THE INCREASING popularity of parakeets as domestic pets, the lack of uniform laws regarding the importation and sale of psittacine birds, and the presence of a large reservoir of the disease among domestic fowl have increased the incidence of psittacosis tremendously. Since Ritter first described the disease under the name of pneumotyphus, psittacosis has been reported as endemic or epidemic in many parts of the world. Any attempt to determine the true incidence of the disease is futile. It is certain that psittacosis occurs much more frequently than is generally realized. That it is overlooked because of the unawareness of the medical profession of its existence is most likely.
Psittacosis is an acute infectious disease caused by a number of closely related viruses. In addition to the strains of psittacine origin, there are various other strains which naturally infect other species of birds. These latter infections are referred to as