psittacosis /sit′əkō″sis/ [Gk, psittakos, parrot] , an infectious illness caused by the bacterium Chlamydia psittaci, characterized by respiratory pneumonia-like symptoms and transmitted to humans inhaling dried secretions from infected birds, especially pet birds and poultry. The clinical manifestations of the disease are extremely variable and resemble those of a great number of infectious diseases, but fever, cough, anorexia, and severe headache are almost always present. All chlamydiae are difficult to isolate and culture, but a history of exposure to birds is highly suggestive. A demonstrated rise in antibody titer confirms a diagnosis. Tetracycline is usually used to treat psittacosis and is continued for 10 to 14 days after the fever subsides. Isolation is advised. Also called ornithosis, parrot fever. See also Chlamydia.
