parrot fever

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Related to parrot fever: ornithosis, parrot disease

Parrot Fever



Parrot fever is a rare infectious disease that causes pneumonia in humans. It is transmitted from pet birds or poultry. The illness is caused by a chlamydia, which is a type of intracellular parasite closely related to bacteria. Parrot fever is also called chlamydiosis, psittacosis, or ornithosis.


Parrot fever, which is referred to as avian psittacosis when it infects birds, is caused by Chlamydia psittaci. Pet birds in the parrot family, including parrots, parakeets, macaws, and cockatiels, are the most common carriers of the infection. Other birds that may also spread C. psittaci include pigeons, doves, mynah birds, and turkeys. Birds that are carrying the organism may appear healthy, but can shed it in their feces. The symptoms of avian psittacosis include inactivity, loss of appetite and ruffled feathers, diarrhea, runny eyes and nasal discharge, and green or yellow-green urine. Sick birds can be treated with antibiotics by a veterinarian.
C. psittaci is usually spread from birds to humans through exposure to infected bird feces during cage cleaning or by handling infected birds. In humans, parrot fever can range in severity from minor flu-like symptoms to severe and life-threatening pneumonia.

Causes and symptoms

Parrot fever is usually transmitted by inhaling dust from dried bird droppings or by handling infected birds. Humans can also spread the disease by person-to-person contact, but that is very rare. The symptoms usually develop within five to 14 days of exposure and include fever, headache, chills, loss of appetite, cough, and tiredness. In the most severe cases of parrot fever, the patient develops pneumonia. People who work in pet shops or who keep pet birds are the most likely to become infected.


Only 100-200 cases of parrot fever are reported each year in the United States. It is possible, however, that the illness is more common since it is easily confused with other types of influenza or pneumonia. Doctors are most likely to consider a diagnosis of parrot fever if the patient has a recent history of exposure to birds. The diagnosis can be confirmed by blood tests for antibodies, usually complement fixation or immunofluorescence tests. The organism is difficult to culture. A chest x ray may also be used to diagnose the pneumonia caused by C. psittaci.


Psittacosis is treated with an antibiotic, usually tetracycline (Achromycin, Sumycin); doxycycline (Doxy, Vibramycin); or erythromycin (Eryc, Ilotycin). Oral medication is typically prescribed for at least 10-14 days. Severely ill patients may be given intravenous antibiotics for the first few days of therapy.


The prognosis for recovery is excellent; with antibiotic treatment, more than 99% of patients with parrot fever will recover. Severe infections, however, may be fatal to the elderly, untreated persons, and persons with weak immune systems.


As of 1998, there is no vaccine that is effective against parrot fever. Birds that are imported into the country as pets should be quarantined to ensure that they are not infected before they can be sold. Health authorities recommend that breeders and importers feed imported birds a special blend of feed mixed with antibiotics for 45 days to ensure that any C. psittaci organisms are destroyed. In addition, bird cages and food and water bowls should be cleaned daily.

Key terms

Avian chlamydiosis — An illness in pet birds and poultry caused by Chlamydia psittaci. It is also known as parrot fever in birds.
Chlamydia psittaci — An organism related to bacteria that infects some types of birds and can be transmitted to humans to cause parrot fever.
Chlamydiosis, psittacosis, or ornithosis — Other names for parrot fever in humans.



Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311.


"Psittacosis (Parrot Fever; Ornithosis)." ThriveOnline.


a disease due to a strain of Chlamydia psittaci; it was first seen in parrots and later was found in other birds and domestic fowl (in which it is called ornithosis). It is transmissible to humans. The etiologic organism is inhaled into the body and attacks the respiratory tract. The first symptoms appear after an incubation period of 6 to 15 days and include fever, sore throat, headache, loss of appetite, chills, and profuse sweating. Later there may be coughing, difficulty in breathing, abdominal distress, and often splenomegaly. Prostration may occur. Infiltrates may appear in the chest x-ray. Special laboratory tests are necessary for accurate diagnosis. Psittacosis usually runs its course in 2 or 3 weeks. Complications may be avoided by the administration of such antibiotics as tetracycline and penicillin. Fatalities are uncommon.


An infectious disease in psittacine birds and humans caused by the bacterium Chlamydophila psittaci (formerly Chlamydia psittaci). Avian infections are mainly inapparent or latent, although acute disease does occur; human infections may result in mild disease with a flulike syndrome or in severe disease, especially in older people, with symptoms of bronchopneumonia.
Synonym(s): Parrot disease (3) , parrot fever
[G. psittakos, a parrot, + -osis, condition]

parrot fever

A type of hypersensitivity pneumonitis—extrinsic allergic alveolitis—caused by allergy to bird components or bird droppings, avian serum or gut proteins
At risk birds Budgerigars, chickens, ducks, parakeets, pigeons, turkeys


An infectious disease in psittacine birds and humans caused by the bacterium Chlamydia psittaci. Avian infections are mainly inapparent or latent, although acute disease does occur; human infections may result in mild disease with a flulike syndrome or in severe disease, with symptoms of bronchopneumonia.
Synonym(s): ornithosis, Parrot disease (3) , parrot fever.
[G. psittakos, a parrot, + -osis, condition]

parrot fever