The structure of the pore-forming peptide ofEntamoeba histolyticais similar to that known of membranolytic peptides, such as those present in the venom of wasps and bees and to the magainins of frog skin. New drugs with anticryptosporidial activity have been identified. A new staining technique that will allow easy identification of microsporidial spores has been described. Interventional radiology and endoscopy are finding a place in the nonsurgical treatment of hydatid disease, although the precise indications and contraindications for their use remain to be established. Tumor necrosis factor-α is the specific immune signal responsible for granuloma formation in schistosomiasis.