Clinical Features and Complications
Clinical presentations of psittacosis can vary widely from no evidence of infection to severe systemic disease accompanied by pneumonia. The predominant presentation is upper respiratory tract infection with constitutional symptoms. In humans, symptomatic infections typically present as:
- Abrupt onset of fever and chills
- Muscle aches
- Nonproductive cough
Pneumonia is evident often on chest x-ray. Radiographic findings may include lobar or interstitial infiltrates.
Patients may present with pulse-temperature dissociation (fever without increased pulse rate), splenomegaly, and rash, though less frequently.
The incubation period is typically 5 to 14 days. Less commonly, symptoms may begin more than 14 days after exposure.
Severe complications can result in hospitalization. Reported complications include:
- Severe pneumonia requiring intensive-care support
- Respiratory failure
Death occurs in less than 1% of properly treated patients.
- Balsamo G, Maxted AM, Midla JW, et al. Compendium of measures to control Chlamydia psittaci infection among humans (psittacosis) and pet birds (avian chlamydosis), 2017Cdc-pdfExternal. J Avian Med Surg. 2017;31(3):262–82.
- Chlamydophila psittaci: Pathogen safety data sheet — infectious substancesExternal, Public Health Agency of Canada, April 2013.
- Schlossberg D. Psittacosis (due to Chlamydia psittaci). In JE Bennet, R Dolin, MJ Blaser, editors. 8th ed. Mandell, Douglas, and Bennett’s Principles and practice of infectious diseases. Philadelphia. Elsevier Saunders. 2015: 2171–3.