Psittacosis is an uncommon infectious disease that is most often transmitted to humans through exposure to infected birds, especially parrots, cockatiels, parakeets and similar pet birds. Psittacosis can affect the lungs and may cause inflammatory illness of the lungs (pneumonia). Additional common symptoms include fever, muscle pain (myalgia), headaches, and a dry cough.
Psittacosis is caused by infection with the bacterium, Chlamydia psittaci, and may also be known as ornithosis. It is rare among humans. People who own birds as pets are most likely to be affected by psittacosis. In addition, psittacosis may affect people who work in environments with birds that may be carriers of the infection such as pet store workers, farmers, veterinarians and ranchers.