Prevalence and correlates of sexually transmitted infections in pregnancy in HIV-infected and- uninfected women in Cape Town, South Africa

OBJECTIVES: Sexually transmitted infections (STIs) are associated with adverse outcomes in pregnancy, including mother-to-child HIV transmission. Yet there are limited data on the prevalence and correlates of STI in pregnant women by HIV status in low- and middle-income countries, where syndromic STI management is routine. METHODS: Between November 2017 and July 2018, we conducted a cross-sectional study of consecutive pregnant women making their first visit to a public sector antenatal clinic (ANC) in Cape Town. We interviewed women ≥18 years and tested them for Chlamydia trachomatis (CT), Neisseria gonorrhoea (NG) and Trichomonas vaginalis (TV) using Xpert assays (Cepheid, USA); results of syphilis serology came from routine testing records. We used multivariable logistic regression to identify correlates of STI in pregnancy. RESULTS: In 242 women (median age 29 years [IQR = 24-34], median gestation 19 weeks [IQR = 14-24]) 44% were HIV-infected. Almost all reported vaginal sex during pregnancy (93%). Prevalence of any STI was 32%: 39% in HIV-infected women vs. 28% in HIV-uninfected women (p = 0.036). The most common infection was CT (20%) followed by TV (15%), then NG (5.8%). Of the 78 women diagnosed with a STI, 7 (9%) were identified and treated syndromically in ANC. Adjusting for age and gestational age, HIV-infection (aOR = 1.89; 95% CI = 1.02-3.67), being unmarried or not cohabiting with the fetus' father (aOR = 2.19; 95% CI = 1.16-4.12), and having STI symptoms in the past three days (aOR = 6.60; 95% CI = 2.08-20.95) were associated with STI diagnosis. CONCLUSION: We found a high prevalence of treatable STIs in pregnancy among pregnant women, especially in HIV-infected women. Few women were identified and treated in pregnancy.