Treatment of Female Genital Schistosomiasis (FGS) With Praziquantel: A Proof-of-Concept Study

Overview

Female genital schistosomiasis (FGS) is a frequent manifestation of the infection with Schistosoma haematobium or mansoni. FGS is probably the most neglected gynaecological condition in the tropics. Inflammation of genital tissue persists as long as adult worms are present in the circulation, and new eggs are released. Hence, lesions can only heal if the inflammation is abated and a normal immune response is restored A randomized controlled study will be carried out to compare the efficacy of the standard treatment with that of five repeated doses of praziquantel. Outcome measure is the disappearance/regression of clinical pathology at the cervix, in the vagina/vulva.

Female genital schistosomiasis (FGS) is a frequent manifestation of the infection with Schistosoma haematobium or mansoni. It occurs in women of all age groups, including young girls and is associated with important, frequently debilitating and stigmatizing morbidity. It may develop into a life-threatening condition. FGS is probably the most neglected gynaecological condition in the tropics. Depending on where eggs are released the clinical pathology develops in vulva and vagina, cervix, uterus, Fallopian tubes and the ovaries. All genital organs may be affected simultaneously. Women with FGS report spontaneous, or post-coital bleeding, vaginal discharge, pain during sexual intercourse, pelvic pain, irregular menstruation and infertility. Vaginal discharge and itching, pain during sexual intercourse, spontaneous + post-coital bleeding, as well as menstruation abnormalities are attributed by the women to STIs. This results in shame, mental strain and distress, eventually causes stigmatization and social exclusion leading to an impaired life quality. Clinical, histopathological, immunological and epidemiological evidence suggests that there is a cause-effect relationship between FGS and HIV infection. There are hints of a cause effect relationship between FGS and HPV. The association of FGS with HIV /HPV infection underlines the pivotal importance for an effective treatment of FGS. Clinical pathology is the result of a complex inflammatory response to antigens released by adult worms and viable eggs. The inflammation of genital tissue persists as long as adult worms are present in the circulation, and new eggs are released and become trapped. Hence, lesions can only heal if the inflammation is abated and a normal immune response is restored. This means that all worms have to be eliminated and reinfection has to be prevented for some time to allow complete healing of genital organs. Based on this rationale, five doses of praziquantel will be given over a period of 10 weeks to ensure that all existing worms will be eliminated. The first three doses aim to kill all adult worms. The fourth dose will kill schistosomula which will mature in the following weeks. The last dose will prevent women from re-infection. A randomized controlled study will be carried out to compare the efficacy of the standard treatment with that of repeated doses of praziquantel. Since a placebo is not available, the study will not be blinded. Outcome measure is the disappearance/regression of clinical pathology at the cervix, in the vagina/vulva. The result of this study has important implications for the sexual health of millions of women in sub-Saharan Africa. The aim of the study is to compare standard treatment of schistosomiasis as recommended by WHO (a single dose of praziquantel 40 mg/kg)- with a treatment based on a new rationale: five doses of praziquantel 40 mg/kg * 1 x 40 mg/kg after enrollment in the study (D1, H0) plus two single doses (40 mg/kg) after 12 and 24 hours after the first treatment * 1 x 40 mg/kg five weeks following the 1st PZQ treatment * 1 x 40 mg/kg ten weeks following the 1st PZQ treatment