[Last Modified: ]
[Schistosoma haematobium] [Schistosoma intercalatum] [Schistosoma japonicum] [Schistosoma mansoni] [Schistosoma mekongi]

The intermediate hosts of Schistosoma spp. are various species of freshwater snails.  Eggs are shed from the human host in feces or urine.  Under optimal conditions in the environment, the eggs hatch and release miracidia, which swim and penetrate specific snail intermediate hosts.  The stages in the snail include two generations of sporocysts and the production of cercariae.  Upon release from the snail, the infective cercariae swim and penetrate the skin of the human host, where maturation of the worms continues.  Oncomelania spp. are the intermediate hosts for S. japonicum, while Neotricula spp. are the intermediate hosts for S. mekongi.  Biomphalaria spp. are the intermediate hosts for S. mansoni, both in the New and Old Worlds.  Bulinus spp. are the intermediate hosts for S. haematobium and S. intercalatum.

A	B

A:  Biomphalaria sp., the intermediate host for S. mansoni.
B:  Bulinus sp., the intermediate host for S. haematobium and S. intercalatum.

C

C:  Oncomelania sp., the intermediate host for S. japonicum.