Association Between Female Genital Schistosomiasis and High-Risk Human Papillomavirus Among Women of Reproductive Age in Zambia: The Schista Study.

BACKGROUND

Female genital schistosomiasis (FGS), a gynecological disease caused by Schistosoma haematobium egg deposition in the female genital tract, is prevalent in sub-Saharan Africa, the region with the highest cervical cancer burden globally. Persistent high-risk human papillomavirus (HR-HPV) infection is necessary for cervical cancer development. We determined the association between FGS and HR-HPV genotypes in Zambian women.

METHODS

Sexually active women aged 15-50 years, not menstruating or pregnant, were recruited at home and provided 2 cervicovaginal self-swabs, urine sample, and HIV and Trichomonas vaginalis self-tests, and completed a questionnaire. In clinic, midwives collected cervicovaginal swabs and cervical images with point-of-care colposcopy (EVA System, MobileODT). Swabs were analyzed for 14 HR-HPV types (GeneXpert) and Schistosoma DNA (ITS-2 real-time polymerase chain reaction [qPCR]); urine was analyzed for Schistosoma ova by microscopy and circulating anodic antigen. Visual FGS was defined as colposcopic identification of specific genital lesions, and molecular FGS as Schistosoma-positive cervicovaginal qPCR.

RESULTS

Among 2532 women (median age, 28 [interquartile range, 22-36] years) recruited at home, 1694 (67%) completed clinic follow-up. Prevalence of visual FGS, molecular FGS, and HR-HPV was 35.2% (595/1691), 6.5% (165/2532), and 28.7% (690/2401), respectively. Molecular FGS was weakly associated with all HR-HPV (adjusted odds ratio [aOR], 1.3 [95% confidence interval {CI}, .9-1.9]). Women with molecular FGS were more likely to test positive for HR-HPV types 16/18/45 (aOR, 1.7 [95% CI, 1.0-2.8]). No association was observed between visual FGS and HR-HPV infection (95% CI, .7-1.1).

CONCLUSIONS

This is the first study to jointly screen for FGS and HR-HPV in Zambia, reporting an association between oncogenic HR-HPV types and molecular FGS.