Animals Involved
Dogs, cats, swine, wild carnivores, opossums, and other mammals are definitive hosts; snails and freshwater crustaceans are intermediate hosts; wild boars, sheep, goats, rabbits, birds, other animals are paratenic hosts
Known Distributions
Flukes are worldwide (distribution varies with species); most human infections in Asia, Africa, tropical America
Probable Means of Spreading
Ingestion of undercooked, infected freshwater crustaceans (crabs, crayfish); metacercariae on contaminated hands, fomites after preparing crustaceans, or undercooked meat from paratenic hosts such as wild boars
Clinical Manifestations in People
Chills, fever possible during migration to lungs; pulmonary disease resembling tuberculosis with cough, bloodtinged sputum; abdominal form with dull pain, tenderness, possibly diarrhea; less often, neurologic signs, migratory skin nodules, other organspecific symptoms; predominant signs vary with species of fluke