Human intestinal nematodiasis in the United States.

Human intestinal nematodes, all of which can be acquired in the continental United States, can cause a variety of ills including iron deficiency anemia, surgical emergencies, eosinophilic pneumonia, malabsorption, dysentery, myositis, and death. The severity of illness is related to the number of parasites acquired exogenously or the ability of the parasite to multiply within the host. Diagnosis of clinically significant infection can usually be made by stool examination, and appropriate treatment requires an understanding of the life-span and pathogenic potential of the parasite.