An epidemic of avian and human psittacosis.

Psittacosis may occur in epidemic or sporadic form. We report an outbreak of avian and human psittacosis associated with an aviary in Philadelphia, Pa. The epidemic spread among birds in the aviary and then to men and women who were in contact with the birds. Chlamydia psittaci was cultured from infected birds, and the human patients were evaluated clinically and serologically. After proper treatment of the birds, cleaning of their cages, and institution of appropriate bird-handling techniques, the outbreak among the birds resolved. The human patients were treated, and no subsequent cases have been seen.