Schistosomiasis is a major parasitic disease of humans in the developing world, ranking second only to malaria in terms of morbidity. More than 200 million people are infected with schistosomes, of whom a proportion suffer significant morbidity, and re-evaluation of DALY (disability life adjusted years) estimates calls for a major 4-30-fold increase in DALY weighting. Consequently, schistosome infections impose considerable burden on the socio and economic development of communities in endemic countries.
Presently, control can be achieved by use of praziquantel, a cost-effective drug with good efficacy but there are limitations. As such, reliance on a single drug in mass treatment campaigns is dangerous due to the possible emergence of drug-resistance, particularly in areas of high disease transmission, and in individuals with heavy infection. An alternative control strategy would be to develop an effective vaccine; this is desirable since drug treatment does not confer protection to re-infection.
WHO - World Health Organisation