Ornithosis
Ornithosis, also known as psittacosis, is an infectious disease caused by the bacterium Chlamydophila psittaci, primarily transmitted from birds to humans. The disease manifests with flulike symptoms, including cough, fever, chills, and can lead to pneumonia or, in rare cases, death. Transmission occurs mainly through inhaling airborne particles from dried bird droppings, secretions, feathers, and eggs, making individuals who work with birds—such as breeders, veterinarians, and poultry workers—particularly vulnerable. The incubation period for ornithosis ranges from one to four weeks, with symptoms typically appearing within ten days of infection.
Diagnosis involves physical examinations, blood tests, and imaging techniques, while treatment generally includes antibiotics such as doxycycline and tetracycline, with careful monitoring needed for severe cases. Preventive measures for pet owners include maintaining clean birdcages and administering antibiotics to imported birds to reduce infection risk. Awareness of the disease and its transmission can help mitigate the risks, especially for those with weakened immune systems.
Ornithosis
- ANATOMY OR SYSTEM AFFECTED: Lungs, respiratory system
- ALSO KNOWN AS: Parrot disease, parrot fever, psittacosis
Definition
Ornithosis is an infectious disease spread by birds to humans through the bacterium Chlamydophila psittaci, resulting in flulike symptoms, pneumonia, and, rarely, death.
Causes
Ornithosis is primarily spread through bird droppings, although a bird’s secretions, feathers, and eggs also carry the disease. Bird droppings remain infectious for weeks and, especially after desiccation, become airborne and are easily inhaled by humans. Handling diseased birds, ingesting their eggs, or breathing the dust particles of bird feces all cause the spread of ornithosis.
Risk Factors
Persons such as breeders or pet store workers who raise parrots, cockatiels, and parakeets as pets are most at risk of contracting ornithosis. Veterinarians and veterinarian staff are also highly vulnerable. Because chickens, turkeys, gulls, pigeons, and a wide variety of other birds may be carriers of ornithosis, poultry workers, farmers, and bird slaughterhouse workers are also at risk for exposure to the disease. Persons who have a weakened immune system also are at greater risk of contracting ornithosis.
Symptoms
The symptoms of ornithosis include a cough, rash, fever, chills, headache, fatigue, muscle aches, weight loss, congestion, breathlessness, and pneumonia. (In birds, the symptoms are discharge from eyes and nose, loss of appetite, wasting, diarrhea, and ruffled and unkempt coats and feathers.)
Screening and Diagnosis
A physical examination, blood test, sputum culture, chest X-ray, and computed tomography scan of the chest are all used to correctly diagnose ornithosis. Further screening may be carried out by isolating specific contact with birds in the weeks before the onset of illness because the incubation period of ornithosis is one to four weeks. Most often, symptoms manifest within ten days of infection.
Treatment and Therapy
The antibiotics doxycycline and tetracycline are primarily prescribed for ornithosis, although rifampin, azithromicin, and erythromycin may also be prescribed, especially for pregnant women and for children under the age of nine years. Most cases of ornithosis are treated successfully with oral antibiotics, but severe cases require antibiotics administered intravenously. It is essential that elderly persons in particular begin treatment as soon as possible. Rare cases of ornithosis, less than 1 percent, result in death.
Prevention and Outcomes
For pet-bird owners, the best prevention is to keep birdcages clean so that no bird droppings can accumulate, dry, and become inhaled. Additionally, tetracycline should be administered to imported birds as pets for a minimum of forty-five consecutive days to reduce the likelihood of infection. Veterinarians, laboratory technicians, and anyone exposed to infected birds should always wear gloves and a mask to avoid secretions and airborne bacteria.
Bibliography
Fryden, Aril, et al. “A Clinical and Epidemiological Study of Ornithosis’ Caused by Chlamydia psittacia and Chlamydia pneumoniae (Strain TWAR).” Scandinavian Journal of Infectious Diseases 21 (1989): 681-691.
Hall, C., et al. “An Epidemic of Ornithosis in Texas Turkeys in 1974.” Southwestern Veterinarian 28 (1975): 19-21.
Irons, J., Thelma Sullivan, and Joyce Rowen. “Outbreak of Psittacosis (Ornithosis) from Working with Turkeys or Chickens.” American Journal of Public Health 41 (1951): 931-937.
National Association of State Public Health Veterinarians. “Compendium of Measures to Control Chlamydophila psittaci Infection Among Humans (Psittacosis) and Pet Birds (Avian Chlamydiosis).” 2010. Available at http://www.nasphv.org/documents/psittacosis.pdf. Accessed 4 Feb. 2025.
"Psittacosis (Ornithosis) Fact Sheet." NSW Health, 31 Jan. 2024, www.nasphv.org/documents/psittacosis.pdf. Accessed 4 Feb. 2025.
Schlossberg, D. "Chlamydia psittaci (Psittacosis).” In Mandell, Douglas, and Bennett’s Principles and Practice of Infectious Diseases, edited by Gerald L. Mandell, John F. Bennett, and Raphael Dolin. 7th ed. New York: Churchill Livingstone/Elsevier, 2010.