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psittacosis psit·ta·co·sis (sĭt'ə-kō'sĭs)
An infectious disease of parrots and related birds caused by the bacterium Chlamydia psittaci, that is communicable to humans, in whom it produces high fever, severe headache, and symptoms similar to pneumonia. Also called parrot fever.
infectious disease of worldwide distribution caused by a bacterial parasite (Chlamydia psittaci) and transmitted to humans from various birds. The infection has been found in about 70 different species of birds; parrots and parakeets (Psittacidae, from which the disease is named), pigeons, turkeys, ducks, and geese are the principal sources of human infection.