Psittacosis: threat for birds and people
"Psittacosis" is caused by an organism called Chlamydophila psittaci, formerly known asChlamydia psittaci. This organism has characteristics of both bacteria and viruses. The disease in humans is called psittacosis, and the same term is commonly used to refer to the disease in parrots. A more exact term for the avian disease is "Avian Chlamydiosis." It is sometimes also called parrot fever. C. psittaci can infect other mammals as well.
Sign in Pet Birds
Signs of psittacosis can include any of the following: discharge from the eyes or nares, difficulty breathing, diarrhea, lethargy, decreased appetite, weight loss, weakness, and depression. The disease can be fatal. However, birds can be carriers of C. psittaci without showing any signs. Carriers may subsequently become ill if they become stressed, and they may pass the organism to their offspring which may become ill or die as young birds are more susceptible.
There is no single definitive test for Chlamydiosis, although several screening tests are available to your veterinarian. A combination of history, clinical signs, bloodwork, and tests that screen for the presence ofC. psittaci can be used for diagnosis.
The best course of treatment (medication, dose, method of administration) should be decided by your veterinarian. The disease is usually treatable, but the success of treatment depends on the overall health of the bird and the presence of other disease, as well as the age and species of the bird. Treatment is usually long term (make sure you follow the full course) and should be combined with thorough disinfection of your premises with a disinfectant recommended by your vet.
The disease can be transmitted via nasal discharge as well as feces, either by inhalation or ingestion. C. psittaci is resistant to drying so can survive for a long time in the environment and readily becomes airborne in dust particles. Shedding of C. psittaci by infected birds (including asymptomatic birds) increases in times of stress (shipping, overcrowding, environmental stress, presence of other diseases, breeding, etc.).
If possible, purchase birds from sources that pre-screen for Chlamydiosis, and have new birds screened for chlamydiosis by an avian veterinarian. If you already have birds at home, quarantine new birds for at least 6 weeks. If one of your birds is diagnosed with Chlamydiosis, that bird must be isolated from other birds (preferably in a different building as the disease can be easily transmitted by airborne particles) and any other birds that show signs should be immediately isolated as well.
Precautions If Your Bird has Chlamydiosis
Since the disease can be passed to people (i.e. is zoonotic), if your pet bird is diagnosed with Chlamydiosis, the following precautions should be taken:
- Thoroughly disinfect your premises and all of the bird's belongings.
- Exercise caution in the handling of bird droppings.
- Keep circulation of feathers and dust to a minimum.
- Do not allow elderly, pregnant, sick or very young people to have contact with your bird.
- Reduce stress in the bird's environment.
Signs in Humans
In people, signs generally appear 4-15 days after exposure may include sudden onset of fever, chills, headache, malaise, and muscle pain, nonproductive cough, and sometimes breathing difficulty and chest tightness. C. psittaci infection can result in pneumonia, sometimes severe. Rarely, other organs may be involved, and fatal cases have been reported.
Who is At Risk?
The CDC estimates that 70% of cases in people result from contact with companion birds. Psittacosis may be under diagnosed, but it is not a common disease in humans. Psittacosis is usually quite mild and easily treatable with antibiotics, but can be fatal, so if you have symptoms of psittacosis and have had contact with a bird, be sure to tell your physician. Immunocompromised people, the elderly, and young children are at increased risk of serious disease and complications.