Seroepidemiological Studies of Haemophilus ducreyi Infection in Ethiopian Women

Background and Objectives To measure prevalence of anti-Haemophilus ducreyi antibodies in sera from Ethiopian female attendees, and to determine significant socioeconomic associations. Study Design A modified ELISA immunoassay was used to test sera of 1,831 Ethiopian women attending gynecological, obstetric, and family planning clinics in Addis Ababa. Results Overall seropositivity was 19.4%. Prevalence rates for seropositivity for antibodies to H. ducreyi were significantly associated with ethnic group and religion, older age (≥50 years: 28%), early age at first coitus (<13 years: 28%) and first coitus before the menarche (25%), being divorced (27%) or a prostitute (24%), longer duration of marriage (>20 years: 27%) and sexual life (>20 years: 24%), number of lifetime sexual partners (2 to 5 partners: 27%) and self-reported history of both syphilis and gonorrhea (31%). Of these factors, the two most significant were first coitus before the menarche (P < 0.0001) and not being still married to the first husband/sexual partner (P <0.0001). Differences in seropositivity according to ethnic group and religion may be explained by the number of women within each group who had only one lifetime sexual partner. Women with serological evidence of exposure to another sexually transmitted disease (STD) had a greater risk of exposure to H. ducreyi. The odds ratio for H. ducreyi seropositivity in women with syphilis or gonorrhea was 3.6, for women with genital chlamydial infection, 2.3, and for those with HBV or HSV-2, 1.4 and 1.3 respectively. Conclusions This study illustrates the usefulness of the modified ELISA immunoassay for measuring exposure to H.ducreyi, and usefulness of H. ducreyi a marker for cumulative sexual exposure. Further studies on the association of HIV transmission and H. ducreyi in Ethiopia are now indicated.