HIV Postexposure Prophylaxis in an Urban Population of Female Sex Workers in Nairobi, Kenya

Izulla, Preston MBChB*; McKinnon, Lyle R. PhD*,†; Munyao, Julius*; Karanja, Sarah BA, MS*; Koima, Winnie BScN*; Parmeres, Joshua BSN*; Kamuti, Solomon BSN*; Kioko, Rosalia BSN*; Nagelkerke, Nico PhD‡,§,‖; Gakii, Gloria BA, MS*; Wachihi, Charles MBChB*; Muraguri, Nicholas MBChB, MPH; Musyoki, Helgar BA, MPH; Gelmon, Lawrence MD, MPH*,‡; Kaul, Rupert MD, PhD*,†; Kimani, Joshua MBChB, MPH*,‡

JAIDS Journal of Acquired Immune Deficiency Syndromes:
doi: 10.1097/QAI.0b013e318278ba1b
Epidemiology and Prevention

Objectives: To assess biological and behavioral factors in HIV-uninfected female sex workers (FSWs) accessing postexposure prophylaxis (PEP) and to characterize the circumstances preceding PEP, time to access, and adherence.

Methods: Participants were HIV-uninfected FSWs enrolled in an HIV care and prevention program in Nairobi, Kenya. Those accessing PEP between 2009 and 2010 were enrolled and compared with controls. Multiple logistic regression models were used to compare PEP-related biological and behavioral parameters.

Results: PEP users (n = 326) had been involved in sex work for a shorter duration than nonusers [n = 2570; 3.3 vs. 5.1 yrs, AOR: 0.92, 95% confidence interval (CI): 0.89 to 0.95] and were less likely to report a regular partner (54.9% vs. 72.5%, AOR: 0.52, 0.39 to 0.68). PEP use was associated with gonorrhea infection (6.9% vs. 2.6%, AOR: 2.37, 95% CI: 1.34 to 4.21) and alcohol use (84.3% vs. 76.1%, AOR: 1.58, 95% CI: 1.09 to 2.31), but with increased condom use (85.1% vs. 68.2%, AOR 1.80, 95% CI: 1.38-2.35) and a history of prior HIV testing (89.2 vs. 76.2%, AOR: 2.22, 95% CI: 1.45 to 3.40). Reasons for PEP access centered on issues of client mistrust. The median time from exposure to PEP was 18 hours, with an estimated adherence of 49%. Precise PEP efficacy could not be calculated, but HIV incidence was 0.6% in users (2/326) compared with 2.1% (30/1417) in nonusers (Cox regression P = 0.35).

Conclusions: “PEP services were accessed by 10% of FSWs during the study period and were not implicated in any incident HIV cases.” Users had indicators of increased sexual risk and higher health care literacy. Increasing PEP access and compliance in FSWs may be an important HIV prevention strategy.

Author Information

*Department of Medical Microbiology, Kenya AIDS Control Project, University of Nairobi, Nairobi, Kenya

Department of Medicine, University of Toronto, Toronto, Ontario, Canada

Department of Medical Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada

§Department of Public Health, Erasmus Medical Center, Rotterdam, Netherlands

Community Medicine, United Arab Emirates University, Al Ain, United Arab Emirates

National AIDS and STI Control Programme, Ministry of Public Health and Sanitation, Nairobi, Kenya.

Correspondence to: Dr Lyle R. McKinnon, Department of Medical Microbiology, University of Nairobi, PO Box 19676-00202, Nairobi, Kenya (e-mail:

Supported by grants from the US President's Plan for AIDS Relief (PEPFAR) grant no. U62/CCU024510-05 to J.K. and L.G., and by the Canadian Institutes of Health Research (CIHR MOP 89983) to R.K.

Equal contributions were made for the article by P.I. and L.R.M. and also R.K. and J.K. The authors P.I., L.R.M., R.K., and J.K. designed the study; P.I., J.P., S.K., C.W., and J.K. provided and managed clinical care; P.I., L.R.M., J.M., S.K., W.K., and N.N analyzed the data; P.I., L.R.M., J.M., S.K., W.K., J.P., S.K., R.K., N.N., G.G., C.W., N.M., H.M., L.G., R.K., and J.K wrote the article.

The authors have no conflicts of interest to disclose.

Received May 21, 2012

Accepted September 10, 2012

© 2013 Lippincott Williams & Wilkins, Inc.