High prevalence and incidence of sexually transmitted infections among women living in Kwazulu-Natal, South Africa

Background and objectives: Sexually transmitted infections (STIs) contribute largely to the burden of health in South Africa and are recognized as major contributors to the human immunodeficiency virus (HIV) epidemic. Young women are particularly vulnerable to STIs. The purpose of this secondary analysis was to examine the risk factors associated with prevalent and incident STIs among women who had participated in three clinical trials. Methods: A total of 5,748 women were screened and 2293 sexually active, HIV negative, non-pregnant women were enrolled in three clinical trials in Kwazulu-Natal, South Africa. The prevalence of individual STIs Chlamydia trachomatis (CT), Neisseria gonorrhea (NG), syphilis, and Trichomonas vaginalis (TV) was assessed at screening; and incident infections were evaluated over a 24 month period. Results: Overall, the combined study population of all three trials had a median age of 28 years (inter-quartile range (IQR):22-37), and a median duration of follow-up of 12 months. Prevalence of STIs (CT, NG, TV, or syphilis) was 13% at screening. The STI incidence was estimated to be 20/100 women years. Younger women (<25 years, p < 0.001), women who were unmarried (p < 0.001) and non-cohabiting women (p < 0.001) were shown to be at highest risk for incident STIs. Conclusions: These results confirm the extremely high prevalence and incidence of STIs among women living in rural and urban communities of KwaZulu-Natal, South Africa, where the HIV epidemic is also particularly severe. These findings strongly suggest an urgent need to allocate resources for STI and HIV prevention that mainly target younger women.