In this article we will discuss about the life history of lung fluke (Paragonimus Westermani).
Although the majority of the adult specimens occur in the lungs, their digestive system can cope with a variety of food materials, because they occasionally found in tissues such as brain, liver, spleen, intestinal wall, eye, muscles or even kidneys. P. westermani passes its life cycle in three hosts—one definitive host and two intermediate hosts (Fig. 9.3).
Definitive host:
Man and carnivores especially cat family and dogs are the definitive hosts. Usual hosts in Asia are the tiger and leopard. Feline hosts serve as reservoir of infection.
Intermediate hosts:
First intermediate host:
In Oriental region, Semisulcospira libertina, S. amurensis and Thiara granifera, all once included in the genus Melania act as first intermediate host. Yogore (1958) found Brotia asperata to be the first intermediate host in the Philippines.
Second intermediate host:
Crustacea especially a fresh water Cray fish or a crab acts as second host. In Japan Crab-Eriocheir japonicus, Potamondehaii; in Philippines Crab-Parathelphusa sp. and in USA Cray fish-Cambarus sp. are second hosts.