Vaccines for schistosomiasis

Article By:

McManus, Donald P. Molecular Parasitology Laboratory, Queensland Institute of Medical Research, Queensland, Australia.

Last reviewed:2010

DOI:https://doi.org/10.1036/1097-8542.YB100015

Schistosomiasis, caused by trematode blood flukes of the genus Schistosoma, is the most important human helminth disease in terms of morbidity and mortality. The three major species infecting humans are Schistosoma mansoni (which occurs in much of sub-Saharan Africa, areas of South America, the Caribbean, Egypt, and the Arabian peninsula), S. haematobium [present in much of sub-Saharan Africa, Egypt, Sudan, the Maghreb (northwestern Africa), and the Arabian peninsula], and S. japonicum (endemic to southern China and the Philippines, with small foci in Indonesia). Schistosoma haematobium infections cause fibrosis, stricturing, and calcification of the urinary tract, whereas the other two species have well-described associations with chronic hepatic and intestinal fibrosis and their attendant consequences. Despite the existence of a highly effective antischistosome drug, praziquantel (PZQ), schistosomiasis is spreading into new areas, and, although it is the cornerstone of current control programs, PZQ chemotherapy does have limitations. Mass treatment does not prevent reinfection, and there is increasing concern about the development of parasite resistance to PZQ. Consequently, vaccine strategies represent an essential component for future control of schistosomiasis. An improved understanding of the immune response to schistosome infection, both in animal models and in humans, suggests that development of an effective vaccine is possible, although this goal has yet to be achieved.

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