ObjectiveFemale Genital Schistosomiasis (FGS) causes intravaginal lesions and symptoms that could be mistaken for sexually transmitted diseases or cancer. In adults, FGS lesions are refractory to treatment. The effect of treatment has never been explored in young women; it is unclear if gynaecological investigation will be possible in this young age group (16 – 23 years). We explored the predictors for accepting anti-schistosomal treatment and/or gynaecological reinvestigation in young women, and the effects of anti-schistosomal mass-treatment (praziquantel) on the clinical manifestations of FGS at an adolescent age.MethodThe study was conducted in randomly selected, rural, high schools in Ilembe, uThungulu and Ugu Districts, KwaZulu-Natal Province, East Coast of South Africa. At baseline, after obtaining ethical approval and informed consent, gynaecological investigations were conducted in female learners in grades 8 to 12 (aged 16-23 years). Mass-treatment was offered in the low-transmission season between May and August (a few in September), in accordance with WHO recommendations. Reinvestigation was offered after a median of 9 months (range 5-14 months). Univariate, multivariable and logistic regression analysis were used to measure the association between variables.ResultsOf the 2293 learners who came for baseline gynaecological investigations, 1045 (46%) had signs of schistosomiasis, 209/1045 (20%) had grainy sandy patches; 208/1045 (20%) homogenous yellow patches; 772/1045 (74%) had abnormal blood vessels; and 404/1045 (39%) were urine positive. Overall, only 26% (587/2293) learners participated in the mass treatment and 17% (401/2293) participated in the follow up gynaecological reinvestigations. More than 70% of learners with FGS lesions were lost to follow-up: 156/209 (75%) grainy sandy patches; 154/208 (74%) homogenous yellow patches; 539/722 (75%) abnormal blood vessels; 238/404 (23%) urine positive. The grade 12 pupil had left school and did not participate in the reinvestigations. Amongst those with lesions who came for both treatment and reinvestigation, 12 (of 19) still had grainy sandy patches, 8 (of 28) had homogenous yellow patches, and 54 (of 90) had abnormal blood vessels. Only 3 out of 55 remained positive forS. haematobiumova. The low mass treatment uptake and huge loss to follow up among those who had baseline FGS contributed to small sample size at follow up, to understand the effect of treatment. However, multivariable analysis showed that treatment had effect on the abnormal blood vessels (adjusted odds ratio = 2.1, 95% CI 1.1 – 3.9 and p 0.018). HIV, current water contact, water contact as a toddler and urinary schistosomiasis influenced participation in mass treatment. Grainy sandy patches, abnormal blood vessels, homogenous yellow patches, previous pregnancy, current water contact, water contact as a toddler and father present in the family were strongly associated with coming back for follow-up gynaecological investigation.ConclusionCompliance to treatment and gynaecological reinvestigation was very low. There is need to embark on large scale awareness and advocacy in schools and communities before implementing mass-treatment and investigation studies. Further investigations with large sample size are needed in order to fully understand the effect of treatment on FGS lesions, including the right timing for treatment.AUTHOR SUMMARYFemale genital schistosomiasis (FGS) is a neglected tropical disease and it affects many women and young girls in schistosomiasis endemic areas. A lot of research is still needed to understand the characteristics of FGS, its prevention, as well as the timing for treatment. As a result of the limited information, some women who suffer from FGS end up being diagnosed as suffering from diseases such as human papilloma virus or other sexually transmitted diseases. The study highlights issues that need to be taken into considerations when providing treatment or conducting mass treatment for schistosomiasis and FGS or planning gynaecological investigations to inform FGS control programmes. In this study of adolescent girls and young women of KwaZulu-Natal Province of South Africa, we sought to explore the factors that influence participation in mass treatment and gynaecological investigation, and investigating the effect of praziquantel treatment on FGS. Factors that influenced participation in mass treatment included HIV, current water contact, water contact as a toddler and urinary schistosomiasis. Factors that influenced participation in follow up gynaecological investigation included grainy sandy patches, abnormal blood vessels, homogenous yellow patches, previous pregnancy, current water contact, water contact as a toddler and father present in the family. There was low uptake and huge loss to follow up for mass treatment, and this contributed to small sample size for follow up gynaecological investigations to understand the effect of treatment. However, multivariable analysis showed that treatment had effect on the abnormal blood vessels and not on grainy sandy patches and homogenous yellow patches.