Avian Chlamydophilosis and Psittacosis

Many caged and wild birds carry Chlamydophila psittaci (used to be called Chlamydia psittaci) and yet appear to be healthy. Others develop signs of disease that can include conjunctivitis, sneezing, nasal discharge, pneumonia and air sac disease, diarrhoea and liver disease.

Human infection can be acquired by inhaling dusty droppings or droplets in the air from the bird sneezing or from using high pressure hoses to clean cages and aviaries or from doing necropsies (post mortems) without appropriate protection with mask, gloves etc.. Bird chlamydiosis in people can range from a very mild to life-threatening disease. Fever, flu-like symptoms, sore eyes, chest, liver and brain signs may develop. It is most severe in immunocompromised people, such as those with AIDS and those receiving chemotherapy for cancer etc or those on high doses of corticosteroid drugs.

Ask your doctor about this disease if you "get sick" and need help.

The term "psittacosis" refers to the disease chlamydophilosis when it affects or is acquired from psittacine birds. The corresponding term for chlamydophilosis affecting or acquired from non- psittacine birds such as pigeons is "ornithosis".

However, these days " chlamydophilosis " or "avian chlamydophilosis " are probably preferred terms. Other lay terms are "bird fever" and "parrot fever". All these terms basically refer to the same disease. Avian chlamydophilosis is the disease of birds associated with infection with the organism "Chlamydophila psittaci". This organism is usually smaller than most bacteria and bigger than most viruses. It is just visible under oil immersion high magnification using a light microscope if it is specially stained. It has a complex life cycle and often re- combines genetically with other strains of the organisms to form new strains. Such strains can vary in their probability of being associated with disease in different species of birds. For example, a particular strain of Chlamydophila psittaci of birds may be associated with many deaths in a short period of time in an aviary of canaries and yet the same strain might be only occasionally associated with mild disease in a flock of parrots, or vice versa.

Many apparently healthy wild and captive birds are infected with this organism but do not show signs of disease due to this infection. They can remain carriers of the organisms without becoming ill for months, years and possibly, for life. Such birds can intermittently pass or release Chlamydophila organisms into their respiratory secretions and their faeces. It is usually via these that they can infect other birds and people.

The disease " chlamydophilosis " can develop suddenly or very slowly or anywhere in between, depending on the influence of a wide range of interacting factors such as nutrition, presence or absence of concurrent diseases, climate, stress, hygiene and sanitation, medications ... there are many more.

Increasingly chlamydophilosis is being seen as a disease affecting birds with a compromised immune system or concurrent diseases. Avian c chlamydophilosis can affect birds in many different ways ranging from apparently mild cases of conjunctivitis or "one eye cold", sinusitis and upper respiratory tract infections, infections of the lungs, air sacs, liver, spleen, gastrointestinal tract, other organs and sometimes of the nervous system. It can be a chronic debilitating disease in birds or it can be rapidly fatal.

There are many different ways of testing for and diagnosing avian chlamydophilosis, some of which are not always accurate or reliable. The "Clearview" chlamydia test is currently "popular" in Australia. This test is designed to detect the human venereal disease in samples taken from the penile urethra or human female genital region. The test is thought to be about about 85% reliable in helping diagnose infected birds if the samples to be tested are appropriate. Appropriate samples are conjunctival swabs from sore eyes, swabs of the nostrils and choana (the cleft in the palate area of birdÕs mouths) and from the cloaca provided faecal contamination is minimised.

Faecal samples are inappropriate samples to be used with this test as they often lead to many "false positive" results and a marked reduction in the reliability of the test. If the test is done on fresh faecal samples, certain bacteria which cross react with the "Clearview test" might be recognised in Gram stained smears. However, the use of this test to test samples sent by post is likely to often give misleading results and potentially result in the inappropriate sale and misuse of large amounts of tetracycline drugs, at considerable expense, for little gain, in my opinion.One therefore is prompted to ask if offering this test on stale faecal specimens sent by post or courier is ethical. It is hoped that this "dilemma" will be resolved by the development of an accurate, reliable, convenient and affordable in-house test in the forseeable future. It is rarely necessary or advisable to kill birds with chlamydophilosis. Perhaps an exception is where they have become moribund and another is when the bird is owned by someone with AIDS or cancer and no-one else can be found to take care of the bird.

Both apparently healthy carrier birds and birds affected with the disease can usually be treated such that they are no longer affected (sick) and no longer carry the organisms within their bodies. However a small percentage of birds remain infected despite all current treatments using the tetracycline group of drugs such treatment must be continued at effective daily dose rates for at least 45 days and often 60 days to eradicate the chlamydophila organisms from the body. Alternatively an injection of doxycycline can be given once a week for at least 7 consecutive weeks, although in some species shorter courses might be effective. Another drug that is sometimes used to treat chlamydophilosis is enrofloxacin. Be aware that these long course of antibiotics predispose yeast or "thrush" infections in some birds.

Pet birds and valuable aviary birds should be retested after treatment.

Birds can readily become re-infected from contaminated environments and other infected birds if their immune system is impaired through stress or other factors. It is essential that cages and aviaries of birds undergoing treatment be maintained "spotless" and be frequently cleaned and disinfected during the period of treatment of the birds. It is also important to prevent contact with wild birds and their droppings and to quarantine and treat any newly acquired birds before placing them in your aviary.

Prevention of chlamydophilosis includes good hygiene and sanitation, minimising dust and aerosols when cleaning, wearing a mask when cleaning and when performing necropsies on infected birds, and making sure all pet birds have been tested free from infection with Chlamydophila psittaci and also have been given a 45 to 60 day course of doxycycline as an added precaution.

At present there is no reliable effective vaccine against avian chlamydophilosis.

NEED TO KNOW! HUMAN DISEASE?

If you or a member of the family becomes sick and requires medical attention or is not responding to treatment, ask your Doctor "Could I have bird chlamydiosis?".

Stress the word BIRD!

Chlamydophilosis in people is usually associated with symptoms similar to those of mild to severe "flu" such as sore eyes, sore throat, intermittent fevers, severe headaches, cough, shortness of breath, various aches and pains but it can also be associated with liver and glandular disease, can mimic or be confused with some forms of cancer and can affect the brain.

Some people die from this disease each year, perhaps because in part, the disease was not promptly recognised for what it was. Many vets working with birds have become infected. Some have reported that at their lowest point in the disease their greatest fear was that they would NOT die! (They felt so sick and miserable.) However, once the appropriate treatment was started (usually 100- 200mg doxycycline hydrochloride once a day for 10 to 14 days) they felt much better within 1-2 days. Be sure to help your doctor by telling him or her that you associated with birds and by asking the above question if you are concerned. Your doctor might elect to start you on appropriate treatment as a precaution while awaiting the results of various blood such as a rising antibody titre and/or other tests.