Declines in HIV prevalence in female sex workers accessing an HIV treatment and prevention programme in Nairobi, Kenya over a 10-year period.

Abstract

Empirical time trends in HIV prevalence in female sex workers (FSWs) are helpful to understand the evolving HIV epidemic, and to monitor the scale-up, coverage, and impact of ongoing HIV prevention and treatment programmes. Serial HIV prevalence study. We analyzed time trends in HIV prevalence in FSWs accessing services at seven Sex Worker Outreach Programme (SWOP) clinics in Nairobi from 2008 to 2017 (N = 33 560). The Mantel--Haenszel test for trend and independent samples Kruskal--Wallis test were used to analyze categorical and continuous variables, respectively. Multivariable binomial regression was used to estimate prevalence ratios/year, adjusting for several covariates. HIV prevalence decreased over time in all age groups. This was particularly evident among FSWs less than 25 years of age; HIV was 17.5% in 2008-2009, decreasing to 12.2% in 2010-2011, 8.3% in 2012-2013, 7.3% in 2014-2015, and 4.8% in 2016-2017 (P < 0.0001). Over time, FSWs reported increased condom use, particularly with regular partners, more frequent prior HIV testing, and were less likely to report a history of vaginal discharge (P < 0.0001). In adjusted analyses compared with 2008, HIV prevalence decreased in 2011 (aPR 0.64; 95% CI: 0.46-0.90), 2012 (aPR 0.58; 95% CI: 0.41-0.81), 2013 (aPR 0.53; 95% CI: 0.38-0.73), 2014 (aPR 0.48; 95% CI: 0.34-0.67), 2015 (aPR 0.50; 95% CI: 0.35-0.70), 2016 (aPR 0.40; 95% CI: 0.28-0.57), and 2017 (aPR 0.33; 95% CI: 0.22-0.50). HIV prevalence has decreased among FSW accessing SWOP in Nairobi, Kenya. This decline is consistent with the scale-up of HIV prevention and treatment efforts, both in FSWs and in the general population.