Parrot fever is a rare infection caused by Chlamydia psittaci, a specific type of bacteria. The infection is also known as parrot disease and psittacosis. According to the Centers for Disease Control and Prevention (CDC), the United States has seen fewer than 10 human cases of parrot fever each year since 2010. However, many cases may be undiagnosed or unreported because the symptoms are similar to those of other illnesses.
As the name suggests, the disease is acquired from birds. Parrots are not the only possible culprits, however. Other wild and pet birds may also carry the infection and pass it to humans.
Parrot fever has been reported in countries including Argentina, Australia, and England. It may be found anywhere birds are kept as pets or in large confined populations (such as poultry farms). It’s more common in tropical environments.
In most cases, humans catch parrot fever from birds, including:
You can catch parrot fever by handling an infected bird or breathing in fine particles of its urine, feces, or other bodily excretions. You may also become infected if the bird bites you or "kisses" you by touching its beak to your mouth.
Catching the disease from an infected person is also possible, but very rare. This may occur when you inhale the fine droplets that are sprayed into the air when the sick person coughs.
Infected birds don’t necessarily show symptoms. They can also carry the bacteria for months before any outward signs appear. Just because a bird does not look or act sick does not mean that it’s not infected.
Infected birds may shiver or have difficulty breathing. Other symptoms include:
- discharge from the eyes or nose
- discolored droppings (urine or feces) in various shades of green
- weight loss
- lethargy and sleepiness
The sick bird may eat less or even stop eating completely.
In people, this disease typically resembles the flu or pneumonia. Symptoms usually begin approximately 10 days after exposure, but they may take as few as four days or as many as 19 days to show up.
Parrot fever has many of the symptoms that you might associate with the flu, including:
- fever and chills
- nausea and vomiting
- muscle and joint pain
- cough (typically dry)
Other possible symptoms, which may not seem flu-like, include chest pain, shortness of breath, and sensitivity to light.
In rare cases, the disease may cause inflammation of various internal organs. These include the brain, liver, and parts of the heart. It can also lead to decreased lung function and pneumonia.
Diseases that have symptoms similar to parrot fever include:
- brucellosis, a bacterial infection that is normally found in livestock but can be transmitted to humans
- tularemia, a rare disease (typically found in rabbits and rodents) that can be transmitted to humans via a tick bite, an infected fly, or contact with the infected small mammal itself
- infective endocarditis
- Q fever, another type of bacterial infection
Since parrot fever is such a rare condition, your doctor may not suspect this disease at first. Be sure to tell your doctor if you have recently been exposed to any potentially sick birds or if you work in a pet shop, veterinarian’s office, poultry-processing plant, or any other workplace that puts you in contact with birds.
To diagnose parrot fever, your doctor will generally perform several tests. Blood and sputum cultures can reveal whether you have the type of bacteria that causes this infection. A chest X-ray can show the pneumonia that is sometimes caused by the disease.
Your doctor will order an antibody titer test to see if you have antibodies to the bacteria that causes parrot fever. Antibodies are proteins that the immune system produces when it detects a foreign, harmful substance (antigen) such as bacteria or a parasite. Changes in the level of antibodies can indicate that you have been infected with the bacteria that causes parrot fever.
Parrot fever is treated with antibiotics. Tetracycline and doxycycline are two antibiotics that are effective against this disease. However, your doctor may sometimes choose to treat you with other types or classes of antibiotics. Very young children may be treated with azithromycin.
After diagnosis, antibiotic treatment typically continues for 10 to 14 days after the fever resolves.
Most people who are treated for parrot fever make a full recovery. However, recovery may be slow in people who are older, very young, or who have other health issues. Still, parrot fever rarely causes death in humans who have received proper treatment.
If you have pet birds, you can take steps to reduce your chances of getting parrot fever. These include cleaning your birdcages every day and taking good care of your birds to help prevent them from getting sick. Feed your birds properly and give them enough space so they’re not crowded together in the cage. If you have more than one cage, make sure the cages are far apart so that feces and other matter can’t be transferred between them.
The following are other steps you can take to prevent parrot fever.
If you acquire a new bird, have it looked at by a veterinarian. It’s good to then isolate the bird and monitor it for sickness for at least 30 days before you allow it to contact other birds.
If you see a sick or dead bird (whether it’s wild or a pet), you should not touch it. Contact your city’s animal control service to remove a dead wild bird. If it’s a pet, you should use caution when touching or moving it. Use gloves and a mask to avoid breathing in any bacteria, feather dust, or other debris. You should also disinfect the cage and all equipment the bird has used to prevent infection or reinfection.
Late in the year of 1929, Simon S. Martin of Baltimore purchased a parrot for his wife as a Christmas gift. He asked relatives to care for it until Christmas day. The parrot looked increasingly ill as time passed. By Christmas day, the bird was dead. Soon after, two relatives who cared for the birds became ill. Lillian, Martin’s wife, also became ill. Their doctor had recently read about parrot fever and suspected it was the cause. When the doctor asked the U.S. Public Health service for medication to treat it, he was told that there was no known treatment.
The case was featured in a newspaper, and the fear of parrot fever spread rapidly. The overall number of cases also increased dramatically. This is because doctors began to look for pet birds in the homes and businesses of people with symptoms resembling flu or pneumonia. The American media created a panic about this new mysterious illness, and inaccurate reports of the number of related fatalities only increased this panic. However, the heightened awareness of parrot fever also presented scientists with enough subjects to eventually isolate the germ and find a treatment for it.
Written by: Gretchen Holm and Diana Wells
Medically reviewed on Nov 10, 2016 by Katie Mena, MD