• 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).
  • Psittacosis is mainly an occupational disease among workers in poultry plants, duck or goose pluckers, pigeon breeders, pet store employees, and workers on farms and in zoos.
  • Most common mammalian source of infection is sheep.
  • Person-to-person transmission is so unusual that isolation of the infected patient is likely unnecessary.


  • Psittacosis is rare in humans.
  • Only 100 to 200 total cases reported in United States each year. The Centers for Disease Control and Prevention (CDC) noted 813 cases of psittacosis from 1988 to 1998.
  • Very rare disease in young children


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


  • 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, bleach).
  • The U.S. Department of Agriculture (USDA) requires veterinary inspection of birds at the first port of entry into the United States and quarantine for a minimum of 30 days at USDA-approved facilities to ensure the birds are free of evidence of communicable diseases.
  • In addition, during U.S. quarantine, psittacine birds receive medicated feed containing chlortetracycline for the entire quarantine period as a precautionary measure against avian chlamydiosis.
  • Human psittacosis is a nationally notifiable disease and should be reported to public health authorities.


  • Inhalation of aerosolized organisms into the respiratory tract
  • Incubation period 5 to 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


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

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