High HIV risk in a cohort of male sex workers from Nairobi, Kenya.

OBJECTIVES: Men who have sex with men (MSM) are at high risk of HIV-1 acquisition and transmission, yet there remains limited data in the African context, and for men who sell sex to men (MSM SW) in particular. METHODS: We enrolled 507 male sex workers in a Nairobi-based prospective cohort study during 2009-2012. All participants were offered HIV/STI screening, counselling and completed a baseline questionnaire. RESULTS: Baseline HIV prevalence was 40.0% (95% CI 35.8% to 44.3%). Prevalent HIV infection was associated with age, less postsecondary education, marijuana use, fewer female partners and lower rates of prior HIV testing. Most participants (73%) reported at least two of insertive anal, receptive anal and insertive vaginal sex in the past 3 months. Vaginal sex was reported by 37% of participants, and exclusive MSM status was associated with higher HIV rates. Condom use was infrequent, with approximately one-third reporting 100% condom use during anal sex. HIV incidence was 10.9 per 100 person-years (95% CI 7.4 to 15.6). Predictors of HIV risk included history of urethral discharge (aHR 0.29, 95% CI 0.08 to 0.98, p=0.046), condom use during receptive anal sex (aHR 0.05, 95% CI 0.01 to 0.41, p=0.006) and frequency of sex with male partners (aHR 1.33/sex act, 95% CI 1.01 to 1.75, p=0.04). CONCLUSIONS: HIV prevalence and incidence were extremely high in Nairobi MSM SW; a combination of interventions including increasing condom use, pre-exposure prophylaxis and access to effective treatment is urgently needed to decrease HIV transmission in this key population.

Using diaries to measure parameters of transactional sex: an example from the Trans-Africa highway in Kenya.

Conventional methods of elicitation have severe limitations where sensitive information is being sought, resulting from both self-disclosure and recall bias. The use of diaries largely circumvents both of these problems. Four hundred and three female sex workers based on a section of the Trans-Africa Highway in Kenya completed standard diaries for consecutive 28-day periods. Variables measured included numbers and types of different clients, condom use, occupation of client, movement patterns and days of menses. Mean numbers of sexual partners, liaisons and sex acts and inter-relationships between the variables measured are analysed. The study affirms the value of diaries as an elicitation method for studying transactional sex in a resource-poor setting. Usable diaries were received from 70% of those who had agreed to participate in the study. The diaries yield detailed quantitative data that describe the characteristics and dynamics of transactional sex on a major highway in Africa and provide information that may be used to estimate HIV transmission rates.