(ornithosis, parrot fever)
Psittacosis is a disease caused by a microorganism called Chlamydia psittaci. It is usually transmitted to humans from birds, especially parakeets and parrots, but also from species like pigeons, turkeys, and ducks.
Since this disease is spread by birds, it occasionally occurs in pet store workers or people who have recently purchased an infected pet bird. It may also be found in farmers and slaughterhouse workers who process turkeys and ducks.
How do people get psittacosis?
The bacteria can infect people exposed to infected birds. It is important to know that infected birds do not always show signs of disease or seem sick. Both sick birds and birds without signs of illness shed the bacteria in their droppings and respiratory secretions. When the droppings and secretions dry, small dust particles (including the bacteria) can get into the air. The most common way someone gets infected is by breathing in the dust from these dried secretions. Less commonly, birds infect people through bites and beak-to-mouth contact.
In general, people do not spread psittacosis to other people. However, this is possible in rare cases. There is no evidence that the bacteria spread by preparing or eating chicken meat.
People at Increased Risk
People of all ages can get psittacosis, but it is more commonly reported among adults. Those who have contact with pet birds and poultry, including people who work in bird-related occupations, are at increased risk:
- Bird owners
- Aviary and pet shop employees
- Poultry workers
Signs and Symptoms
In general, psittacosis causes mild illness. The most common symptoms include:
- Fever and chills
- Muscle aches
- Dry cough
Psittacosis can also cause pneumonia, a lung infection, which may require care in a hospital. Rarely, psittacosis can result in death.
Most people begin developing signs and symptoms within 5 to 14 days after exposure to the bacteria (Chlamydia psittaci). Less commonly, people report symptoms starting after 14 days.
The signs of C. psittaci infection in birds are non-specific and include:
- Poor appetite
- Inflamed eyes
- Breathing difficulty
Infected birds may not have signs of disease or seem sick. When birds have symptoms caused by C. psittaci infection, veterinarians call the disease avian chlamydiosis.
Diagnosis and Treatment
Symptoms of psittacosis are similar to many other respiratory illnesses. In addition, tests to detect the bacteria directly may not be readily available. For these reasons, clinicians may not suspect it, making psittacosis difficult to diagnose. The Centers for Disease Control and Prevention (CDC) rarely receives reports of psittacosis. Tell your clinician if you get sick after buying or handling a pet bird or poultry.
Clinicians can use a number of tests to determine if someone has psittacosis. These tests include collecting sputum (phlegm), blood or swabs from the nose and/or throat to detect the bacteria.
People diagnosed with psittacosis usually take antibiotics to treat the infection. Most people improve quickly if they start antibiotics soon after they first get sick.
Most people treated properly for psittacosis make a full recovery. However, some people have serious complications and need care in a hospital. Complications include:
- Serious pneumonia (lung infection)
- Endocarditis (inflammation of the heart valves)
- Hepatitis (inflammation of the liver)
- Inflammation of the nerves or the brain, leading to neurologic problems
With appropriate antibiotic treatment, psittacosis rarely (less than 1 in 100 cases) results in death.
While there is no vaccine to prevent psittacosis, there are things you can do to protect yourself and others. Buy pet birds only from a well-known pet store. If you own pet birds or poultry, follow good precautions when handling and cleaning birds and cages.
This is a Wisconsin disease surveillance category II disease:
- Report to the patient's local public health department electronically, through the Wisconsin Electronic Disease Surveillance System (WEDSS), by mail or fax using an Acute and Communicable Disease case report, F-441 51(Word) or by other means within 72 hours upon recognition of a case.
- Information on communicable disease reporting
Wisconsin case reporting and public health follow-up guidelines: