Association Between Cervical Dysplasia and Female Genital Schistosomiasis Diagnosed by Genital PCR in Zambian Women

Abstract Background: Female genital schistosomiasis (FGS) is a neglected tropical gynaecological disease that affects millions of women in sub-Saharan Africa (SSA). FGS is caused by Schistosoma (S.) haematobium, a parasitic carcinogen involved in the pathogenesis of squamous cell carcinoma of the bladder. Cervical cancer incidence and mortality are highest in SSA, where pre-cancerous cervical dysplasia is often detected on screening with visual inspection with acetic acid (VIA). No studies have evaluated the association between VIA positivity and FGS diagnosed by genital PCR. Methods: Women were recruited from the BILHIV study in Zambia, which compared genital self-sampling to provider obtained cervicovaginal-lavage for the diagnosis of FGS in women aged 18-31. FGS was defined as positive Schistosoma DNA from any genital PCR. Urogenital schistosomiasis diagnostics included urine circulating anodic antigen, urine microscopy and portable colposcopy. Participants were offered cervical cancer screening using VIA at Livingstone Central Hospital. Associations of PCR confirmed FGS and other diagnostics with VIA positivity were assessed using multivariable logistic regression.Results: VIA results were available from 237 BILHIV participants. A positive Schistosoma PCR in any genital specimen was detected in 14 women (5.9%), 28.6% (4/14) of these women had positive VIA compared to 9.0% (20/223) without PCR evidence of schistosome infection. Schistosoma PCR positivity in any genital specimen was strongly associated with VIA positivity (OR: 6.08, 95% CI: 1.58-23.37, P=0.02). Conclusions: This is the first study to find an association between FGS and positive VIA, a relationship that may be causal. Further longitudinal studies are needed.