Enteric diseases.

This paper focuses on the growing incidence of the "new" sexually transmitted parasitic enteric diseases: amebiasis and giardiasis. Two major behavioral factors influence transmission of these diseases in the gay community: 1) oral-rectal and oral-genital sexual contact and 2) multiple sexual partners. Pathogenesis, clinical signs and symptoms and complications associated with these diseases are also discussed. Although many patients present with severe symptoms, approximately 50 percent of infected patients are asymptomatic. The diagnostic procedures include a fresh purged stool examination, nonpurged warm stool examinations, and/or cold stool specimens. The serologic tests (serum precipitin and hemagglutination) are of value only in severely symptomatic invasive disease. Different treatment regimens and their side effects are discussed. Drugs used in the treatment of the enteric diseases include diiodohydroxyquin, metronidazole, furamide, and paromomycin. Only 60 to 70 percent of patients with the disease are cured, and 30 to 40 percent of patients require multiple courses of therapy. Test-of-cure examinations, ideally consisting of one or two purged stool specimens, are necessary in follow-up management.