Heterogeneities in anti-schistosome humoral responses following chemotherapy

Schistosomiasis is a major public health problem in Africa, the Middle East , Asia and South America. The main control strategy is to treat infected pe ople with anthelmintic drugs, principally the safe and relatively cheap dru g praziquantel. Several treatment re-infection studies in humans have shown that praziquantel can have long-term effects beyond a transient reduction of infection intensity. These long-term effects include the altering of sch istosome-specific immune responses in humans which is associated with resis tance to re-infection. Differences have been observed in treatment-induced immunological changes between individuals and between populations. This art icle discusses the contributions of host- and parasite-related heterogeneit ies to post-treatment humoral responses in humans infected with Schistosoma mansoni and Schistosoma haematobium and considers the practical implicatio ns of such heterogeneity for schistosome immunoepidemiology studies.