Which parasite is responsible for eosinophilic meningoencephalitis with symptoms like fever and headache?

The parasite responsible for eosinophilic meningoencephalitis, characterized by symptoms such as fever and headache, is Angiostrongylus cantonensis. This roundworm, commonly known as the rat lungworm, primarily infects rodents but can also cause illness in humans when they mistakenly ingest larvae present in contaminated food or water, particularly in areas where the parasite is endemic.

Once inside the human host, the larvae can migrate to the central nervous system, leading to an inflammatory response that is marked by eosinophilia, a higher than normal number of eosinophils in the blood or cerebrospinal fluid. This condition can mimic other infections affecting the central nervous system but is distinct due to the eosinophils and the specific symptomatology associated with this parasite.

The other parasites listed do not typically cause eosinophilic meningoencephalitis. For instance, Necator americanus and Ancylostoma braziliense are hookworms that primarily cause gastrointestinal symptoms and anemia, while Strongyloides stercoralis is associated with strongyloidiasis and may lead to other complications but not typically eosinophilic meningoencephalitis. Thus, Angiostrongylus cantonensis is the correct choice in