By Margaret A. Wissman, DVM, DABVP — Avian Practice
A good understanding of chlamydiosis will help bird owners make educated choices regarding bird ownership and care.
Courtesy Lauren Falco, New York
Q: I have chronic hepatitis. Like other people with chronic diseases or who are receiving cancer treatments, my immune system is suppressed. My vet was very concerned when I told her about my impending treatments. She suggested a number of tests to run on our cockatiel to reduce the chances that I could contract a disease from it.
My doctor (a gastronenterologist) said he knew of no risks from birds. The fact that my doctor says he has never heard of any concerns leaves me wondering if there are risks he, other doctors and other patients aren't informed about.
What are the risks for immune-suppressed people who own birds? How can those risks be reduced? What are the most common diseases that people can get from birds?
A: I am sorry that you are suffering from a disease that suppresses your immune system. Having a chronic, debilitating disease is stressful enough in itself, and being uncertain whether or not your bird is threatening your health doesn't help.
Although medical doctors are trained in all aspects of human medicine, epidemiologists and infectious-disease specialists are more likely to have a thorough understanding of diseases that can be transmitted from animals to humans (called zoonotic diseases). Veterinarians also receive formal training in zoonotic diseases, and, since we deal with these as part of our day-to-day work, it makes sense that we can be of help in situations such as yours. There are also continuing education courses available to veterinarians to help them deal with the immunocompromised pet owner.
One disease that is quite common in pet birds, especially budgies and cockatiels, is chlamydiosis. This disease is also called psittacosis, ornithosis and parrot fever. It is caused by a primitive bacterium called Chlamydia psittaci. This is a different organism than the chlamydial organism responsible for the sexually transmitted disease in humans (Chlamydia trachomatis). Chlamydiosis can occur in all psittacine birds, and it has been isolated from approximately 100 species of birds. It is most commonly isolated from psittacine birds (especially budgerigars and cockatiels), but among nonpsittacine birds it is frequently isolated from pigeons, doves and mynah birds. The prevalence of infection is thought to be lower in canaries and finches than in psittacines. It can cause a bird to be seriously ill, be an asymptomatic carrier (looking and acting perfectly normal) or be in just about any condition in between. Chlamydiosis can be very difficult to diagnose in a live bird, especially cockatiels and budgies, unless they are actively shedding the organism in the droppings. The larger birds will often predictably develop an antibody titer against the organism, but the smaller birds sometimes will not. Newer testing using DNA PCR technology may detect the organism of the blood of an infected bird, or it may pick up the organism on a swab taken of the choanal slit and cloaca. But, if the tests are negative, it doesn't mean for certain that a bird doesn't have chlamydiosis. Therein lies the basic problem. It is not worth gambling with your health, even if a pet cockatiel tests negative, because it may still be harboring the organism and shedding it during times of stress.
I work with many immunosuppressed people, including geriatric people in nursing home facilities, and pet bird owners and bird breeders with AIDS and HIV. My clients also include several diabetics, a man on renal dialysis, several people undergoing radiation and chemotherapy for cancer, a woman with Lupus, several people with emphysema and others on prednisone (a powerful immunosuppressive steroid drug). These people believe their relationship with their birds enriches their lives beyond the risks involved. However, that is not to say that I act recklessly concerning the health of these fine people.
While it is important to test any birds belonging to immunosuppressed people for chlamydiosis to document any positive results, it is my opinion that regardless of the test results, it is safest to treat these birds with doxycycline for a minimum of 45 days. Testing will not catch all positive birds, so treating the birds will greatly reduce the chance that an owner will be exposed to the organism. Most birds reduce shedding of the organism after seven days of treatment.
Tips For Immunocompromised
- Have your vet test your bird for chlamydiosis.
- Keep cages clean.
- Wash your hands after handling a bird or coming into contact with dander, feathers, droppings or equipment.
- Avoid inhaling dust when cleaning cages.
- Run a quality filter in the room where birds are kept.
While this answer is not meant to be an in-depth treatise on chlamydiosis, I wanted you to know that it may be possible for you to keep your pet bird with minimal risk to your health. This will entail working closely with an avian veterinarian who is very knowledgeable about this complex disease. Treatment should consist of antibiotic therapy. Doxycycline is generally considered the drug of choice in this country; however, chlortetracycline and enrofloxacin can also be used. Treatment should only be undertaken under the close guidance of an experienced avian vet. Birds that have recovered from chlamydiosis are not immune to it and are susceptible to catching it again. Some birds cannot ever be cured, although this is a very low percentage of birds.
Chlamydia is shed in the droppings and also in respiratory secretions. It is quite stable for months in the environment. Infection usually develops when a person inhales the organism that has been aerosolized from dried feces or respiratory secretions. Other means of exposure include mouth-to-beak contact and handling infected birds' plumage and tissues. Brief exposure can lead to infection.
In humans, illness from Chlamydia usually occurs after an incubation period of approximately five to 14 days, but longer incubation periods have been reported. The severity of disease ranges from unapparent illness to systemic disease with severe pneumonia. Less than 1 percent of humans who are properly treated die as a result of chlamydial infection. Humans with symptomatic infection typically have abrupt onset of fever, chills, headache, malaise and muscle pain. A nonproductive cough may occur that may be accompanied by breathing difficulty and chest tightness. Chlamydia psittaci can also affect other organ systems and infection can result in endocarditis, myocarditis, hepatitis, arthritis, keratoconjunctivitis and encephalitis. Fetal death can result in pregnant women infected with psittacosis. Remember that exposure does not mean that disease will occur.
Diagnosis in humans can be confirmed by culturing the organism from respiratory secretions or by an increase in titer from blood samples taken at least two weeks apart. In many states, the disease is reportable to appropriate health authorities. Medical doctors should be aware that chlamydiosis is not a rare disease in pet birds.
People at risk should consider wearing protective clothing, gloves, a paper surgical cap and a respirator with an N95 rating or higher when cleaning cages or handling infected birds. Preventive husbandry is also important. Cages and bowls should be cleaned daily. Disinfection with bleach, stabilized chlorine products, quaternary ammonium compounds, alcohol, Lysol or chlorophenols should be performed weekly. (Ventilate well, and allow cages to dry before returning the birds to them.) Items that cannot be disinfected (wooden perches, nest material, litter) should be discarded.
I hope that the information I have presented does not unduly frighten bird owners. A good understanding of chlamydiosis will help bird owners make educated choices regarding bird ownership and care. If your veterinarian wants more information on chlamydiosis, I recommend "The Compendium of Chlamydiosis (psittacosis) Control," 1999, from JAVMA, Vol. 214, No. 5, March 1, 1999, pp. 640-646. "The Compendium" can also be accessed electronically at the AVMA Web site (www.avma.org) and the CDC Web site (www.cdc.gov).
There are other zoonotic diseases that can be contracted from pet birds; however, most are rare or not common in this country. Newcastle's Disease and one type of influenza may be contracted by humans from birds. A protozoal parasite called Giardia was thought not to be contagious from birds to people, but the latest information that I have received indicates that it might be transmissible from dogs and cats to humans. To be on the safe side, if your bird is diagnosed with Giardia, take all precautions to prevent contact with infective feces. Of course, this makes perfect sense anyway.
Keep cages clean, wash your hands after handling a bird or coming into contact with dander, feathers, droppings or equipment and avoid inhaling dust when cleaning cages. Run a high quality filter in the room where birds are kept. Use good judgment and common sense around your birds. People who are immunocompromised may be able to have pet or breeder birds, as long as they are able to work with an avian veterinarian who is up on zoonotic diseases and their medical doctors understand the dynamics involved.