Psittacosis is a notifiable condition. Patient isolation is usually not required as human-to-human transmission is rare.
Pneumonia due to Chlamydia psittaci cannot be clinically differentiated from other community-acquired, atypical pneumonias. Molecular testing and/or serology is required to confirm the diagnosis.
Tetracycline antibiotics are the preferred treatment; however, other antibiotics may be used as an alternative in select patients.
Patients generally respond well to antibiotics, with resolution of symptoms within 24 to 48 hours, although there is the potential for relapse from persistent infection.
Infection caused by the obligate, intracellular, gram-negative bacterium Chlamydia psittaci (formerly known as Chlamydophila psittaci), which causes community-acquired, atypical pneumonia or conjunctivitis. It is predominantly a pathogen of birds and mammals; humans are an accidental host. Exposure to infected birds is a common cause. Also known as parrot fever or ornithosis.
History and exam
Key diagnostic factors
- presence of risk factors
- illness in other family members
Other diagnostic factors
- sore throat
- exposure to infected birds and mammals
- young children
- older adults
1st investigations to order
- white blood cell count with differential
- liver function tests
- polymerase chain reaction (PCR)
- chest x-ray
Investigations to consider
children ≥8 years of age and non-pregnant adults
children <8 years and pregnant women
Deborah Dean, MD, MPH
Children’s Global Health Initiative
Center for Immunobiology and Vaccine Development
Professor of Medicine
University of California at San Francisco and Berkeley
Faculty, the UC Berkeley - UCSF Graduate Program in Bioengineering
Children's Hospital Oakland Research Institute
DD is an author of some references cited in this topic.
Servaas Morre, PhD
Head of Laboratory of Immunogenetics
VU University Medical Center
Department of Pathology
Laboratory of Immunogenetics
SM declares that he has no competing interests.
William A. Petri, Jr., MD, PhD, FACP
Chief and Professor of Medicine
Division of Infectious Diseases and International Health
University of Virginia Health System
WAP declares that he has no competing interests.
- Atypical pneumonia caused by other pathogens
- Infective endocarditis
- Compendium of measures to control Chlamydia psittaci infection among humans (psittacosis) and pet birds (avian chlamydiosis)
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