Psittacosis

PSITTACOSIS

Psittacosis is a zoonosis, caused by bacteria of the Chlamydia family. It occurs naturally in many species of birds, such as domesticated parrots, and these occasionally infect humans, typically when parrots are kept in inadequately cleaned cages in a confined space frequented by their human owner. Psittacosis is also an occupational hazard of workers in aviaries, and outbreaks have been reported among workers in poultry farms and processing plants. However, in the twenty-first century even isolated cases are uncommon, either because of improved standards of cleanliness in places where birds are kept and poultry is processed, or owing to other ecological factors. It is more likely to occur after exposure to birds imported from Latin America or Asia than those reared in the United States.

The usual mode of infection is via infected droppings or detritus on the infected bird's feathers. Psittacosis causes a feverish illness resembling pneumonia, occasionally with other manifestations, including skin rashes and inflammation of the membranes around the brain and spinal cord. It is an indolent infection that responds sluggishly to antibiotics of the tetracycline family, and can be fatal, although this is rare. Prevention depends on education of persons who are in close and continuing contact with birds, maintaining scrupulous cleanliness of bird cages, and surveillance of known or potential foci of infection such as poultry farms and shops that sell pet birds. Quarantine is applied to poultry farms and premises where infected birds have been found, and can be enforced when suspected infected birds are imported from other parts of the world.

JOHN M. LAST

(SEE ALSO: Zoonoses)