AN OUTBREAK OF PSITTACOSIS I N PIGEONS, INVOLVING T H E PRODUCTION OF INCLUSION BODIES, AND TRANSFER OF T H E DISEASE TO MAN Bx

Spontaneous infection with the virus of psittacosis is known to be widespread among birds of the psittacine family and also to occur in members of other orders of the class, Ayes (1). Coles (2) in 1940 described an epizootic of psittacosis among domestic pigeons (Columba livia vat. domestica) in South Africa and this disease was later encountered among pigeons in many parts of the United States (3-5). Although no human infections were associated with the first epizootic, Meyer and his coworkers (3, 6) subsequently reported the transmission of psittacosis from pigeons to man. A recent article by Smadel (5) indicates that at least one-fourth of the individuals in a'group of 45 persons with sporadic atypical pneumonia were infected with strains of the virus of psittacosis, and that the majority of the patients with psittacosis had direct or indirect contact with diseased pigeons. Such observations as these, as well as those of Eaton and Corey (7), demonstrate that psittacosis is a more common human disease than was previously recognized. In order to understand fully the epidemiology of this newly recognized form of psittacosis in man further information concerning the spontaneous disease in pigeons and other birds is needed. Observations made on an outbreak of psittacosis in a flock of pigeons and on the disease encountered in two persons who handled the sick birds are the subject of this report. We shall speak of the psittacosis-lymphogranuloma venereum group of viruses when discussing this family of agents; furthermore, we shall consider the psittacosis virus encountered in pigeons and parrots as strains of the same agent. A number of articles can be consulted for a discussion of the relationship of the viruses of psittacosis, lymphogranuloma venereum, and other allied agents (5-9).