Alternative Names: Ornithosis; Chlamydia psittaci

Causes, incidence, and risk factors:

Psittacosis is caused by Chlamydia psittaci, a bacterium found in the droppings of birds. It is a rare disease-- fewer than 50 cases have been reported in the U.S. in the past 5 years.

Bird owners, pet shop employees, workers in poultry processing plants, and veterinarians are at increased risk for acquiring this infection.

Symptoms:

• Fever and chills
• Muscle aches
• Headache
• Fatigue
• Dry cough
• Shortness of breath
• Rales may be present
• Blood-tinged sputum

Signs and tests:

Abnormal lung sounds such as rales and decreased breath sounds are heard when listening to the chest with a stethoscope.

Tests include:

• X-ray of the chest (interstitial infiltrates)
• CT scan of the chest
• Blood gas (decreased oxygen saturation)
• Sputum culture
• Blood culture (grows chlamydia)
• Antibody titer

Treatment:

The infection is treated with antibiotics, including:

• Tetracycline
• Doxycycline
• Erythromycin
• Azithromycin

Note: Oral tetracycline is usually not prescribed for children until after all the permanent teeth have erupted. It can permanently discolor teeth that are still forming.

Support Groups:

Expectations (prognosis):

Full recovery is expected.

Complications:

• Decreased pulmonary function as a result of the pneumonia
• Heart valve infection
• Hepatitis (inflammation of the liver)
• Brain involvement

Calling your health care provider:

Antibiotics are needed to treat this infection. If you develop symptoms suggestive of psittacosis, call your health care provider.

Prevention:

Avoid exposure to suspect birds (often imported parakeets and similar birds carry this bacterium). Treat underlying medical problems that cause immune dysfunction and increase susceptibility to this disease.