Psittacosis (Ornithosis; Chlamydia psittaci)

Clinical Summary

• Psittacosis is a zoonotic bacterial respiratory illness caused by Chlamydia psittaci, which commonly infects birds. Clinical disease in people most often presents as an upper respiratory tract infection and can progress to pneumonia.
• Exposure history is key. Human infection is most commonly associated with pet birds (e.g., parrots/cockatiels) and poultry (e.g., turkeys/chickens/ducks), usually from inhaling dust/aerosols from dried droppings or respiratory secretions.
• Symptoms can include fever, headache, and dry cough, and disease severity can vary. Maintain suspicion in compatible febrile respiratory illness with bird exposure and initiate treatment promptly.
• Diagnosis can be challenging. CDC outlines multiple testing options (e.g., serology and molecular methods), and notes culture is limited to specialized reference labs and is not optimal for rapid treatment decisions.
• Treatment: CDC emphasizes prompt antibiotic treatment to increase chances of quick recovery (doxycycline is commonly used per standard guidance). Psittacosis is a reportable condition in Tennessee.

Clinical Info & Links

What Is It

Psittacosis (also called ornithosis or “parrot fever”) is a respiratory illness caused by the bacteria Chlamydia psittaci, which more commonly infects birds.

Who Is at Higher Risk

Anyone can get psittacosis, but the risk is higher for people who have contact with pet birds or poultry, including bird owners and people who work with birds (for example, in pet shops, aviaries, poultry operations, or veterinary settings).

Signs and Symptoms

Psittacosis can cause a range of symptoms, commonly including fever, headache, and a dry cough. Some people can develop more serious respiratory illnesses, including pneumonia.

How It Spreads

People most often get infected by breathing in dust that contains the bacteria from dried bird droppings or respiratory secretions. Both sick birds and birds without obvious signs of illness can shed the bacteria.

Prevention

Risk can be reduced by using safe bird-handling and cleaning practices (especially when cleaning cages or areas with droppings) and following prevention guidance for bird owners and bird-related workplaces.