Psittacosis (or ornithosis or parrot fever) is a disease caused by a bacterial infection that is relatively common in pet birds in Hong Kong. The bacteria that causes this disease is called Chlamydophila psittaci. This disease is extremely contagious between birds, and humans can catch the virus too.
Transmission
This bacteria is shed in the faeces, and in discharge from the eyes or nose of infected birds. Some infected birds can appear healthy but can still shed the organism from time to time. When a bird is under stress shedding can worsen; stressful events include egg laying, rearing of young, moving cage, moving house, crowding, and a drop in temperature. The faeces containing the bacteria can then dry out, turn into dust and spread the disease further. Pet shops and bird markets such as ‘Bird Street’ are prime locations for birds to catch the disease. Birds that have been illegally imported are also likely to be infected.
You need to remember that a bird can have the bacteria and can still spread the disease, even if it isn’t showing any symptoms.
Clinical signs
There are no specific signs that indicate that a bird has Psittacosis. However, the following signs may be suggestive:
- Discharge from the eyes and nostrils
- They are excessively sneezing
- Loss of apetite
- They have lost weight
- Suffering from depress, sitting fluffed up at the bottom of their cage
- Green/yellow droppings with a watery consistency
Diagnosis
An exact diagnosis of Psittacosis is difficult because there no test is 100% reliable on a living bird. Veterinarians will often have a working diagnosis based on the bird’s symptoms, history, blood tests and radiographs.
Testing
There are several testing options to help diagnose this disease:
- DNA testing (PCR): A PCR test is performed in a special laboratory after taking swabs of the bird’s conjunctiva (eye), choana (roof of mouth) and cloaca (anus) by our veterinarian. Unfortunately, test results can often come back negative if the infected bird isn’t shedding the virus.
- Blood test (serology): This test is performed using a blood sample taken from the bird. The blood test looks for antibodies in the blood of the bird to check if the animal has been exposed to the bacteria or not.
Unfortunately this test can only detect exposure in the past, it can’t tell the difference between an old (and already cured) infection and an on-going infection.
Treatment
The recommended treatment is a particular antibiotic for a long term (45 days). Successful treatment of the disease is based on how long the bird has been ill, the age of the bird, its species and other concurrent infection. For parrots, we recommend weekly antibiotic injections once a week for a period of 6-7 weeks. At the same time as this, the medicine can be given by mouth as well.
As soon as a bird is diagnosed with Psittacosis, it must be isolated from other birds. If the infected bird has been in recent contact, then other birds in the house may need to be tested or treated as well. There is no immunity to the disease – birds are susceptible to re-infection even after full recovery from the infection.
Psittacosis in humans
It is relatively rare that the disease is passed on to humans and cannot be passed from human to human. Infection with psittacosis usually occurs when a person breathes in organisms in the air from dried faeces or respiratory tract secretions, from sneezing of infected birds. You can also contract the disease from kissing birds, or handle feathers plucked from the infected animal. Humans that are potentially at a higher risk of infection include those whose immune systems are not working well, the very young and the elderly. This disease has an incubation period of anywhere between 5 – 14 days.
The seriousness of the disease ranges from a mild, non-specific illness to a severe illness with severe pneumonia. Human symptoms are similar to those of hypothermia: fever, chills, headache, muscle aches or respiratory signs (cough, difficulty breathing). If you do visit the doctor having experienced these symptoms for an abnormal amount of time, it would be worth mentioning you have come into contact with birds.
Preventing psittacosis in humans
- Whilst treating your pet bird, try to keep contact with them to a minimum. However tempting it might be, do not kiss your bird or put them near your face/mouth as the bacteria can be shed from their eyes and respiratory tract. Keep them in a well lit, well ventilated room that no-one uses very often, and make sure it stays clean.
- When cleaning the cage, make sure you wear glove and masks. This helps reduce the risk of you breathing in faecal dust.
- Make sure the bird cage is kept clean to decrease the build-up of infected faeces. The cage can be disinfected with diluted bleach (mix 120 ml bleach in 2 L of water). Make sure the bleach in in contact with the cage for 10-15 minutes at a minimum. The cage should then be rinsed with warm water. Move the bird to another room when bleaching the cage, bleach can be very irritating to their respiratory tract.
Preventing psittacosis in your bird
An infected bird must be kept quarantined for 6 weeks. Unfortunately this means do not let your new bird or anything it uses (e.g. food bowls) have any contact with your previous birds for at least 6 weeks. To be safe, keep it in a different room!
If you do buy a new bird during the quarantine process, you must bring it to our veterinarian for examination and testing.
If a bird looks ill, do not buy it. Try to buy new animals directly from a reliable breeder and not from a pet shop or market. The stress caused by transportation to a pet shop combined with a variety of birds from different sources are very common causes of illnesses.
Do not buy anything (live animal, toys, cages, or food) from pet shops with sick birds or dirty cages.
Do not allow your new bird to come into contact with other birds. This includes other pet birds when boarding, when visiting a pet store for tail trims/wing trims and wild birds.