Chlamydophila psittaci (formerly Chlamydia psittaci) is an immobile gram-negative bacterium from the Chlamydia family. This energy parasite is an animal- and human-pathogenic organism that draws its energy from a host cell. Only through this process can the bacterium multiply intracellularly as a vacuole (cell organelle) and escape the host’s own antibodies. Cp. psittaci can primarily cause infections in birds, but also in mammals. In humans, the disease manifests itself in the form of ornithosis, also known as parrot disease, and it can occur worldwide.
The bacterium Cp. psittaci is present in secretions from the birds’ respiratory tracts, in their excrements and in feathers. In the bodies of songbirds, it may occur in the form of asymptomatic persistence (occurrence without symptoms). If left untreated, a bird may become a permanent germ carrier and a continual danger for the keeper, since the bacterium is transmitted to humans by droplet infection, as well as through direct contact with the bird. However, the bacteria cannot be transmitted between humans.
An infection with Cp. psittaci generally leads to ornithosis accompanied by atypical and interstitial pneumonia (a type of lung disease that also affects the thin network of tissues between the organs). After an incubation period of about one to four weeks, flu-like symptoms such as chills, fever, headache, muscle pain and inflammatory skin rash set in. As a result of the interstitial lung disease, an irritable cough may develop. The patient affected by Cp. psittaci may develop MALT lymphoma, a rare form of non-Hodgkin’s lymphoma, as well as pathological spleen enlargement in 70 per cent of cases. The symptoms decrease after several weeks and the patient builds up a lifelong immunity.
As there is no evidence of direct human-to-human transmission, implementing basic hygiene measures are sufficient. According to the German Infection Protection Act (§ 7), Cp. psittaci must be reported if there is evidence of an acute infection.
The required spectrum of activity against Cp. psittaci is: bactericidal.