Female Genital Schistosomiasis and HIV-1 incidence in Zambian women: a retrospective cohort study
Abstract Background Female genital schistosomiasis (FGS) has been associated with prevalent HIV-1. We estimated the incidence of HIV-1 infection in Zambian women with and without FGS. Methods Women (aged 18-31, non-pregnant, sexually active) were invited to participate in this study in January-August 2018 at final follow-up of the HPTN 071 (PopART) Population Cohort. HIV-1 negative participants at enrolment (n=492) were included in this analysis with testing to confirm incident HIV-1 performed in HPTN 071 (PopART). Association of incident HIV-1 infection with FGS (Schistosoma DNA detected by PCR in any genital specimen) was assessed with exact Poisson regression. Results Incident HIV-1 infections were observed in 4.1% (20/492) participants. Women with FGS were twice as likely to seroconvert as women without FGS but with no statistical evidence for a difference (aRR 2.16, 95%CI[0.21–12.30], p=0.33). Exploratory analysis suggested an association with HIV-1 acquisition among women with ≥2 positive genital PCR specimens (RR 6.02, [0.58–34.96]), p=0.13). Conclusions Despite higher HIV seroconversion rates in women with FGS, there was no statistical evidence of association, possibly due to low power. Further longitudinal studies should investigate this association in a setting with higher schistosomiasis endemicity.