HIV-1, HSV-2 and syphilis among pregnant women in a rural area of Tanzania: Prevalence and risk factors

Background: Evidence suggests that a substantial proportion of new HIV infections in African countries are associated with herpes simplex virus type 2 ( HSV-2). Thus, the magnitude of HSV-2 infection in an area may suggest the expected course of the HIV epidemic. We determined prevalence of genital herpes, syphilis and associated factors among pregnant women from a remote rural Tanzanian community that has a low but increasing HIV prevalence. Methods: We analysed 1296 sera and responses to a standard structured questionnaire collected from pregnant women aged between 15-49 years, attending six different antenatal clinics within rural Manyara and Singida regions in Tanzania. Linked anonymous testing ( with informed consent) of the serum for specific antibodies against HSV-2 was done using a non-commercial peptide- 55 ELISA. Antibodies against syphilis were screened by using rapid plasma reagin ( RPR) and reactive samples confirmed by Treponema pallidum haemagglutination assay ( TPHA). Results: Previous analysis of the collected sera had shown the prevalence of HIV antibodies to be 2%. In the present study the prevalence of genital herpes and syphilis was 20.7% ( 95% CI: 18.53-23.00) and 1.6% ( 95% CI: 1.03-2.51), respectively. The presence of HSV-2 antibodies was associated with polygamy ( OR 2.2, 95% CI: 1.62-3.01) and the use of contraceptives other than condoms ( OR 1.7, 95% CI: 1.21-2.41). Syphilis was associated with reporting more than one lifetime sexual partner ( OR 5.4, 95% CI: 1.88-15.76) and previous spontaneous abortion ( OR 4.3, 95% CI: 1.52-12.02). Conclusion: The low prevalence of HIV infection offers a unique opportunity for strengthening HIV prevention in a cost-effective manner. The identification and control of other prevalent curable STIs other than syphilis and specific intervention of HSV-2 in specific populations like pregnant women would be one among approaches towards preventing incident HIV infections.