Indeterminate and discrepant rapid HIV test results in couples' HIV testing and counselling centres in Africa

<p>Abstract</p> <p>Background</p> <p>Many HIV voluntary testing and counselling centres in Africa use rapid antibody tests, in parallel or in sequence, to establish same-day HIV status. The interpretation of indeterminate or discrepant results between different rapid tests on one sample poses a challenge. We investigated the use of an algorithm using three serial rapid HIV tests in cohabiting couples to resolve unclear serostatuses.</p> <p>Methods</p> <p>Heterosexual couples visited the Rwanda Zambia HIV Research Group testing centres in Kigali, Rwanda, and Lusaka, Zambia, to assess HIV infection status. Individuals with unclear HIV rapid antibody test results (indeterminate) or discrepant results were asked to return for repeat testing to resolve HIV status. If either partner of a couple tested positive or indeterminate with the screening test, both partners were tested with a confirmatory test. Individuals with indeterminate or discrepant results were further tested with a tie-breaker and monthly retesting. HIV-RNA viral load was determined when HIV status was not resolved by follow-up rapid testing. Individuals were classified based on two of three initial tests as "Positive", "Negative" or "Other". Follow-up testing and/or HIV-RNA viral load testing determined them as "Infected", "Uninfected" or "Unresolved".</p> <p>Results</p> <p>Of 45,820 individuals tested as couples, 2.3% (4.1% of couples) had at least one discrepant or indeterminate rapid result. A total of 65% of those individuals had follow-up testing and of those individuals initially classified as "Negative" by three initial rapid tests, less than 1% were resolved as "Infected". In contrast, of those individuals with at least one discrepant or indeterminate result who were initially classified as "Positive", only 46% were resolved as "Infected", while the remainder was resolved as "Uninfected" (46%) or "Unresolved" (8%). A positive HIV serostatus of one of the partners was a strong predictor of infection in the other partner as 48% of individuals who resolved as "Infected" had an HIV-infected spouse.</p> <p>Conclusions</p> <p>In more than 45,000 individuals counselled and tested as couples, only 5% of individuals with indeterminate or discrepant rapid HIV test results were HIV infected. This represented only 0.1% of all individuals tested. Thus, algorithms using screening, confirmatory and tie-breaker rapid tests are reliable with two of three tests negative, but not when two of three tests are positive. False positive antibody tests may persist. HIV-positive partner serostatus should prompt repeat testing.</p

Factors associated with alcohol use before sex among HIV-negative female sex workers in Zambia

International audienceFemale sex workers (FSWs) are at high risk of HIV infection. Alcohol use prior to sex can compound this risk. We investigated the factors associated with having sex under the influence of alcohol among Zambian FSWs. Community health workers and peer FSWs recruited 331 HIV-negative FSWs in Lusaka and Ndola. In a cross-sectional survey, we asked FSWs how often they had sex under the influence of alcohol in the previous month and categorised responses as ‘always’ and ‘not always’. The adjusted odds ratios (AORs) of always having sex under the influence of alcohol were higher among FSWs who charged clients medium (AOR: 2.20, 95% confidence interval [CI]: 1.04–4.68) and low fees (AOR: 2.65, 95% CI: 1.26–5.60) for sex versus high fees; received 9–19 (AOR: 2.37, 95% CI: 1.15–4.91) and 20 or more clients per month (AOR: 3.06, 95% CI: 1.47–6.37) versus up to 8 clients per month; and never used condoms versus always used condoms with clients (AOR: 4.21, 95% CI: 1.53–11.55). FSWs who always used alcohol before sex appeared more likely to engage in riskier sex and charge clients lower fees. Interventions for financial empowerment and alcohol risk reduction should complement existing HIV prevention interventions for FSWs

Client-Initiated Violence Against Zambian Female Sex Workers: Prevalence and Associations With Behavior, Environment, and Sexual History

International audienceViolence against women is a known risk factor for HIV and affects female sex workers (FSW) in sub-Saharan Africa. Little is known about the magnitude and determinants of violence against FSW in Zambia, where HIV and gender-based violence prevalence are high. We conducted a cross-sectional study, using multivariable logistic regression, to determine the prevalence and correlates of client-initiated physical violence among 419 FSW in Lusaka and Ndola. The prevalence of client-initiated physical violence was 39%. The odds of violence were higher for FSW who: lived in Lusaka, recruited clients from the street, serviced clients in the clients’ homes, had a physically forced sexual debut, and had a higher client volume. Our results call for safer working spaces for FSW and violence prevention interventions for their male clients

Evolution of Condom Use Among a 5-Year Cohort of Female Sex Workers in Zambia

International audienceObserving sexual behaviour change over time could help develop behavioural HIV prevention interventions for female sex workers in Zambia, where these interventions are lacking. We investigated the evolution of consistent condom use among female sex workers and their clients and steady partners. Participants were recruited into an HIV incidence cohort from 2012 to 2017. At each visit, women received HIV counselling and testing, screening for sexually transmitted infections (STIs) and free condoms. Our outcome was reported consistent (100%) condom use in the previous month with steady partners, repeat clients, and non-repeat clients. Consistent condom use at baseline was highest with non-repeat clients (36%) followed by repeat clients (27%) and steady partners (17%). Consistent condom use between baseline and Month 42 increased by 35% with steady partners, 39% with repeat clients and 41% with non-repeat clients. Access to condoms, HIV/STI counselling and testing promoted positive sexual behaviour change

A couple-focused, integrated unplanned pregnancy and HIV prevention program in urban and rural Zambia

International audienceBackground: Zambia's total fertility rate (5 births per woman) and adult HIV prevalence (11.5%) are among the highest in the world, with heterosexual couples being the most affected group. Jointly counseling and testing couples for HIV has reduced up to 58% of new HIV infections in Zambian clinics. Married women using contraceptives in Zambia have a high (20%) unmet need for family planning and low (8.6%) uptake of cost-effective long-acting reversible contraceptives. We present an integrated counseling, testing, and family-planning program to prevent HIV and unplanned pregnancy in Zambia.Objective: The objective of this study was to integrate effective HIV prevention and family-planning services for Zambian couples.Study design: A 3 year program (2013-2016) progressively integrated the promotion and provision of couples' voluntary HIV counseling and testing and long-acting reversible contraceptives. The program was based in 55 urban and 215 rural government clinics across 33 districts. In the first year, a couples' family-planning counseling training program was developed and combined with existing couples HIV counseling training materials. To avoid congestion during routine clinic hours, joint counseling services were initially provided on weekends, while nurses were trained in intrauterine device and hormonal implant insertion and removal during weekday family-planning services. Demand was created through mutual referral between weekend and weekday programs and by clinic staff, community health workers, and satisfied family-planning clients. When the bulk of integrated service training was completed, the program transitioned services to routine weekday clinic hours, ensuring access to same-day services. Performance indicators included number of staff trained, clients served, integrated service referrals, HIV infections averted, and unplanned pregnancies averted.Results: A stepwise approach trained high-performing service providers to be trainers and used high-volume clinics for practicum training of the next generation. In total, 1201 (391 urban, 810 rural) counselors were trained and served 120,535 urban and 87,676 rural couples. In urban clinics, 236 nurses inserted 65,619 long-acting reversible contraceptives, while in rural clinics, 243 nurses inserted 35,703 implants and intrauterine devices. The program prevented an estimated 12,869 urban and 8279 rural adult HIV infections, and 98,626 unintended urban pregnancies. In the final year, the proportion of clients receiving joint counseling services on weekdays rose from 11% to 89%, with many referred from within clinics including HIV testing and treatment services (32%), outpatient department (31%), family planning (16%), and infant vaccination (15%). The largest group of clients requesting long-acting reversible contraceptives (45%) did so after joint fertility goal-based counseling, confirming the high impact of this couple-focused demand creation approach. Remaining family-planning clients responded to referrals from clinic nurses (34%), satisfied implant/intrauterine device users (13%), or community health workers (8%).Conclusion: Integrated HIV and unplanned pregnancy prevention can be implemented in low-resource public sector facilities. Combination services offered to couples mutually leverage HIV prevention and unplanned pregnancy prevention. The addition of long-acting reversible contraceptives is an important complement to the method mix available in government clinics. Demand creation in the clinic and in the community must be coordinated with a growing supply of well-trained providers

Measles immunity gap among reproductive-age women participating in a simulated HIV vaccine efficacy trial in Zambia

Measles is a vaccine-preventable viral disease whose vaccination coverage remains low in Zambia, where the target group for vaccination is children aged 9 to 18 months. In addition to inadequate measles vaccination coverage among children, few studies address potential resultant immunity gaps among adults. We analyzed data from a simulated HIV vaccine efficacy trial (SiVET) conducted from 2015–2017 among adult Zambian women of childbearing age to determine measles antibody seroprevalence before and after vaccination with the measles, mumps and rubella (MMR) vaccine. We used MMR vaccine as a substitute for an experimental HIV vaccine as part of a simulation exercise to prepare for an HIV vaccine efficacy trial. We found that 75% of women had measles antibodies prior to receiving MMR, which increased to 98% after vaccination. In contrast, mumps and rubella antibody prevalence was high before (93% and 97%, respectively) and after (99% and 100%, respectively) vaccination. The low baseline measles seropositivity suggests an immunity gap among women of childbearing age. We recommend that measles vaccination programs target women of childbearing age, who can pass antibodies on to neonates. Moreover, administering the MMR vaccine to clinical trial candidates could prevent measles, mumps or rubella-related adverse events during actual trials

Loss to follow-up among female sex workers in Zambia: findings from a five-year HIV-incidence cohort

HIV-incidence studies are used to identify at-risk populations for HIV-prevention trials and interventions, but loss to follow-up (LTFU) can bias results if participants who remain differ from those who drop out. We investigated the incidence of and factors associated with LTFU among Zambian female sex workers (FSWs) in an HIV-incidence cohort from 2012 to 2017. Enrolled participants returned at month one, month three and quarterly&nbsp; thereafter. FSWs were considered LTFU if they missed six consecutive months, or if their last visit was six months before the study end date. Of 420 FSWs, 139 (33%) were LTFU at a rate of 15.7 per 100 person years. In multivariable analysis, LTFU was greater for FSWs who never used alcohol, began sex work above the age of consent, and had a lower volume of new clients. Our study appeared to retain FSWs in most need of HIV-prevention services offered at follow-up. Keywords: alcohol, incidence studies, prevention trials, risk behaviou

Cost-effectiveness of couples’ voluntary HIV counselling and testing in six African countries: a modelling study guided by an HIV prevention cascade framework

Introduction: Couples’ voluntary HIV counselling and testing (CVCT) is a high-impact HIV prevention intervention in Rwanda and Zambia. Our objective was to model the cost-per-HIV infection averted by CVCT in six African countries guided by an HIV prevention cascade framework. The HIV prevention cascade as yet to be applied to evaluating CVCT effectiveness or cost-effectiveness. Methods: We defined a priority population for CVCT in Africa as heterosexual adults in stable couples. Based on our previous experience nationalizing CVCT in Rwanda and scaling-up CVCT in 73 clinics in Zambia, we estimated HIV prevention cascade domains of motivation for use, access and effectiveness of CVCT as model parameters. Costs-per-couple tested were also estimated based on our previous studies. We used these parameters as well as country-specific inputs to model the impact of CVCT over a five-year time horizon in a previously developed and tested deterministic compartmental model. We consider six countries across Africa with varied HIV epidemics (South Africa, Zimbabwe, Kenya, Tanzania, Ivory Coast and Sierra Leone). Outcomes of interest were the proportion of HIV infections averted by CVCT, nationwide CVCT implementation costs and costs-per-HIV infection averted by CVCT. We applied 3%/year discounting to costs and outcomes. Univariate and Monte Carlo multivariate sensitivity analyses were conducted. Results: We estimated that CVCT could avert between 54% (Sierra Leone) and 62% (South Africa) of adult HIV infections. Average costs-per-HIV infection averted were lowest in Zimbabwe ($550) and highest in South Africa ($1272). Nationwide implementations would cost between 7% (Kenya) and 21% (Ivory Coast) of a country’s President’s Emergency Plan for AIDS Relief (PEPFAR) budget over five years. In sensitivity analyses, model outputs were most sensitive to estimates of cost-per-couple tested; the proportion of adults in heterosexual couples and HIV prevention cascade domains of CVCT motivation and access. Conclusions: Our model indicates that nationalized CVCT could prevent over half of adult HIV infections for 7% to 21% of the modelled countries’ five-year PEPFAR budgets. While other studies have indicated that CVCT motivation is high given locally relevant promotional and educational efforts, without required indicators, targets and dedicated budgets, access remains low

HIV testing and counselling couples together for affordable HIV prevention in Africa

Background: The impact and cost-effectiveness of couples’ voluntary HIV counselling and testing (CVCT) has not been quantified in real-world settings. We quantify cost-per-HIV-infection averted by CVCT in Zambia from the donor’s perspective. Methods: From 2010 to 2016, CVCT was established in 73 Zambian government clinics. The cost-per-HIV-infection averted (CHIA) of CVCT was calculated using observed expenditures and effectiveness over longitudinal follow-up. These observed measures parameterized hypothetical 5-year nationwide implementations of: ‘CVCT’; ‘treatment-as-prevention (TasP) for discordant couples’ identified by CVCT; and ‘population TasP’ for all HIV+ cohabiting persons identified by individual testing. Results: In all, 207 428 couples were tested (US $52/couple). Among discordant couples in which HIV+ partners self-reported antiretroviral therapy (ART), HIV incidence was 8.5/100 person-years before and 1.8/100 person-years after CVCT (79$659 CHIA. In nationwide implementation models, CVCT would prevent 17 times the number of infections vs ‘TasP for discordant couples’ at 86% of the cost, and nine times the infections vs ‘population TasP’ at 28% of the cost. Conclusions: CVCT is a cost-effective, feasible prevention strategy in Zambia. We demonstrate the novel, added effectiveness of providing CVCT to ART users, for whom ART use alone only partially mitigated transmission risk. Our results indicate a major policy shift (supporting development of CVCT indicators, budgets and targets) and have clinical implications (suggesting promotion of CVCT in ART clinics as a high-impact prevention strategy)