psittacosis (sĭtəkōˈsĭs) [key] or parrot fever, infectious disease caused by the species of Chlamydia psittaci and transmitted to people by birds, particularly parrots, parakeets, and lovebirds. In birds the disease takes the form of an intestinal infection, but in people the illness runs the course of a virus pneumonia; infection follows inhalation of dust from feathers or cage contents or the bite of an infected bird. Human psittacosis, which can be transmitted to others by cough droplets and sputum, is treated the same as pneumonia. The mortality rate may run as high as 30%. Restrictions on bird importation and attention to infected flocks of pigeons have been used to control the disease. Treatment with tetracycline antibiotic is usually effective.