ACQUIRED-IMMUNITY ON A SCHISTOSOMIASIS TRANSMISSION MODEL - FITTING THE DATA

A semi-stochastic model is proposed to analyse the effects of acquired immunity on the transmission of schistosomiasis in the human host. Th e basic model's assumptions are as follows. The human host is assumed to build up an immune response after elapsing a fixed period of time L from the first infection. This acquired immunity is assumed to be par tially effective and it is never lost. The parasite infection event is a Poisson process with multiple occurrences, i.e., in each event one or more cercaria are assumed to invade the host. The model treats dete rministically the age distribution of human host. The model shows a go od retrieving capacity of real data from two endemic areas of schistos omiasis: Touros, Brazil (Schistosoma mansoni) and Misungwi, Tanzania ( Schistosoma haematobium). (C) 1997 Academic Press Limited.