Psittacosis
Psittacosis is a disease caused by the bacteria Chlamydia psittaci, which is usually transmitted to humans from birds in the parrot (psittacine) family. The bacteria are also found in other species including poultry, pigeons, canaries and sea birds, and more rarely in horses and other livestock. The disease is usually mild, however in some people, particularly the elderly, it can produce severe illness.
Signs and symptoms
Psittacosis tends to produce a non-specific illness. Symptoms can be mild or moderate and may include fever, headache, rash, muscle aches, chills and non-productive cough with pneumonia. Occasionally more serious complications affecting the heart, liver or lungs may occur.
Most symptoms improve quickly with appropriate antibiotic treatment.
Transmission
The bacteria can be found in dried droppings, secretions and dust from feathers of infected birds. Humans can be infected by inhaling infected discharges or dust. The bacteria may survive in dust for several months. Infected birds may have no obvious symptoms. Human to human transmission is rare, but has occurred via airborne exposure.
There is evidence of occasional transmission from birds to horses and other livestock, potentially causing respiratory disease and fetal abortion in pregnant mares. Airborne or mucous membrane exposure after direct contact with the aborted fetus or placental membranes of an infected horse has been known to rarely cause psittacosis in humans.
The time from contact with the bacteria and the development of symptoms is usually from 5 days to four weeks. Re-infection can occur if cleaning of cages and aviaries is not maintained.
Treatment
Psittacosis is usually treated with antibiotics.
Prevention
There is no vaccine for protection against psittacosis.
Educating people about the disease, and the importance of maintaining a clean living environment for pet birds will assist in preventing the disease. Personal protective equipment (including P2 masks and gloves) should be worn when cleaning the cages of birds and by veterinarians and vet students attending abortions/stillbirths or examining aborted fetuses from horses or other livestock
Control
In addition to treating infected people, treat infected birds with antibiotics and ensure that the environment in which they live is thoroughly cleaned and disinfected to reduce the spread of the disease to other birds and people. Masks and gloves should be discarded and clothes and equipment disinfected following use.
Recommended disinfectants include benzalkonium chloride, 3% hydrogen peroxide, alcoholic iodine solutions, 70% ethanol and hospital grade disinfectants based on sodium hypochlorite at a 1:100 dilution.
Help and assistance
For further information, please contact your local doctor, community health centre or nearest public health unit.
Footnotes
Psittacosis (Ornithosis) CDNA National Guidelines for Public Health Units. Available at: http://www.health.gov.au/internet/main/publishing.nsf/Content/cdna-song-psittacosis.htm
Chan, J., Doyle, B. Branley, J., Sheppeard, V., Gabor, M., Viney, K. Quinn, H., Janover, O. McCready, M., and Heller, J. (2017). An outbreak of psittacosis at a veterinary school demonstrating a novel source of infection.OneHealth 3: 29-33
Heymann, D., ed. 2015 . Control of Communicable Diseases Manual, 20th edition. Washington, DC: American Public Health Association. 491-4