Evaluating Chlamydia trachomatis and Neisseria gonorrhea among women who initiated HIV Pre-exposure Prophylaxis during pregnancy in Kenya

Abstract

Cisgender women in the World Health Organization (WHO) Africa region are at a double burden of HIV and other curable sexually transmitted infections (STIs), such as Chlamydia trachomatis (CT) and Neisseria gonorrhea (NG). Countries in the region, including Kenya, have made tremendous efforts to incorporate HIV pre-exposure prophylaxis (PrEP) for HIV prevention and routine screening for syphilis within maternal and child health settings. However, syndromic management, which broadly covers several STI types, remains the standard of care for curable STIs other than syphilis, often leading to delayed or missed treatment opportunities and antimicrobial resistance due to overtreatment. Studies within the region have found that the use of ’near patient’ laboratory-based testing for CT/NG is feasible and acceptable. Additionally, empiric testing is associated with fewer missed treatment opportunities due to its high sensitivity and specificity in detecting asymptomatic infections. Data shows a high prevalence of CT/NG among non-pregnant PrEP users; however, limited data exists on pregnant women using PrEP. Additionally, few studies prospectively follow-up PrEP users to evaluate the incidence of CT/NG. While uptake of PrEP among pregnant women with characteristics associated with HIV exposure is high, many women discontinue PrEP soon after initiation. Since STIs are common both in pregnant and non-pregnant women, routine testing for CT/NG among women using PrEP could potentially refine risk perception and motivate PrEP use. As countries seek to expand STI testing services within PrEP programs, it is critical to explore user experiences and women’s motivation for CT/NG testing during the peripartum period. The studies presented in this dissertation aim to address the above epidemiologic and implementation gaps to advance delivery of STI testing for pregnant and postpartum women on PrEP in the WHO Africa region. To add to the existing literature on the burden of CT/NG among pregnant women, we present the prevalence, incidence, and correlates of CT/NG among women who initiate PrEP in pregnancy within routine maternal and child health settings in Kenya. Using prospective data that tested women for CT/NG in pregnancy, 6 months, and 9 months, we found a appreciable prevalence and high incidence of CT/NG. These data contribute to the limited longitudinal studies evaluating the incidence of CT/NG among PrEP users in maternal and child health settings. Using data from a randomized control trial, we present findings examining the relationship between CT/NG testing on PrEP discontinuation. We found that testing for CT/NG in pregnancy was associated with lower PrEP discontinuation as compared to testing after delivery. Finally, to complement our quantitative findings, we assessed user experiences of receiving CT/NG testing integrated within PrEP delivery. Women’s individual motivations for CT/NG testing uptake and how testing influenced HIV and STI risk perception provides valuable insights to add to guide future implementation models. The studies presented in this dissertation aim to address the evidence gaps on the burden of CT/NG among pregnant PrEP users, the association between CT/NG testing and PrEP use, and user experiences of testing among pregnant and postpartum women in Kenya.