Demographic and behavioural risk factors associated with Trichomonas vaginalis among South African HIV-positive men with genital ulcer disease: a cross-sectional study

OBJECTIVES: Demographic and risky sexual behaviours may increase the risk for Trichomonas vaginalis (TV) infection and, thus, enhance HIV transmission to uninfected partners. We assessed the demographic and behavioural risk factors associated with TV among South African HIV-positive men with genital ulcer disease. METHODS: We conducted a cross-sectional study with data from a randomised controlled trial conducted by the Centers for Disease Control and Prevention and the London School of Hygiene and Tropical Medicine. The data were obtained from three primary healthcare clinics in South Africa. At baseline (n=387), participants reported on demographics, sexual behaviour, history of sexually transmitted infections and clinical ulcers. The outcome TV was measured using real-time multiplex PCR assays and a Rotor-gene 3000 platform from the first and past urine samples of all participants. Logistic regression model estimated ORs and 95% CIs adjusted for demographics, sexual risk behaviours and ulcer conditions. RESULTS: An estimated 11.4% of TV was detected among the men. The odds of TV infection were significantly associated with high blister counts (OR 4.0, 95% CI 1.6 to 28, p=0.01), ulcer pain (OR 0.4, 95% CI 0.2 to 0.7, p=0.003), number of days with ulcers (OR 0.4, 95% CI 0.2 to 0.8, p=0.006), sought treatment before coming into clinics (OR 0.07, 95% CI 0.002 to 0.7, p=0.005) and being unqualified worker (OR 2.5, 95% CI 0.9 to 6.7 p=0.05). Multivariate analyses revealed that increased days with ulcers (OR 0.1, 95% CI 0.04 to 0.5, p=0.002) and ulcer pain intensity (OR 0.08, 95% CI 0.007 to 1.1, p=0.05) remained significantly associated with decreased odds of TV infection. Men from the Sotho ethnic group were eight times more likely to have TV infection (OR 8.6, 95% CI 1.3 to 55.7, p<0.02) than men from the other ethnic groups. CONCLUSION: HIV-positive men with severe ulceration should be screened and treated for TV to minimise HIV transmission to uninfected partners.