Angiostrongyliasis (eosinophilic meningoencephalitis) is an infestation of the brain and surrounding membranes (meninges) by the nematode worm Angiostrongylus cantonensis. It occurs on Pacific islands, in West Africa, south Asia and in the Caribbean.
The worms of Angiostrongyliasis, normally live in the gut of rats. Their eggs pass out with rat faeces, are eaten by snails, prawns or fish, and then pass to humans if these foods are eaten when poorly cooked. They may directly enter humans if food contaminated by rat faeces (e.g. salads) are eaten. The swallowed eggs hatch into larvae, which migrate through the bloodstream to the brain and meninges. The incubation period is one to three weeks.
Patients develop a severe headache, fever, neck stiffness, nausea, vomiting and abnormal nerve sensations. The worms may spread into the eye and cause blindness. CT and MRI scans may show the presence of worms in brain.
No specific treatment is available. Symptoms persist for several months until the worm dies, and then most patients recover completely. Rarely there may be permanent brain damage and death.