Technical Information
Technical information is taken directly from the December 2002 CDC Division of Bacterial and Mycotic Diseases: Psittacosis

This direct FA stained mouse brain impression smear reveals the presence of the bacterium Chlamydia psittaci (1971)

Clinical Features
In humans, fever, chills, headache, muscle aches, and a dry cough. Pneumonia is often evident on chest x-ray.

Etiologic Agent
Chlamydia psittaci, a bacterium.

Incidence
Since 1996, fewer than 50 confirmed cases were reported in the United States each year. Many more cases may occur that are not correctly diagnosed or reported.

Sequelae
Enlargement of the endocardium within the heart, hepatitis, and neurological complications may occasionally occur. Severe pneumonia requiring intensive-care support may also occur. Fatal cases have been reported.

Transmission
Infection is acquired by inhaling dried secretions from infected birds. The incubation period is 6 to 19 days. Although all birds are susceptible, pet birds (parrots, parakeets, macaws, and cockatiels) and poultry (turkeys and ducks) are most frequently involved in transmission to humans.

Risk Groups
Bird owners, pet shop employees, and veterinarians. Outbreaks of psittacosis in poultry processing plants have been reported.

Surveillance
Psittacosis is a reportable condition in most states.

Challenges
Diagnosis of psittacosis can be difficult. Infected birds often do not demonstrate symtoms. Trace backs of infected birds to distributors and breeders often is not possible because of limited regulation of the pet bird industry.

Opportunities
Characterize new and rapid diagnostic tests for human and avian psittacosis, and determine value of screening flocks for avian psittacosis to prevent human infection.