Psittacosis is a bacterial lung infection you catch from birds. It’s caused by Chlamydia psittaci, a bacterium that lives inside the cells of infected birds and spreads to humans primarily through inhaling contaminated dust. Sometimes called “parrot fever,” the disease is uncommon in the United States, with fewer than 10 confirmed cases reported to the CDC in a typical year, though experts believe it is significantly underdiagnosed.
How the Infection Spreads
The bacterium lives in the droppings, urine, and respiratory secretions of infected birds. When those secretions dry out, tiny dust particles containing the bacteria become airborne. Breathing in that contaminated dust is the most common way humans get infected. You don’t need to touch the bird directly. Simply cleaning a cage, sweeping an area where birds have been, or spending time in a space with dried droppings can be enough exposure.
Importantly, birds can carry and shed C. psittaci without looking sick. A bird that appears perfectly healthy can still release the bacterium in its droppings and respiratory secretions, which makes it difficult to judge risk based on a bird’s appearance alone. The disease has been linked to parrots, cockatiels, and other pet birds in the parrot family, but poultry, pigeons, and other non-parrot species can also carry the bacterium. A 2018 outbreak among poultry plant workers in the U.S. resulted in 13 confirmed cases.
Person-to-person transmission is extremely rare. This is overwhelmingly a bird-to-human disease.
Who Is Most at Risk
People who have close, regular contact with birds face the highest risk. That includes pet bird owners, bird breeders, veterinary staff, pet store employees, and workers in poultry processing plants. Even brief, indirect exposure can occasionally cause infection if the environment is heavily contaminated.
Symptoms and How It Progresses
Psittacosis typically begins 5 to 14 days after exposure. The illness often starts suddenly with fever, chills, headache, and muscle aches, resembling a bad case of the flu. A dry cough usually develops and can progress to pneumonia. Headache is frequently described as one of the most prominent symptoms, sometimes severe.
The disease ranges widely in severity. Some people experience a mild illness they might mistake for a common respiratory infection. Others develop a serious pneumonia requiring hospitalization. Without treatment, the infection can spread beyond the lungs and affect the liver, heart, and other organs. Endocarditis (infection of the heart valves) and hepatitis are among the more serious complications, though these are rare. With appropriate antibiotic treatment, fatal cases are very uncommon.
How It Is Diagnosed
Diagnosing psittacosis can be tricky because its symptoms overlap with many other respiratory infections. The key clue for doctors is often a history of bird exposure. If you develop pneumonia-like symptoms and you own birds, work with birds, or recently visited a place with birds, that information is critical to share with your healthcare provider.
Laboratories can confirm the diagnosis through a few methods. Blood tests (serology) look for antibodies your immune system produces in response to the bacteria. A newer and more accurate option is PCR testing, which detects the bacterium’s genetic material directly and provides faster results. PCR is highly sensitive and specific but not yet widely available in standard clinical labs. Growing the bacterium in a lab culture is possible but time-consuming and typically performed only by specialized reference laboratories, making it impractical for guiding treatment decisions.
Because testing options are limited and the disease is uncommon, many cases are likely missed entirely or attributed to other causes. This is a major reason the CDC considers psittacosis underreported.
Treatment and Recovery
Psittacosis responds well to antibiotics. Doxycycline, a type of tetracycline antibiotic, is the standard first-line treatment. For people who can’t take doxycycline (such as pregnant women or those with allergies), alternatives like azithromycin or erythromycin are used. Treatment courses typically last 10 to 14 days, and completing the full course is important to prevent relapse.
Most people begin to feel better within a few days of starting antibiotics, though full recovery can take several weeks, particularly if pneumonia developed. Without treatment, recovery is slower and the risk of complications rises significantly.
Preventing Psittacosis if You Own Birds
Handwashing is the simplest and most effective protection. Wash your hands thoroughly with soap and running water after handling birds, touching their droppings, or cleaning anything inside their cages.
Cage cleaning habits matter more than most bird owners realize. Dry sweeping or vacuuming around bird cages can send contaminated dust into the air, which is exactly how the bacterium gets inhaled. Instead, wet surfaces and cages with water or a disinfectant before cleaning to keep dust down. Clean cages and food and water bowls daily.
If you keep multiple birds, a few additional steps reduce the risk of the bacteria spreading:
- Avoid overcrowding. Don’t stack cages on top of each other, as droppings from an upper cage can contaminate birds below.
- Use solid-sided barriers between adjacent cages to prevent cross-contamination.
- Isolate and treat any bird that tests positive or shows signs of illness, such as ruffled feathers, discharge from the eyes or nose, or changes in droppings.
- Quarantine new birds before introducing them to your existing flock.
When handling a bird you suspect is infected, wear gloves and an appropriate mask to reduce your exposure to airborne particles.
Reporting and Public Health
Psittacosis is a reportable condition in most U.S. states, meaning healthcare providers are required to notify local health authorities when they confirm a case. Between 1988 and 2010, the number of reported cases in the U.S. steadily declined. Since 2010, the CDC has typically received fewer than 10 reports per year. While those numbers sound reassuringly small, the true number of infections is almost certainly higher given how easily the disease is missed or misdiagnosed as routine pneumonia.