RELATIONSHIPS BETWEEN CHEMOTHERAPY AND IMMUNITY IN SCHISTOSOMIASIS

This chapter focuses on the relationships between chemotherapy and immunity in schistosomiasis. A sizeable literature dealing with the relationships between the chemotherapeutic efficacy of antischistosomal drugs and host immunological responses to schistosomes is now available, and this literature forms the basis of this chapter. More general information on the immune dependence of chemotherapy in other parasitic infections is available. Schistosomiasis is the most important of the human helminthiases––it is responsible for the death of thousands of people each year and for inestimable morbidity. Various forms of schistosomiasis afflict up to 300 million people in tropical Asia, Africa, South America, and the Caribbean, with a further 600 million people at risk of infection in endemic regions and it is spreading. The disease is transmitted by contact with contaminated water and is caused by various species of blood flukes of the genus Schistosoma, which live and lay eggs in the veins of the intestines (Schistosoma mansoni, S. japonicum, and S. mekongi) or bladder (S. haematobium and S. intercalatum). Chemotherapy is employed to treat schistosomiasis and to control its spread. Chemotherapy of schistosomiasis began at the time of the First World War when tartar emetic (potassium antimony tartrate) was administered to patients with schistosomiasis haematobia. Schistosomes exhibit inherent insusceptibility to schistosomicidal compounds not only with respect to particular drugs but also with respect to species, strain, sex, and age of the parasites. Similarly to experimental studies on the immune dependence of schistosomicidal chemotherapy with antimonials, the immune dependence of antischistosomal chemotherapy of hycanthone and oxamniquine has been examined using experimental S. mansoni infections in mice. © 1994 Academic Press Limited