High HIV-1 prevalence, risk behaviours, and willingness to participate in HIV vaccine trials in fishing communities on Lake Victoria, Uganda

Introduction: HIV epidemics in sub-Saharan Africa are generalized, but high-risk subgroups exist within these epidemics. A recent study among fisher-folk communities (FFC) in Uganda showed high HIV prevalence (28.8%) and incidence (4.9/100 person-years). However, those findings may not reflect population-wide HIV rates in FFC since the study population was selected for high-risk behaviour. Methods: Between September 2011 and March 2013, we conducted a community-based cohort study to determine the population representative HIV rates and willingness to participate (WTP) in hypothetical vaccine trials among FFC, Uganda. At baseline (September 2011 - January 2012), a household enumeration census was done in eight fishing communities (one lakeshore and seven islands), after which a random sample of 2200 participants aged 18 - 49 years was selected from 5360 individuals. Interviewer-administered questionnaire data were collected on HIV risk behaviours and WTP, and venous blood was collected for HIV testing using rapid HIV tests with enzyme-linked immunosorbent assay (EIA) confirmation. Adjusted prevalence proportion ratios (adj.PPRs) of HIV prevalence were determined using log-binomial regression models. Results: Overall baseline HIV prevalence was 26.7% and was higher in women than men (32.6% vs. 20.8%, p < 0.0001). Prevalence was lower among fishermen (22.4%) than housewives (32.1%), farmers (33.1%) and bar/lodge/restaurant workers (37%). The adj.PPR of HIV was higher among women than men (adj.PPR = 1.50, 95%; 1.20, 1.87) and participants aged 30 - 39 years (adj.PPR = 1.40, 95%; 1.10, 1.79) and 40 - 49 years (adj.PPR = 1.41, 95%; 1.04, 1.92) compared to those aged 18 - 24 years. Other factors associated with HIV prevalence included low education, previous marriage, polygamous marriage, alcohol and marijuana use before sex. WTP in hypothetical vaccine trials was 89.3% and was higher in men than women (91.2% vs. 87.3%, p = 0.004) and among island communities compared to lakeshore ones (90.4% vs. 85.8%, p = 0.004). Conclusions: The HIV prevalence in the general fisher-folk population in Uganda is similar to that observed in the "high-risk'' fisher folk. FFC have very high levels of willingness to participate in future HIV vaccine trials.