AIR SAC TREMATODES (CYCLOCOELIDAE STOSSICH, 1902) INFECTING BIRDS IN ZOOLOGICAL INSTITUTIONS IN THE UNITED STATES.

Air sac trematodes (Digenea: Cyclocoelidae) were detected in 23 avian species from eight aviaries in the United States. Most of the infected host species were passeriform birds, but a few species in other orders also were infected. Four species of adult flukes were encountered: Circumvitellatrema momota , Morishitium sp., Psophiatrema greineri , and Szidatitrema yamagutii . Findings from retrospective review of medical records, necropsy records, and author observations are presented. Potential terrestrial snail intermediate hosts were collected from three indoor aviaries. A high prevalence (47%) of larval trematode infections was demonstrated in one species of nonnative snail ( Prosopeas achatinacea ); one larva was isolated and matched to the adult species ( C. momota ) from birds using PCR. Problems with introducing potentially infected wild-caught birds into aviaries, and exchanging captive individuals between aviaries where they potentially may carry infections, are discussed.