Avian Chlamydiosis (Psittacosis) Pathology

The nature, cause, origin, and progress of Avian Chlamydiosis (Psittacosis).

Avian Chlamydiosis is a disease caused by the bacterium Chlamydophila psittaci, formerly known as Chlamydia psittaci. It is a member of the family Chlamydiaceae.

Birds - Avian Chlamydiosis
C. psittaci is the bacterial species generally associated with this disease in birds. The disease is usually transmitted from an infected pet bird of the parrot family. However, turkeys, chickens, pigeons, and almost any other bird can be infected.

The severity of the disease may range from no symptoms to high mortality and depends upon the strain of the C. psittaci and the susceptibility of the bird. Birds serve as the host organism and not all carriers display signs and symptoms. Birds may shed the bacteria intermittently or continuously for months; it is excreted in the feces and nasal discharges of infected birds. The bacteria is resistant to drying, and thus bird feces in cages and roosts are especially hazardous, as the bacterial can remain infective for several months.

Humans
Infection to humans commonly occurs from inhaling the bacteria in airborne particles from feces or respiratory exudates of infected birds. The disease most commonly affects pet-store workers, farmers, and slaughterhouse workers, or people who have recently purchased an infected bird. People with weakened immune systems such as the elderly, AIDS patients, and organ transplant recipients are more susceptible to the disease.