, travel vouchers, and streamlined clinic operations, may improve linkage to care and antiretroviral therapy initiation for these people.
| S-EPMC5321110 | biostudies-literature
Project description:ObjectivesWe investigate the effect of immediate antiretroviral therapy (ART) eligibility on HIV incidence among HIV-uninfected household members.DesignRegression discontinuity study arising from a population-based cohort.MethodsHousehold members of patients seeking care at the Hlabisa HIV Treatment and Care Programme in rural KwaZulu-Natal South Africa between January 2007 and August 2011 with CD4 cell counts up to 350 cells/μl were eligible for inclusion if they had at least two HIV tests and were HIV-uninfected at the time the index patient linked to care (N = 4115). Regression discontinuity was used to assess the intention-to-treat effect of immediate versus delayed ART eligibility on HIV incidence among household members. Exploiting the CD4 cell count-based threshold rule for ART initiation (CD4 < 200 cells/μl until August 2011), we used Cox proportional hazards models to compare outcomes for household members of patients who presented for care with CD4 cell counts just above versus just below the ART initiation threshold.ResultsCharacteristics of household members of index patients initiating HIV care were balanced between those with an index patient immediately eligible for ART (N = 2489) versus delayed for ART (N = 1626). There were 337 incident HIV infections among household members, corresponding to an HIV incidence of 2.4 infections per 100 person-years (95% confidence interval 2.5-3.1). Immediate eligibility for treatment reduced HIV incidence in households by 47% in our optimal estimate (hazard ratio = 0.53, 95% confidence interval 0.30-0.96), and by 32-60% in alternate specifications of the model.ConclusionImmediate eligibility of ART led to substantial reductions in household-level HIV incidence.
| S-EPMC5832606 | biostudies-literature
Project description:Objectives To investigate the impact of early sexual debut on HIV seroprevalence and incidence rates among a cohort of women. Design Prospective study. Setting KwaZulu-Natal, South Africa. Participants A total of 3492 sexually active women who consented to screen a HIV prevention trial during September 2002 to September 2005; a total of 1485 of them were followed for approximately 24 months. Primary and secondary outcome measures HIV seroprevalence among those who were screened for the trial and HIV seroconversion among those who seroconverted during the study. Results Lowest quintiles of age at sexual debut, less than high school education, a higher number of lifetime sexual partners and lack of cohabitation, being diagnosed as having herpes simplex virus 2 and other sexually transmitted infections were all significantly associated with prevalent HIV infection in multivariate analysis. During follow-up, 148 (6.8 per 100 person-years, 95% CI 5.8 to 8.0) women seroconverted. Highest seroconversion rate was observed among women who had reported to have had sex 15 years or younger (12.0 per 100 person-years, 95% CI 8.0 to 18.0). Overall, impact of risk factors considered in this study was associated with considerable potential reductions in HIV prevalence and incidence rates (population attributable risk: 85%, 95% CI 84% to 87% and population attributable risk: 77%, 95% CI 72% to 82%, respectively). Conclusions The association of HIV status with younger age at sexual debut may likely due to an increased number of lifetime partners. This increase could result from longer duration of sexual life. Prevention of HIV infection should include efforts to delay age at first sex in young women. Trial registration number NCT00121459.
| S-EPMC3253418 | biostudies-literature
Project description:IntroductionThere is a notable absence of consensus on how to generate estimates of population-level incidence. Incidence is a considerably more sensitive indicator of epidemiological trends than prevalence, but is harder to estimate. We used a novel hybrid method to estimate HIV incidence by age and sex in a rural district of KwaZulu-Natal, South Africa.MethodsOur novel method uses an 'optimal weighting' of estimates based on an implementation of a particular 'synthetic cohort' approach (interpreting the age/time structure of prevalence, in conjunction with estimates of excess mortality) and biomarkers of 'recent infection' (combining Lag-Avidity, Bio-Rad Avidity and viral load results to define recent infection, and adapting the method for age-specific incidence estimation). Data were obtained from a population-based cross-sectional HIV survey conducted in Mbongolwane and Eshowe health service areas in 2013.ResultsUsing the combined method, we find that age-specific HIV incidence in females rose rapidly during adolescence, from 1.33 cases/100 person-years (95% CI: 0.98,1.67) at age 15 to a peak of 5.01/100PY (4.14,5.87) at age 23. In males, incidence was lower, 0.34/100PY (0.00-0.74) at age 15, and rose later, peaking at 3.86/100PY (2.52-5.20) at age 30. Susceptible population-weighted average incidence in females aged 15-29 was estimated at 3.84/100PY (3.36-4.40), in males aged 15-29 at 1.28/100PY (0.68-1.50) and in all individuals aged 15-29 at 2.55/100PY (2.09-2.76). Using the conventional recency biomarker approach, we estimated HIV incidence among females aged 15-29 at 2.99/100PY (1.79-4.36), among males aged 15-29 at 0.87/100PY (0.22-1.60) and among all individuals aged 15-59 at 1.66/100PY (1.13-2.27).DiscussionHIV incidence was very high in women aged 15-30, peaking in the early 20s. Men had lower incidence, which peaked at age 30. The estimates obtained from the hybrid method are more informative than those produced by conventional analysis of biomarker data, and represents a more optimal use of available data than either the age-continuous biomarker or synthetic cohort methods alone. The method is mainly useful at younger ages, where excess mortality is low and uncertainty in the synthetic cohort estimates is reasonably small.ConclusionApplication of this method to large-scale population-based HIV prevalence surveys is likely to result in improved incidence surveillance over methods currently in wide use. Reasonably accurate and precise age-specific estimates of incidence are important to target better prevention, diagnosis and care strategies.
| S-EPMC6136757 | biostudies-literature
Project description:Background:Population growth at all scales and rapid rates of urbanization, particularly in the global South, are placing increasing pressure on ecosystems and their ability to provide services essential for human well-being. The spatial consideration of threats to ecosystem services related to changes in land use is necessary in order to avoid undue impacts on society due to the loss or reduced supply of ecosystem services. This study assesses the potential threats of land use change from strategic and local development proposals to ecosystem services in the city of Durban. Methods:We analysed the spatial relationship between five categories of ecosystem service hotspots (carbon storage, water yield, sediment retention, nutrient retention and flood attenuation) and urban land use change related to selected strategic planning proposals, development proposals and sand-mining applications in Durban, South Africa (eThekwini Municipality) with a view to determining the consequences for progress towards a more sustainable development path in the city. We identified the potential levels of threat related to habitat destruction or transformation for the five categories of ecosystem services and a subset of 13 ecosystem service hotspots, using GIS spatial analysis tools. Results:The results show that on average, should Durban's strategic development plans be realised, approximately 42% loss of ecosystem service hotspots is expected in the two municipal town-planning regions assessed. With respect to development applications between 2009 and 2012, approximately 36% of all environmental impact assessments and 84% of sand mining applications occurred within ecosystem service hotspots within Durban. Discussion:The findings highlight the tension between short-term development pressures and longer-term sustainability goals and confirm that current planning and development proposals pose a threat to ecosystems and their ability to deliver services that support human well-being in Durban. We suggest practical solutions to include ecosystem services into local government decision-making.
| S-EPMC6204817 | biostudies-literature
Project description:Although many African countries have achieved high levels of HIV diagnosis, funding constraints have necessitated greater focus on more efficient testing approaches. We compared the impact and cost-effectiveness of several potential new testing strategies in South Africa, and assessed the prospects of achieving the UNAIDS target of 95% of HIV-positive adults diagnosed by 2030. We developed a mathematical model to evaluate the potential impact of home-based testing, mobile testing, assisted partner notification, testing in schools and workplaces, and testing of female sex workers (FSWs), men who have sex with men (MSM), family planning clinic attenders and partners of pregnant women. In the absence of new testing strategies, the diagnosed fraction is expected to increase from 90.6% in 2020 to 93.8% by 2030. Home-based testing combined with self-testing would have the greatest impact, increasing the fraction diagnosed to 96.5% by 2030, and would be highly cost-effective compared to currently funded HIV interventions, with a cost per life year saved (LYS) of $394. Testing in FSWs and assisted partner notification would be cost-saving; the cost per LYS would also be low in the case of testing MSM ($20/LYS) and self-testing by partners of pregnant women ($130/LYS).
| S-EPMC6718403 | biostudies-literature