Antibody to Haemophilus ducreyi among trucking company workers in Kenya.

BACKGROUND AND OBJECTIVES To determine the prevalence, correlates, and incidence of Haemophilus ducreyi antibodies, a cohort of East African trucking company employees was evaluated. STUDY DESIGN Human immunodeficiency virus (HIV)-1-seronegative men working in six trucking companies in Mombasa, Kenya, were evaluated with a questionnaire and serologic testing for antibodies to H. ducreyi and other sexually transmitted pathogens. Men who were initially H. ducreyi seronegative were retested at 1 year of follow-up. RESULTS The H. ducreyi seroprevalence among 501 men at enrollment was 26.5%. Seropositivity was significantly associated with older age, married status, years of active sex life, number of sex partners in the past year, history of unprotected sex with a prostitute in the past year, and history of alcohol intake (all P values < 0.01). Occupational travel for more than 14 days per month was also significantly associated with H. ducreyi seropositivity (odds ratio [OR] 2.1, 95% confidence interval [CI] 1.3-3.2). Using multivariate analysis, H. ducreyi seropositivity was independently associated with age, married status, history of sex with a prostitute, and history of alcohol intake. Presence of H. ducreyi antibodies was significantly associated with seropositivity to the other major genital ulcerative pathogens, Treponema pallidum (OR 4.3, 95% CI 2.2-8.3), herpes simplex virus type 2 (OR 4.9, 95% CI 2.0-11.5), and Chlamydia trachomatis (OR 3.2, 95% CI 1.5-6.9). These associations remained significant after adjusting for demographic and exposure variables. The incidence of seroconversion to H. ducreyi antibodies was 3.6 per 100 person years. CONCLUSIONS Serologic evidence of H. ducreyi infection was common among male trucking company employees. H. ducreyi seropositivity is an objective marker of high-risk behavior and is associated with serologic evidence of other ulcerative sexually transmitted diseases.