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. 2022 Dec 15;91(5):439-448.
doi: 10.1097/QAI.0000000000003097. Epub 2022 Sep 20.

The Prevalence, Incidence, and Risk Factors for HIV Among Female Sex Workers-A Cohort Being Prepared for a Phase IIb HIV Vaccine Trial in Dar es Salaam, Tanzania

Diana Faini  1   2 , Frank Msafiri  3   4 , Patricia Munseri  5 , Muhammad Bakari  5 , Eligius Lyamuya  3 , Eric Sandström  6 , Gunnel Biberfeld  2 , Charlotta Nilsson  4 , Claudia Hanson  2   7 , Said Aboud  3
Affiliations

The Prevalence, Incidence, and Risk Factors for HIV Among Female Sex Workers-A Cohort Being Prepared for a Phase IIb HIV Vaccine Trial in Dar es Salaam, Tanzania

Diana Faini et al. J Acquir Immune Defic Syndr. .

Abstract

Background: A cohort of female sex workers (FSWs) was established to determine HIV prevalence and incidence, and associated factors in preparation for a phase IIb HIV vaccine and pre-exposure prophylaxis trial (PrEPVacc).

Setting: A cohort of FSWs in Dar es Salaam, Tanzania.

Methods: FSWs aged 18-45 years were recruited using a respondent-driven sampling method. Social demographic data, HIV risk behavioral assessments, and blood samples for testing of HIV, syphilis, hepatitis B (HBV), and hepatitis C (HCV) infections were collected at baseline and then at 3, 6, 9, and 12 months. Poisson regressions were used to estimate the prevalence ratios for factors associated with HIV prevalence and to estimate the 12-month HIV incidence rate.

Results: Between October and December 2018, a total of 773 FSWs were screened for eligibility and 700 were enrolled. The baseline prevalence of HIV, syphilis, HBV, and HCV was 7.6%, 1.2%, 1.7%, and 1.0%, respectively. HIV prevalence was associated with older age, using illicit drugs, and being infected with syphilis, HBV, or HCV. Attendance at 12 months was 80% (562/700). Twenty-one FSWs seroconverted during follow-up, giving a 12-month HIV incidence rate of 3.45 per 100 person-years at risk (95% CI; 2.25-5.28/100 person-years at risk). The HIV incidence rate was higher among FSWs aged 18-24 years, FSWs who used drugs, and those diagnosed with syphilis, HBV, or HCV.

Conclusion: The high HIV incidence rate and retention rate among FSWs enrolled into the cohort demonstrate that this population is suitable for participation in HIV prevention trials.

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Conflict of interest statement

The authors have no funding or conflicts of interest to disclose.

Figures

FIGURE 1.
FIGURE 1.
Screening, enrolment, and follow-up of female sex workers in the PrEPVacc registration cohort, Dar es Salaam, Tanzania.
FIGURE 2.
FIGURE 2.
Cumulative hazard curves showing HIV incidence among female sex workers enrolled in the PrEPVacc cohort, Dar es Salaam, by social demographic and behavioral characteristics.
See this image and copyright information in PMC

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