Schistosoma mansoni is the common human blood fluke . It belongs to class-Trematoda of Platyhelminthes. Blood fluke is digenetic, primary host is man and secondary host is snail.Sheep is the primary host of Fasciola hepatica (sheep liver fluke), causing 'liver rot'. Its secondary host is also the snail.
Mosquito and housefly do not found to be the intermediate host of any animal.