Chlamydia psittaci is both a respiratory and an ocular pathogen acquired from domesticated or commercially raised birds, mammals, exotic imported birds, and feral animals.
Pneumonia due to C psittaci can present similarly to atypical pneumonia due to Chlamydia pneumoniae and Mycoplasma pneumoniae .
Diagnosis is based on molecular testing and serology.
Tetracyclines are the preferred treatment. Macrolides, fluoroquinolones, and other agents such as chloramphenicol may be used as alternatives.
Patients respond well to antibiotic treatment, with resolution of symptoms within 24 hours, although there is the potential for relapse from persistent infection.
Psittacosis is an infection caused by the obligate, intracellular, gram-negative bacterium Chlamydia psittaci (formerly known as Chlamyodophila psittaci ).  It is a pathogen of birds and mammals; humans are an accidental host.  Infection in humans occurs in all age groups worldwide. It causes community-acquired, atypical pneumonia and conjunctivitis.   Also known as parrot fever or ornithosis.
Children’s Global Health Initiative
Center for Immunobiology and Vaccine Development
Professor of Medicine
University of Calif. at San Francisco and Berkeley
Faculty, the UC Berkeley - UCSF Graduate Program in Bioengineering
Children's Hospital Oakland Research Institute
DD declares that she has no competing interests.
Head of Laboratory of Immunogenetics
VU University Medical Center
Department of Pathology
Laboratory of Immunogenetics
SM declares that he has no competing interests.
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.
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