A serosurvey of Haemophilus ducreyi, syphilis, and herpes simplex virus type 2 and their association with human immunodeficiency virus among female sex workers in Lagos, Nigeria

Background and Objectives: To determine the prevalence rates of serological reactivity of Haemophilus (H.) ducreyi, Treponema pallidum, and herpes simplex virus type 2 (HSV-2) antibodies among female sex workers (FSWs) and their association with human immunodeficiency virus (HIV) antibody status. Study Design: Cross-sectional, standard serological assays were used for syphilis, HSV-2 and HIV; a modified enzyme-linked immunosorbent assay (ELISA) was used to detect specific anti-H. ducreyi immunoglobulin (Ig) G and IgA antibodies. Results: Seroprevalence rates were 86% for anti-H. ducreyi IgG and 69% for anti-H. ducreyi IgA; 4% for rapid plasma reagin (RPR) and Treponema palladium hemagglutination assay (TPHA) confirmed syphilis; 59% for HSV-2; 12% for HIV-1 and 2% for HIV-2. Lower-class FSWs were significantly more likely than upper-class FSWs to be H. ducreyi seropositive (IgG: OR = 42.7; IgA: OR = 7.6) and have current or past syphilis infection (RPR: OR = 3.5; RPR and TPHA: OR = 4.5). The presence of syphilis increased significantly with older age (P-trend < 0.001). Non-Nigerian FSWs had significantly higher reactivity to chancroid (IgG: OR = 3.5; IgA: OR = 1.8) and borderline reactivity to syphilis (RPR: OR = 1.6; TPHA: OR = 2.0). A history of sex with non-Nigerian Africans was significantly associated with chancroid reactivity and borderline significant with syphilis serostatus. H. ducreyi seropositivity was significantly more likely in FSWs with HSV-2 (OR = 2.4) and syphilis (OR = 5.6). Chancroid and HSV-2 antibodies were also more common in HIV-infected FSWs.