Psittacosis Psittacosis Psittacosis—also known as parrot fever, and ornithosis—is a zoonotic infectious disease caused by a bacterium called "Chlamydophila psittaci" and contracted from infected parrots, such as macaws, cockatiels, and budgerigars, and pigeons, sparrows, ducks, hens, gulls and many other species of birds. The incidence of infection in canaries and finches is believed to be lower than in psittacine birds. In certain contexts, the word is used when the disease is carried by any species of birds belonging to the family Psittacidae, whereas "ornithosis" is used when other birds carry the disease. In humans, after an incubation period of 5–19 days,
Psittacosis cases may occur that are not correctly diagnosed or reported. Bird owners, pet shop employees, zookeepers, and veterinarians are at risk of the infection. Some outbreaks of psittacosis in poultry-processing plants have been reported. In birds, "Chlamydia psittaci" infection is referred to as avian chlamydiosis. Infected birds shed the bacteria through feces and nasal discharges, which can remain infectious for several months. Many strains remain quiescent in birds until activated under stress. Birds are excellent, highly mobile vectors for the distribution of chlamydial infection because they feed on, and have access to, the detritus of infected animals of all sorts.