psittacosis

an endemic infection of birds, especially parrots, budgerigars, canaries, finches, pigeons, and poultry, caused by a small intracellular bacterium, Chlamydia psittaci. The birds are often asymptomatic carriers. The infection is transmitted to humans by inhalation from handling the birds or by contact with feathers, faeces, or cage dust, but person-to-person transmission also occurs. The symptoms include fever, dry cough, severe muscle pain, and headache; occasionally a severe generalized systemic illness results. The condition responds to tetracycline or erythromycin.