95 Nematode Infections

The roughly 500,00 species in the phylum Nemathel- minthes, the nematodes or roundworms, include both free-living forms and important parasites of plants and animals. Many species of nematodes parasitize humans, and several of them are major public health problems in poor countries, especially in the tropics. Some species reside as adults in the intestine; others are found in the blood and tissues. See Ascariasis, Dracunculiasis, Enterobiasis, Filaria­sis, Onchocerciasis, Strongyloidiasis, Trichinosis, and Trichuriasis.

K. David Patterson