Experimental Chemotherapy of Schistosomiasis mansoni

Abstract

For many practical and economical reasons, the major portion of experimental work with schistosomes is carried out with Schistosoma mansoni. Although the life cycle of S. haematobium has been successfully maintained under laboratory conditions, this species is not very suitable for experimental chemotherapy (difficulty of infecting the snail vectors; loss of the predilection of this species for the urogenital tract in small laboratory animals, etc.). S. japonicum life cycle is difficult to perpetuate in the laboratory and this species is known to be the most resistant to treatment with all available antischistosomal agents. Therefore, S. mansoni is the fluke of choice for experimental work. A schistosomicide does not merely have to be active against the worm and inactive against the host; it needs more qualities. The great drawbacks to the chemotherapy of schistosomiasis are the side effects and insufficient activity. The first properties of the perfect drug are therefore: (1) absence of side effects and toxicity in man, and (2) very high activity against the three main human schistosomes. The development of new drugs for the chemotherapy of schistosomiasis has followed three major lines: the empirical, the selective, and the biochemical. These novel drugs are also considered in the chapter with emphasis on niridazole and hycanthone, which proved to have a remarkable therapeutical activity in clinical schistosomiasis mansoni.