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ornithosis or·ni·tho·sis (ôr'nə-thō'sĭs)
A disease of birds caused by Chlamydia psittaci and contracted by humans through contact with infected birds.
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.