1. An atypical pneumonia caused by a rickettsia microorganism and transmitted to humans from infected birds.
2. Infectious disease of birds; SYN. parrot disease, parrot fever.
Infectious acute or chronic disease, contracted by humans from birds (especially parrots), which produces pneumonialike symptoms. It is caused by a bacterium (Chlamydia psittaci, see chlamydia) and treated with tetracycline.