Schistosomosis

Abstract

Schistosomes are trematode parasites that propagate in snails, mammals and birds. The invertebrate snail is the intermediate host and vertebrate hosts are definitive hosts. The disease produced in humans and animals by the different parasitic species of the genus Schistosoma is called schistosomosis. All species of Schistosoma that infect human beings either have non-human origin, or animals act as reservoirs or carriers of the parasite. Human schistosomosis is a public health burden and a zoonotic problem. Human schistosomosis has primarily two forms, intestinal and urogenital. Other forms like pulmonary, hepatic and neural schistosomosis also occur. Forms of animal schistosomosis are hepato-intestinal or nasal. The drugs for treatment and chemoprophylaxis of human and animal schistosomosis are limited. Praziquantel is the only drug available and recommended by the World Health Organization (WHO) for its mass drug administration protocol aimed towards schistosomosis elimination in endemic locations. The schistosomosis control programmes are affected by the drug's high cost. The high cost of praziquantel also makes treatment of animal schistosomosis in field conditions almost impractical. Control measures include control of the snail host population, provision of proper sanitary conditions and limiting animals’ access to water bodies used by human beings. Animal and human schistosomosis are prevalent in countries with poor economies and poor resources. There are many diagnostic methods for identification of schistosomosis. Affordable and field-applicable diagnostic methods are the best for control and treatment of schistosomosis. Efforts are being made for the development of vaccines for human and animal schistosomosis. Recombinant antigens like Glutathione S Transferase, Tetraspanins, Paramyosin, Fatty acid binding protein and Triose-Phosphate Isomerase are under clinical trials. © 2026 selection and editorial matter, Snehil Gupta, Arun Kumar De, Perumal Ponraj, and Debasis Bhattacharya; individual chapters, the contributors.