Helminthic Infections

Helminthic parasites are multicellular worms that possess differentiated organ systems. They (with a few exceptions) do not replicate in the human host, and they tend to elicit eosinophilia within the tissues and blood of infected humans. Helminthic parasites include nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). The major intestinal nematodes are roundworm, pinworm, hookworm, whipworm, and Strongyloides stercoralis. Trichinellosis is caused by five species of the nematode Trichinella and develops after ingestion of infected meat, usually pork or the meat of certain carnivores. Nematode infections of the major tissue are anisakiasis, visceral larva migrans,Angiostrongylus cantonensis infection, mammomonogamosis (syngamosis), gnathostomiasis, dracunculiasis, and filariasis. Trematode and cestode infections are also described in this chapter, including infections by fish, beef, and pork tapeworms, as well as cysticercosis. Disease from Paragonimus, Clonorchis, Fasciola, Fasciolopsis, and Schistosoma is covered. Echinococcus infection and hydatid cyst disease are discussed. Tables describe intestinal nematode infection and treatment and filarial parasites of hu