Chlamydia psittaci infection can be the cause of fever, anorexia, lethargy, diarrhoea, excretion of green to yellow urates and occasionally shock and death in birds. Infection can be associated with conjunctivitis, enteritis, pericarditis, air sacculitis, sinusitis, coelomitis, hepatitis and splenitis. The importance of this infection in birds is enhanced by its zoonotic potential. C. psittaci infection has been demonstrated in over 460 bird species with the highest infections rates reported in psittacine birds and pigeons. Survivors of infection can become asymptomatic carriers. Transmission is from close proximity to another infected bird. The bacteria are shed in nasal secretions and faeces – faecal shedding is intermittent and can be activated by any cause of stress. The organism can survive in the environment for several months if protected by organic debris. Predator or scavenger species can become infected through consumption of the carcass of an infected bird. Nest transmission is possible through regurgitation feeding and via biting/blood-sucking arthropods.
Human infections (psittacosis) occur most commonly from inhaling aerosolized organisms from urine, respiratory secretions or dried faeces. Beaks to mouth contact, a bite from an infected bird or handling the plumage of an infected bird are other possible sources of infection. Appropriate protective equipment should be used if performing a post-mortem on an infected bird.
PCR is the preferred test to confirm infection. Culture, antigen detection (Clearview test) and serum antibody detection by IFAT are also available. Histopathology may reveal lesions suggestive of chlamydia infection, which can then be confirmed by PCR.
- Fresh spleen or liver, dry swabs (cloacal, upper respiratory, conjunctiva)
Antigen detection (Clearview test)
- Dry swab (cloacal, organ), faeces
- Fresh spleen or liver, cloacal swab, conjunctival swab (only if showing conjunctivitis) in chlamydia culture media. This is a referral test so turnaround time can be prolonged.
- IFAT (all species): serum or swab
- Fixed liver and spleen (consider submitting a full range of post-mortem tissue samples to allow detection of other diseases)
Plain yellow-top pot (dry swabs, fresh tissue, faeces)
Chlamydia culture media (culture only)
Formalin pots (histopathology)
Special handling/shipping requirements:
Specimens should be shipped chilled, double-bagged and in a leak-proof container, as this is a zoonotic organism.