Psittacosis (also known as ornithosis) is a disease caused by the bacterium Chlamydia psittaci, carried by birds. Humans most commonly catch the disease by inhaling dust containing feathers, secretions and droppings from infected birds. Older people generally experience more severe illness. This disease can be treated with antibiotics.

Last updated: 31 January 2024

What is psittacosis?

Psittacosis is an uncommon disease that is usually transmitted to humans from birds. It is caused by a bacterium called Chlamydia psittaci.

What are the symptoms?

The time from between human exposure to the bacteria and the development of symptoms varies from about five days to 4 weeks, but commonly 10 days.

People with psittacosis often develop:

  • headache
  • fever
  • chills
  • weakness
  • muscle aches
  • a dry cough
  • chest pain
  • breathless

In severe cases, pneumonia develops. Rare complications may include encephalitis (inflamation of the brain), or myocarditis (inflamation of the heart muscle).

How is it spread?

Infection usually occurs when a person inhales the bacteria, usually from dried droppings and mucous and feather dust from infected birds. People can also become infected by mouth-to-beak contact (kissing) with birds or by handling the feathers or tissues of infected birds.

Case reports suggest transmission may occur from contact with infected aborted material, abnormal equine placentas or symptomatic foals. Psittacosis can be spread from person to person or from other animals to humans but this happens very rarely.

All birds are susceptible to infection, but pet birds (for example: budgies, lorikeets and cockatiels) are most frequently involved in passing the infection to humans. Human cases associated with commercial poultry flocks are very rare in Australia and usually occur in poultry workers. Contact with wild birds and their droppings can also cause infection. Outbreaks have been linked to breathing in dust stirred up by lawn mowers after being contaminated by wild bird droppings.

Who is at risk?

People most at risk of infection with psittacosis include bird owners and/or breeders, pet shop employees, and persons whose occupation places them at risk for exposure (e.g. employees in poultry slaughtering and processing plants, veterinarians, veterinary technicians, laboratory workers, workers in avian quarantine stations, taxidermists, farmers, wildlife rehabilitators and zoo workers). Lawn mowing and gardening have also been associated with psittacosis during outbreaks.

How is it prevented?

Birds may carry the infection without signs of illness, however the infection can also be fatal to birds. Sick birds may have signs such as:

  • diarrhoea
  • weakness
  • ruffled feathers
  • poor feeding
  • runny eyes or nose.

If in doubt, a vet should examine your bird. Infected birds respond to treatment in many instances but need to be isolated and placed on long course of antibiotic treatment and have their cages disinfected. Appropriate disinfectants include those with any of the following active ingredients:

  • quaternary ammonium compounds (QACs) such as benzalkonium chloride
  • 3% hydrogen peroxide
  • alcoholic iodine solutions
  • 70% ethanol, or
  • a hospital grade disinfectant based on sodium hypochlorite. A 1:100 dilution (10mL/L) should be prepared immediately before use, and discarded at the end of each disinfection session.

Many disinfectants are respiratory irritants and should be used in a well-ventilated area. Avoid mixing disinfectants with any other product. Because birds can carry the organism without showing clinical signs it can be difficult to tell if a bird is infected, so to be safe:

  • only purchase birds from a licensed pet store or breeder.
  • wash your hands with soap and running water for 10 seconds before and after handling pet birds.
  • avoid kissing pet birds (mouth-to beak contact with).
  • house birds in clean cages of ample size that are lined with newspaper that is changed frequently.
  • do not allow droppings in cages to build up, dry up or become airborne.
  • wear a P2 respirator (available from pharmacies and hardware or other stores), and gloves and dampen any bird droppings or cages, before cleaning the case.
  • wash your hands after cleaning the cage.
  • take sick birds to a veterinarian as soon as possible.
  • wear a P2 respirator, gloves, disposable cap and protective clothing when dealing with infected birds. Instructions on how to properly fit a P2 respirator.

People dealing with aborted horse material should follow the advice in Primefact: biosecurity advice when handling aborted material from horses.

For simple steps on how to protect yourself from wildlife to prevent infection, and organisations to report sick, injured or dead wildlife, please see Be careful around wildlife factsheet.

How is it diagnosed?

Your doctor can diagnose psittacosis by the symptoms, an examination and by doing some tests. Tests may include a chest x-ray, and taking some blood or respiratory samples to test for the bacteria.

How is it treated?

Psittacosis is treated with antibiotics for a period of up to two weeks.

What is the public health response?

Laboratories must confidentially notify cases of psittacosis to the local public health unit. Public health unit staff will talk to the treating doctor and patient or carer to identify where the infection may have come from. Other people who may have been exposed to an infected bird should be made aware of the symptoms of infection. The bird should be treated and its environment cleaned with disinfectant to prevent further infections being spread to other people or other birds.

For further information please call your local Public Health Unit on 1300 066 055.

Current as at: Wednesday 31 January 2024
Contact page owner: One Health