Prevalence, incidence, and distribution of human papillomavirus types in female sex workers in Kenya
Kristen M. Sweet, Claire Bosire, Busola Sanusi, Carly J. Sherrod, Jessie Kwatampora, Wairimu Waweru, Nelly Mugo, Joshua Kimani, Jie Ting, Jennifer Clark, Dirk P. Dittmer, Jennifer S. Smith
Abstract
Female sex workers (FSWs) have a notably high risk of acquiring human papillomavirus (HPV) infections. Relatively few studies address the type-specific prevalence and incidence of HPV among FSWs in sub-Saharan Africa. FSWs (n = 348) attending the Korogocho clinic in Nairobi, Kenya participated from August 2009 to March 2011. HPV DNA was detected using the SPF10-LiPA25 PCR assay. Baseline prevalence of HPV infection and cervical dysplasia were calculated, stratified by HIV-serostatus. Incidence rate (IR) of infection was calculated as number of new infections from baseline over person-months among 160 HPV-negative participants with complete 12-month follow-up. Baseline HPV prevalence was 23.6% for any HPV and 20.4% for high-risk HPV (hrHPV) types. Most prevalent types were HPV52 (10.1%), HPV35 (2.3%), and HPV51 (2.3%). A quarter (24%) of participants were HIV-positive. HPV prevalence was higher in HIV-positive (32.1%) than HIV-negative (20.8%) participants. hrHPV prevalence was higher in HIV-positive (27.4%) than HIV-negative (18.2%) women. During follow-up, HPV IR was 31.4 (95% CI: 23.8–41.5) for any HPV and 24.2 (95% CI: 17.9–32.8) for hrHPV types. HPV52 had the highest IR (6.0; 95% CI: 6.5–10.3). Overall HPV and hrHPV prevalence were lower than expected, but both prevalence and incidence were higher in HIV-positive than in HIV-negative women.