Psittacosis

Definition

Psittacosis is an infection caused by Chlamydia psittaci, a type of bacteria found in the droppings of birds. Birds spread the infection to humans.

Alternative Names

Ornithosis; Chlamydia psittaci

Causes, incidence, and risk factors

Psittacosis is a rare disease-- 100 to 200 cases are reported each year in the United States.

Bird owners, pet shop employees, persons who work in poultry processing plants, and veterinarians are at increased risk for this infection. Typical birds involved are parrots, parakeets, and budgerigars, although other birds have also caused the disease.

Symptoms

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

Signs and tests

The health care provider will hear abnormal lung sounds such as crackles and decreased breath sounds when listening to the chest with a stethoscope.

Tests include:

• Antibody titer (rising titer over time is a sign of infection)
• Blood culture (grows chlamydia)
• Blood gases
• CT scan of the chest
• Sputum culture
• X-ray of the chest

Treatment

The infection is treated with antibiotics. Doxycycline is the first line treatment. Other antibiotics that may be prescribed include:

• Azithromycin
• Erythromycin
• Rifampin
• Tetracycline

Note: Tetracycline by mouth is usually not prescribed for children until after all their permanent teeth have started to grow in. The medicine can permanently discolor teeth that are still forming.

Expectations (prognosis)

Full recovery is expected.

Complications

• Brain involvement
• Decreased lung function as a result of the pneumonia
• Heart valve infection
• Inflammation of the liver (hepatitis)

Calling your health care provider

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

Prevention

Avoid exposure to birds that may carry this bacteria, such as imported parakeets. Medical problems that lead to a weak immune system increase your risk for this disease and should be treated appropriately.

References

Brunham RC. Diseases caused by chlamydiae. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 339.