Background:  Sexually transmitted diseases (STD) are associated with HIV. Schistosoma (S.) haematobium has found to be been associated with friable, bleeding lesions and immunologically active cells in female genital mucosa. We wished to determine the association between female genital S. haematobium infection HIV.

Methdods:  A cross-sectional study, with a 1-year follow-up, was done in a rural Zimbabwean community. Gynecological and laboratory investigations were done for S. haematobium and HIV. STD, demographic, and urogenital history were analyzed as confounders. S. haematobium related lesions had been found in 46% of the women, 29% had HIV and 65% had herpes simplex type-2 (HSV-2).

Results:  We included 527 sexually active, non-pregnant, non-menopausal women between the ages of 20 and 49 years, 83% of the eligible community members at 4 pick-up points. In the permanent rural residents (>3 years residency), HIV was found in 41% (29 of 70) of the women with laboratory proven genital schistosomiasis as opposed to 26% HIV⁺ (96 of 375) in the schistosomal ova negative group (OR 2.1; 95%CI 1.2 to  3.5; p = 0.008). S. haematobium infection of the genital mucosa was significantly associated with HIV seropositivity (adjusted OR 2.9, 95%CI 1.11 to 7.5, p = 0.030). The relationship between S. haematobium and HIV remained associated in multivariate analysis after adjustments for STD, widowhood, and infertility. All 7 women who became HIV⁺ in the study period (seroincidence 3.1%) had signs of S. haematobium at baseline. Body mass index did not influence the associations; CD4 count was regrettably not available. In accordance with previous reports HIV was significantly associated with HSV-2, syphilis, and human papillomavirus. Adjusted for confounders, women with genital schistosomiasis had an almost 3-fold odds ratio of having HIV in this rural Zimbabwean community. S. haematobium may be hypothesized to predominate as a cause of mucosal susceptibility in certain geographic areas.

Conclusions:  In S. haematobium-endemic areas, HIV may have spread with genital schistosomiasis, rather than STD, as an essential risk factor for heterosexual transmission. This study indicates that schistosomiasis control may perhaps be an important auxiliary in HIV prevention. The possibility of reduced HIV transmission in schistosomiasis-endemic areas adds new intervention points in the battle against HIV. Prospective studies are needed to confirm the association.