Intermittent cutaneous migratory swellings were the commonest manifestation. Larvae were identified in 26 cases, while in 72, final diagnosis was made on the basis of epidemiologic data, food habits, and positive enzyme-linked immunosorbent assay and Western blot results. Gnathostomosis is a foodborne zoonotic disease caused by several species of nematode Gnathostoma .
Freshwater fish eating cyclops are the second intermediate host.
Consumption of this fish by cats, dogs, or other mammals results in development of adults in the gut, closing the cycle. Humans acquire the infection by consuming raw or undercooked freshwater fish. When a larva is ingested by a human host, no further development occurs, but the larva migrates through subcutaneous tissue and internal organs where it produces migratory swelling in the skin and other symptoms depending on the site or organ affected. The parasites may have spread when new dams built on rivers of the Pacific Ocean coast were unnoticeably seeded with infected fish. A standardized questionnaire was administered to each patient, requesting demographic data, medical history, clinical features, age, occupation, years of residence at the city, and food habits.