Etiology :
Gnathostomiasis is a food-born parasite zoonosis causes by a round worm in the genus Gnathostoma e.g. G.spinigirum, G.hispidum. It can cause both cutaneous and visceral symptoms in humans.
Life cycle :
The adult worms live in gastric wall of tigers, dogs and cats that are definitive hosts. The female worms pass eggs in the hosts’ feces. In water, eggs become first stage larvae. After being ingested by cyclops that are the first intermediate hosts, they develop into second-stage larvae. When the second intermediate hosts (fish, birds, frogs, and snakes) ingest cyclops, the second stage larvae will develop into third stage larvae which are infective stage for humans and other definitive host. If dogs or cats, the definitive host, eat them, third stage larvae will develop into adult worms in the stomach wall. Humans are accidental host and the larvae will never develop into adult worms.
