Thioredoxin glutathione reductase from Schistosoma mansoni: an essential parasite enzyme and a key drug target.

Background: Schistosomiasis--infection with helminth parasites in the genus Schistosoma, including S. mansoni--is a widespread, devastating tropical disease affecting more than 200 million people. No vaccine is available, and praziquantel, the only drug extensively utilized, is currently administered more than 100 million people yearly.