Declines in HIV incidence among men and women in a South African population-based cohort.
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ABSTRACT:
SUBMITTER: Vandormael A
PROVIDER: S-EPMC6889466 | biostudies-literature | 2019 Dec
REPOSITORIES: biostudies-literature
Publications
Declines in HIV incidence among men and women in a South African population-based cohort.
Vandormael Alain A Akullian Adam A Siedner Mark M de Oliveira Tulio T Bärnighausen Till T Tanser Frank F
Nature communications 20191202 1
Over the past decade, there has been a massive scale-up of primary and secondary prevention services to reduce the population-wide incidence of HIV. However, the impact of these services on HIV incidence has not been demonstrated using a prospectively followed, population-based cohort from South Africa-the country with the world's highest rate of new infections. To quantify HIV incidence trends in a hyperendemic population, we tested a cohort of 22,239 uninfected participants over 92,877 person- ...[more]
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Project description:BackgroundAd hoc assumptions about the unobserved infection event, which is known only to occur between the latest-negative and earliest-positive test dates, can lead to biased HIV incidence rate estimates. Using a G-imputation approach, we infer the infection dates from covariate data to estimate the HIV incidence rate in a hyper-endemic South African setting.MethodsA large demographic surveillance system has annually tested a cohort of HIV-uninfected participants living in the KwaZulu-Natal province. Using this data, we estimated a cumulative baseline hazard function and the effects of time-dependent covariates on the interval censored infection dates. For each HIV-positive participant in the cohort, we derived a cumulative distribution function and sampled multiple infection dates conditional on the unique covariate values. We right censored the data at the imputed dates, calculated the annual HIV incidence rate per 100 person-years, and used Rubin's rules to obtain the 95% confidence intervals.ResultsA total of 20,011 uninfected individuals with a repeat HIV test participated in the incidence cohort between 2005 and 2018. We observed 2,603 infections per 58,769 person-years of follow-up among women and 845 infections per 41,178 person-years of follow-up among men. Conditional on age and circumcision status (men only), the female HIV incidence rate declined by 25%, from 5.0 to 3.7 infections per 100 person-years between 2014 and 2018. During this period, the HIV incidence rate among men declined from 2.1 to 1.1 infections per 100 person-years-a reduction of 49%. We observed similar reductions in male and female HIV incidence conditional on condom-use, marital status, urban residential status, migration history, and the HIV prevalence in the surrounding community.ConclusionWe have followed participants in one of the world's largest and longest running HIV cohorts to estimate long-term trends in the population-wide incidence of infection. Using a G-imputation approach, we present further evidence for HIV incidence rate declines in this hyper-endemic South African setting.
| S-EPMC7409400 | biostudies-literature
Project description:IntroductionMen who have sex with men (MSM) and transgender women (TGW) are at increased risk for acquiring HIV, but there are limited HIV incidence data for these key populations in Africa. Understanding HIV prevalence and incidence provides important context for designing HIV prevention strategies, including pre-exposure prophylaxis (PrEP) programmes. We describe HIV prevalence, awareness of HIV infection, HIV incidence and associated factors for a cohort of MSM and TGW in Cape Town and Port Elizabeth, South Africa.MethodsFrom 2015 to 2016, MSM and TGW in Cape Town and Port Elizabeth were enrolled and prospectively followed for 12 months, receiving a comprehensive package of HIV prevention services. HIV testing was conducted at baseline and at follow-up visits (targeted for three, six and twelve months). All HIV-negative PrEP-eligible participants were offered PrEP enrolment during the first four months of study participation. We determined HIV prevalence among participants at baseline, and incidence by repeat screening of initially HIV-negative participants with HIV tests at three, six and twelve months.ResultsAmong 292 participants enrolled, HIV prevalence was high (43%; 95% CI: 38 to 49) and awareness of HIV status was low (50%). The 167 HIV-negative participants who were followed prospectively for 144.7 person-years; nine incident HIV infections were documented. Overall annual incidence was 6.2% (CI: 2.8 to 11.8) and did not differ by city. Annual HIV incidence was significantly higher for younger (18 to 19 years) MSM and TGW (MSM: 21.8% (CI: 1.2 to 100); TGW: 31.0 (CI: 3.7, 111.2)). About half of participants started PrEP during the study; the annual incidence of HIV among 82 (49%) PrEP starters was 3.6% (CI: 0.4, 13.1) and among those who did not start PrEP was 7.8% (CI: 3.1, 16.1).ConclusionsHIV incidence was high among MSM and TGW in the context of receiving a comprehensive package of prevention interventions and offering of PrEP. PrEP uptake was high; the observed incidence of HIV in those who started PrEP was about half the incidence of HIV in those who did not. Future implementation-oriented studies should focus on decisions to start and continue PrEP for those at highest risk, including young MSM.
| S-EPMC7527763 | biostudies-literature
Project description:BACKGROUND:Voluntary medical male circumcision has been promoted in high HIV prevalence settings to prevent HIV acquisition in males. However, the uptake of circumcision in many sub-Saharan African settings remains low. While many studies have measured circumcision prevalence, understanding circumcision incidence and its predictors is vital to achieving ambitious circumcision prevalence targets. SETTING:Rural KwaZulu-Natal, South Africa. METHODS:We measured circumcision incidence over the period 2009-2014 in a longitudinal population-based cohort with high HIV prevalence and low circumcision prevalence. Multivariable survival models with Weibull distributions were used to assess socio-demographic, behavioral and biological predictors of circumcision incidence. RESULTS:Between 2009 and 2014, circumcision prevalence among males 15-49 years in the cohort increased from 3% to 24%. Among 6,203 males 15-49 years, 873 new circumcisions occurred over 13,678 person-years (incidence rate: 6.4/100 person-years, 95% CI 6.0-6.8). Circumcision incidence was substantially higher amongst young males: 15-19 year olds were twice as likely to circumcise as older males. In the survival model, shorter household distance to the nearest healthcare facility, knowledge of HIV status and biological HIV-negative status were associated with an increased likelihood of circumcision incidence. CONCLUSIONS:Circumcision prevalence among males in rural KwaZulu-Natal remains well below South Africa's national 80% coverage target across age groups. In this population, distance to the nearest healthcare facility and knowledge of HIV status were important independent predictors of circumcision incidence. Mobile circumcision clinics and innovative HIV testing services may be important tools to help achieve circumcision targets.
| S-EPMC6300268 | biostudies-literature
Project description:In sub-Saharan Africa, high HIV incidence rates in adolescent girls and young women (AGYW) persist despite extensive HIV prevention efforts. A prospective cohort of 2,710 HIV-negative AGYW (15-24 years) in KwaZulu-Natal, South Africa were interviewed at baseline and followed-up approximately 18 months later (2014-2017). Associations between HIV seroconversion and socio-demographic and behavioural variables measured at baseline and follow-up were examined using Cox regression and a proximate determinants framework. Inter-relationships between determinants were measured using logistic regression. Separate models were built for 15-19 and 20-24-year-olds. Weighted HIV incidence was 3.92 per 100 person-years (95% confidence interval: 3.27-4.69; 163 seroconversions over 4,016 person-years). Among 15-19-year-olds, absence of family support (adjusted hazards ratio (aHR): 3.82 (1.89-7.72)), having a circumcised partner (aHR: 0.5 (0.27-0.94)) or one who was HIV-positive and not on antiretroviral therapy (ART) (aHR: 6.21 (2.56-15.06)) were associated with HIV incidence. Those reporting an absence of family support were also more likely to report >1 partner during follow-up (odds ratio (OR): 2.7(1.11-6.57)). Among 20-24-year-olds, failure to complete secondary school (aHR: 1.89 (1.11-3.21)), inconsistent condom use (aHR: 3.01 (1.14-7.96)) and reporting partner(s) who were HIV-positive and not on ART (aHR: 7.75 (3.06-19.66)) were associated with HIV incidence. Failure to complete secondary school among 20-24-year-olds was associated with inconsistent condom use (OR: 1.82 (1.20-2.77)) and reporting an HIV-positive partner not on ART (OR: 3.53(1.59-7.82)) or an uncircumcised partner (OR: 1.39 (1.08-1.82). Absence of family support and incomplete schooling are associated with risky sexual behaviours and HIV acquisition in AGYW. In addition, partner-level prevention-condom use, medical circumcision, and viral suppression-continue to play an important role in reducing HIV risk in AGYW. These findings support the use of combination HIV prevention programs that consider structural as well as biological and behavioural HIV risk factors in their design.
| S-EPMC9770356 | biostudies-literature
Project description:BackgroundThrough a multisectoral approach, the DREAMS Partnership aimed to reduce HIV incidence among adolescent girls and young women (AGYW) by 40% over 2 years in high-burden districts across sub-Saharan Africa. DREAMS promotes a combination package of evidence-based interventions to reduce individual, family, partner, and community-based drivers of young women's heightened HIV risk. We evaluated the impact of DREAMS on HIV incidence among AGYW and young men in 2 settings.Methods and findingsWe directly estimated HIV incidence rates among open population-based cohorts participating in demographic and HIV serological surveys from 2006 to 2018 annually in uMkhanyakude (KwaZulu-Natal, South Africa) and over 6 rounds from 2010 to 2019 in Gem (Siaya, Kenya). We compared HIV incidence among AGYW aged 15 to 24 years before DREAMS and up to 3 years after DREAMS implementation began in 2016. We investigated the timing of any change in HIV incidence and whether the rate of any change accelerated during DREAMS implementation. Comparable analyses were also conducted for young men (20 to 29/34 years). In uMkhanyakude, between 5,000 and 6,000 AGYW were eligible for the serological survey each year, an average of 85% were contacted, and consent rates varied from 37% to 67%. During 26,395 person-years (py), HIV incidence was lower during DREAMS implementation (2016 to 2018) than in the previous 5-year period among 15- to 19-year-old females (4.5 new infections per 100 py as compared with 2.8; age-adjusted rate ratio (aRR) = 0.62, 95% confidence interval [CI] 0.48 to 0.82), and lower among 20- to 24-year-olds (7.1/100 py as compared with 5.8; aRR = 0.82, 95% CI 0.65 to 1.04). Declines preceded DREAMS introduction, beginning from 2012 to 2013 among the younger and 2014 for the older women, with no evidence of more rapid decline during DREAMS implementation. In Gem, between 8,515 and 11,428 AGYW were eligible each survey round, an average of 34% were contacted and offered an HIV test, and consent rates ranged from 84% to 99%. During 10,382 py, declines in HIV incidence among 15- to 19-year-olds began before DREAMS and did not change after DREAMS introduction. Among 20- to 24-year-olds in Gem, HIV incidence estimates were lower during DREAMS implementation (0.64/100 py) compared with the pre-DREAMS period (0.94/100 py), with no statistical evidence of a decline (aRR = 0.69, 95% CI 0.53 to 2.18). Among young men, declines in HIV incidence were greater than those observed among AGYW and also began prior to DREAMS investments. Study limitations include low study power in Kenya and the introduction of other interventions such as universal treatment for HIV during the study period.ConclusionsSubstantial declines in HIV incidence among AGYW were observed, but most began before DREAMS introduction and did not accelerate in the first 3 years of DREAMS implementation. Like the declines observed among young men, they are likely driven by earlier and ongoing investments in HIV testing and treatment. Longer-term implementation and evaluation are needed to assess the impact of such a complex HIV prevention intervention and to help accelerate reductions in HIV incidence among young women.
| S-EPMC8880902 | biostudies-literature
Project description:IntroductionMen who have sex with men (MSM) and transgender women (TGW) experience high incidence and prevalence of sexually transmitted infections (STI), and data are needed to understand risk factors for STIs in these populations. The Sibanye Health Project was conducted in Cape Town and Port Elizabeth, South Africa from 2015 to 2016 to develop and test a package of HIV prevention interventions for MSM and TGW. We describe the incidence, prevalence and symptoms of Chlamydia trachomatis (CT), Neisseria gonorrhea (NG) and syphilis observed during the study.MethodsParticipants completed HIV testing at baseline. All participants who were HIV negative were followed prospectively. Additionally, a sample of participants identified as living with HIV at baseline was selected to be followed prospectively so that the prospective cohort was approximately 20% HIV positive; the remaining participants identified as HIV positive at baseline were not followed prospectively. Prospective participants were followed for 12 months and returned for clinic-based STI/HIV testing and assessment of STI symptoms at months 6 and 12. Additional HIV/STI testing visits could be scheduled at participant request.ResultsFollowing consent, a total of 292 participants attended a baseline visit (mean age = 26 years), and 201 were enrolled for the 12-month prospective study. Acceptance of screening for syphilis and urethral NG/CT was near universal, though acceptance of screening for rectal NG/CT was lower (194/292; 66%). Prevalence of urethral CT and NG at baseline was 10% (29/289) and 3% (8/288) respectively; incidence of urethral CT and NG was 12.8/100 person-years (PY) and 7.1/100 PY respectively. Prevalence of rectal CT and NG at baseline was 25% (47/189) and 16% (30/189) respectively; incidence of rectal CT and NG was 33.4/100 PY and 26.8/100 PY respectively. Prevalence of syphilis at baseline was 17% (45/258) and incidence was 8.2/100 PY. 91%, 95% and 97% of diagnosed rectal NG/CT, urethral NG/CT and syphilis infections, respectively, were clinically asymptomatic.ConclusionsPrevalence and incidence of urethral and rectal STIs were high among these South African MSM and TGW, and were similar to rates in other settings in the world. Clinical symptoms from these infections were rare, highlighting limitations of syndromic surveillance and suggesting the need for presumptive testing and/or treatment to address the STI epidemic among MSM/TGW in South Africa.
| S-EPMC7527766 | biostudies-literature
Project description:There has been very little prospective research on rape perpetration among men. This paper describes the incidence and risk factors for new rape and attempted rape events among young South African men in an HIV prevention trial.We followed 1,147 men aged 15-26 years who enrolled into a cluster randomised controlled trial to evaluate the HIV prevention behavioural intervention Stepping Stones. Incidence rate ratios for factors associated with incident rape were derived from Poisson models.The young men reported 217 incident rapes (completed or attempted) of a girl or woman over 1,914 person years of follow up, yielding a rape incidence of 11.2 per 100 person years. Overall 24.9% of men had previously raped at baseline, and 18.9% did so during the follow up. Among the latter, 61.3% raped for the first time, and 38.7% re-offended. Multivariable Poisson modelling showed a higher incidence of rape perpetration among men who had ever used drugs (IRR 1.86 95%CI 1.39, 2.49), had eight or more lifetime partners (IRR 1.48 95% CI 1.09, 2.01), had been physically violent toward a female partner (IRR 1.50 95%CI 1.11, 2.03) and had disclosed rape perpetration at baseline (IRR 1.45 95%CI 1.07, 1.97). A lower incidence was found among those with greater resistance to peer pressure (IRR 0.85 95%CI 0.74, 0.97).The findings highlight the importance of male gender socialisation and addressing delinquent youth sub-cultures in rape prevention. Prevention requires change in hegemonic masculinity, with its emphasis on gender hierarchy, exaggerated performance of heterosexuality and control of women. Interventions are needed to address male socialisation with delinquent peers, by reducing exposure to childhood trauma and strengthening opportunities for gainful employment (in work or recreation).
| S-EPMC3365003 | biostudies-other
Project description:BACKGROUND:Based on ethnographic investigations and mathematical models, older sexual partners are often considered a major risk factor for HIV for young women in sub-Saharan Africa. Numerous public health campaigns have been conducted to discourage young women from relationships with older men. However, longitudinal evidence relating sex partner age disparity to HIV acquisition in women is limited. METHODS:Using data from a population-based open cohort in rural KwaZulu-Natal, South Africa, we studied 15- to 29-year-old women who were HIV seronegative at first interview between January 2003 and June 2012 (n = 2444). We conducted proportional hazards analysis to establish whether the age disparity of women's most recent sexual partner, updated at each surveillance round, was associated with subsequent HIV acquisition. RESULTS:A total of 458 HIV seroconversions occurred over 5913 person-years of follow-up (incidence rate: 7.75 per 100 person-years). Age disparate relationships were common in this cohort; 37.7% of women reported a partner 5 or more years older than themselves. The age disparity of women's partners was not associated with HIV acquisition when measured either continuously [hazard ratio (HR) for 1-year increase in partner's age: 1.00, 95% confidence interval (CI): 0.97 to 1.03] or categorically (man ?5 years older: HR, 0.98; 95% CI: 0.81 to 1.20; man ?10 years older: HR, 0.98; 95% CI: 0.67 to 1.43). These results were robust to adjustment for known sociodemographic and behavioral HIV risk factors and did not vary significantly by women's age, marital status, education attainment, or household wealth. CONCLUSIONS:HIV incidence in young women was very high in this rural community in KwaZulu-Natal. Partner age disparity did not predict HIV acquistion. Campaigns to reduce age-disparate sexual relationships may not be a cost-effective use of HIV prevention resources in this setting.
| S-EPMC4097949 | biostudies-literature
Project description:BackgroundHIV prevention trials are increasingly being conducted in sub-Saharan Africa. Women at risk for HIV are also at risk of pregnancy. To maximize safety, women agree to avoid pregnancy during trials, yet pregnancies occur. Using data from the HVTN 503/"Phambili" vaccine trial, we report pregnancy incidence during and after the vaccination period and identify factors, measured at screening, associated with incident pregnancy.MethodsTo enrol in the trial, women agreed and were supported to avoid pregnancy until 1 month after their third and final vaccination ("vaccination period"), corresponding to the first 7 months of follow-up. Unsterilized women, pooled across study arms, were analyzed. Poisson regression compared pregnancy rates during and after the vaccination period. Cox proportional hazards regression identified associations with first pregnancy.ResultsAmong 352 women (median age 23 yrs; median follow-up 1.5 yrs), pregnancy incidence was 9.6/100 women-years overall and 6.8/100 w-yrs and 11.3/100 w-yrs during and after the vaccination period, respectively [Rate Ratio = 0.60 (0.32-1.14), p = 0.10]. In multivariable analysis, pregnancy was reduced among women who: enrolled at sites providing contraception on-site [HR = 0.43, 95% CI (0.22-0.86)]; entered the trial as injectable contraceptive users [HR = 0.37 (0.21-0.67)] or as consistent condom users (trend) [HR = 0.54 (0.28-1.04)]. Compared with women with a single partner of HIV-unknown status, pregnancy rates were increased among women with: a single partner whose status was HIV-negative [HR = 2.34(1.16-4.73)] and; 2 partners both of HIV-unknown status [HR = 4.42(1.59-12.29)]. Women with 2 more of these risk factors: marijuana use, heavy drinking, or use of either during sex, had increased pregnancy incidence [HR = 2.66 (1.24-5.72)].ConclusionsIt is possible to screen South African women for pregnancy risk at trial entry. Providing injectable contraception for free on-site and supporting consistent condom use may reduce incident pregnancy. Screening should determine the substance use, partnering, and HIV status of both members of the couple for both pregnancy and HIV prevention.Trial registrationSA National Health Research Database DOH-27-0207-1539; Clinicaltrials.gov NCT00413725.
| S-EPMC3331975 | biostudies-literature
Project description:BackgroundOral pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, but data are limited on HIV incidence among PrEP users in generalized epidemic settings, particularly outside of selected risk groups. We performed a population-based PrEP study in rural Kenya and Uganda and sought to evaluate both changes in HIV incidence and clinical and virologic outcomes following seroconversion on PrEP.Methods and findingsDuring population-level HIV testing of individuals ≥15 years in 16 communities in the Sustainable East Africa Research in Community Health (SEARCH) study (NCT01864603), we offered universal access to PrEP with enhanced counseling for persons at elevated HIV risk (based on serodifferent partnership, machine learning-based risk score, or self-identified HIV risk). We offered rapid or same-day PrEP initiation and flexible service delivery with follow-up visits at facilities or community-based sites at 4, 12, and every 12 weeks up to week 144. Among participants with incident HIV infection after PrEP initiation, we offered same-day antiretroviral therapy (ART) initiation and analyzed HIV RNA, tenofovir hair concentrations, drug resistance, and viral suppression (<1,000 c/ml based on available assays) after ART start. Using Poisson regression with cluster-robust standard errors, we compared HIV incidence among PrEP initiators to incidence among propensity score-matched recent historical controls (from the year before PrEP availability) in 8 of the 16 communities, adjusted for risk group. Among 74,541 individuals who tested negative for HIV, 15,632/74,541 (21%) were assessed to be at elevated HIV risk; 5,447/15,632 (35%) initiated PrEP (49% female; 29% 15-24 years; 19% in serodifferent partnerships), of whom 79% engaged in ≥1 follow-up visit and 61% self-reported PrEP adherence at ≥1 visit. Over 7,150 person-years of follow-up, HIV incidence was 0.35 per 100 person-years (95% confidence interval [CI] 0.22-0.49) among PrEP initiators. Among matched controls, HIV incidence was 0.92 per 100 person-years (95% CI 0.49-1.41), corresponding to 74% lower incidence among PrEP initiators compared to matched controls (adjusted incidence rate ratio [aIRR] 0.26, 95% CI 0.09-0.75; p = 0.013). Among women, HIV incidence was 76% lower among PrEP initiators versus matched controls (aIRR 0.24, 95% CI 0.07-0.79; p = 0.019); among men, HIV incidence was 40% lower, but not significantly so (aIRR 0.60, 95% CI 0.12-3.05; p = 0.54). Of 25 participants with incident HIV infection (68% women), 7/25 (28%) reported taking PrEP ≤30 days before HIV diagnosis, and 24/25 (96%) started ART. Of those with repeat HIV RNA after ART start, 18/19 (95%) had <1,000 c/ml. One participant with viral non-suppression was found to have transmitted viral resistance, as well as emtricitabine resistance possibly related to PrEP use. Limitations include the lack of contemporaneous controls to assess HIV incidence without PrEP and that plasma samples were not archived to assess for baseline acute infection.ConclusionsPopulation-level offer of PrEP with rapid start and flexible service delivery was associated with 74% lower HIV incidence among PrEP initiators compared to matched recent controls prior to PrEP availability. HIV infections were significantly lower among women who started PrEP. Universal HIV testing with linkage to treatment and prevention, including PrEP, is a promising approach to accelerate reductions in new infections in generalized epidemic settings.Trial registrationClinicalTrials.gov NCT01864603.
| S-EPMC7872279 | biostudies-literature