Psittacosis in the Native Australian Budgerigars

Abstract

Soon after the discovery of latent psittacosis in the breeding establishments of California the sanitation of the aviaries became a paramount problem. A proposal was made to destroy the flocks which were proven to be infected and to resume breeding in the disinfected pens with a native stock imported from Australia. Such a plan might be feasible only provided the native birds should be free from disease. According to reliable reports no psittacosis has been observed or reported from the Australian continent. It was thus anticipated that the budgerigars would possess a high susceptibility to the virus and would therefore lend themselves for exposure and immunity tests.

Permission was obtained to export 200 shell parrakeets through the port of Sydney. The birds had been trapped during the month of June in the vicinity of Adelaide a few days before they left the country. They had no contact with other birds either on land or at sea. On their arrival in 8 large cages, in July, 1933, the green, partly mature and partly immature budgerigars appeared perfectly healthy and remained so under strict isolation in a special room in a separate building removed from any psittacosis work which was in progress.

One month after arrival one bird died in Cage 4. The autopsy was inconclusive but mice inoculated with the spleen and liver suspensions sickened on the 5th to the 7th day and when sacrificed presented enlarged spleens. Aerobic and anaerobic cultures remained sterile. By passage experiments and filtration tests a virus was obtained which produced the typical lesions in mice and infected rice birds by inoculation and per os. The inclusion bodies (L. C. L. bodies) were readily demonstrated. Following this unexpected discovery of the psittacosis virus 10 birds each from Cages 3, 4, 5, 6, 7, and 8 were sacrificed and examined by mouse inoculation tests. In 8 shell parrakeets the virus was present in the spleens and livers and in the nasal mucosa also of one other bird.