P40.08
Background: Most HIV transmissions occur in women following exposure to virus in the female genital tract (FGT). Because FGT inflammation has been associated with increased risk of HIV acquisition, it is critical to understand the biologic and behavioral factors that may contribute to elevated FGT inflammation. The KwaZulu-Natal (KZN) region in South Africa has one of the highest rates of intra-vaginal drying agent (IDA) usage worldwide. However, little is known about the immunologic effects of these agents, specifically as they relate to genital inflammation and risk of HIV acquisition.
Methods: FGT samples and detailed behavioral data were collected from a high-risk cohort of young, HIV-negative women in KZN. Cytobrush cells were assessed by flow cytometry. FGT mononuclear cells and cervical tissue explants were incubated with drying agents in vitro and assessed for changes in immune activation.
Results: Overall, 15.2% of the cohort reported using IDAs. The most commonly used agents were “ntsu” (powdered tobacco) and “china fruit.” Associations were seen between IDA use and earlier sexual debut (p=0.0305), older sexual partners (p=0.0073), frequency of sex (p=0.0373) and, importantly, increased HIV acquisition rates (p=0.0015). IDA use was also associated with altered frequencies and activation states of immune populations at the cervicovaginal junction. Several common IDAs were shown to have effects on immune activation on FGT mucosal cells and cervical explants in vitro.
Conclusions: This study describes the behavioral and immunological associations of IDA usage and their potential impact on HIV acquisition. It reveals increased acquisition rates among those who use IDA that are likely due to both behavioral and biological factors. This work lays the foundation for future research on therapies and behavioral interventions to modulate the immune landscape in the FGT to prevent HIV acquisition.
