NOVEL CHEMOTHERAPEUTIC TARGETS FOR THE CONTROL OF SCHISTOSOMIASIS

ABSTRACT

     Schistosomiasis is a water-borne parasitic disease caused by schistosomes and transmitted by fully aquatic or amphibious freshwater snails in whose bodies the human-infective larvae, cercariae, develop. Adult schistosome worms colonise human blood vessels for years, successfully evading the immune system while excreting hundreds to thousands of eggs daily, which must either leave the body in excreta and/or urine or become trapped in nearby tissues. Trapped eggs induce a distinct immune-mediated granulomatous response that causes local and systemic pathological effects ranging from anaemia, growth stunting, impaired cognition, and decreased physical fitness, to organ-specific effects such as severe hepatosplenism, periportal fibrosis with portal hypertension, and urogenital inflammation and scarring. The disease is more common in school aged children. At present, preventive public health measures in endemic regions consist of treatment once every 1 or 2 years with the isoquinolinone drug, praziquantel (PZQ), to suppress morbidity. In some locations, elimination of transmission is now the goal; however, more sensitive diagnostics are needed in both the field and clinics, and integrated environmental and health-care management will be needed to ensure elimination. This paper reviews potential chemotherapeutic targets that could be exploited for the development of new antischistosomal drugs.