• An acute febrile disease characterized by pneumonitis and other systemic symptoms
  • The name is derived from the Greek for parrot, psittakos; thus, psittacosis is often referred to as “parrot disease.”
  • Also known as ornithosis


  • Birds are the major reservoir of the psittacosis pathogen.
  • Nearly all domestic and wild birds may spread this infection.
  • Psittacine birds (parakeets, parrots, and macaws) are a major source of disease in the United States, but pigeons and turkeys are also common culprits.
    • Infecting agent is present in bird nasal secretions, urine, feces, feathers, viscera, and carcasses.
    • Inhalation of aerosols of feces, urine, and secretions of infected birds is the most common route of infection.
    • Handling of plumage, bird bites, and mouth-to-beak contact are known to spread infection.
    • Birds may be healthy or sick.
  • Most reported cases (70%) are the result of exposure to pet caged birds (especially parrots, parakeets).
  • Most common mammalian source of infection is sheep.
  • Occupational hazard of workers in poultry plants, pet shops, zoos, farms
  • Rarely transmitted person to person


  • Only 100–200 total cases reported in United States each year
  • Very rare disease in young children

Risk Factors

Close human contact with birds and, in some cases, sheep

General Prevention

  • Epidemiologic investigation is indicated in all suspected cases.
  • Birds suspected to be infected should be killed, transported, and analyzed by qualified experts.
  • Potentially contaminated living areas where bird was kept should be disinfected and aired.
  • Pathogen is susceptible to most household disinfectants (rubbing alcohol, Lysol, bleach).


  • Inhalation of aerosolized organisms into the respiratory tract
  • Incubation period 5–14 days; may be longer
  • Spreads via bloodstream to lungs, liver, and spleen
  • Lymphocytic inflammatory alveolar response


  • Infection produced by Chlamydophila psittaci, an obligate intracellular parasitic bacterium
  • Morphologically, antigenically, and genetically different from Chlamydia species

Commonly Associated Conditions

Pneumonitis (with a severe headache) is a common presentation.

There's more to see -- the rest of this topic is available only to subscribers.