Diagnosis, Treatment, and Prevention
Diagnosis of psittacosis can be difficult. Laboratories use several methods to detect Chlamydia psittaci infection. See the table below for advantages and disadvantages of different methods for diagnosing psittacosis.
Some tests are only available in specialized laboratories, and many laboratories may not offer any test for C. psittaci. When additional or specialized testing is necessary, local or state public health laboratories may be able to provide diagnostic support or forward specimens to CDC.
Laboratories typically perform tests on sputum specimens or swabs of the nasopharynx and oropharynx or serum, depending on the method used. In severe cases, other specimen types may be used. Clinicians should confirm the recommended specimen types with the laboratory receiving the specimen.
Advantages and disadvantages of select C. psittaci diagnostic methods
|Serology (e.g.; complement fixation, microimmunofluorescent antibody test)||
|Molecular (e.g. real-time PCR)1||
Chlamydia psittaci are sensitive to both macrolides and tetracyclines. However, tetracyclines are the drugs of choice, unless contraindicated due to reported macrolide failures. Tetracyclines are generally avoided in children aged <8 years, and macrolides are the drug of choice for children; however, tetracyclines could be considered when the benefits outweighs the risks, such as in life-threatening conditions or when macrolide failure is suspected.
As psittacosis can be difficult to diagnose, clinicians should be aware that proper antibiotic treatment ensures quick recovery time. People with more severe presentation should be treated with doxycycline right away if psittacosis is suspected.
Patient isolation and prophylaxis of contacts are usually not indicated, as person-to-person transmission of C. psittaci is rare.
Most states require clinicians to report cases of psittacosis to the appropriate health authorities. Timely diagnosis and reporting may aid in identifying the source of the infection and controlling the spread of disease.
Educate patients about the importance of handling birds and cleaning bird cages safely. Refer birds suspected as the source of human infection to veterinarians for evaluation and treatment.
- Balsamo G, Maxted AM, Midla JW, et al. Compendium of measures to control Chlamydia psittaci infection among humans (psittacosis) and pet birds (avian chlamydosis), 2017pdf iconexternal icon. J Avian Med Surg. 2017;31(3):262–82.
- Chlamydophila psittaci: Pathogen safety data sheet — infectious substancesexternal icon, Public Health Agency of Canada, April 2013.
- Mitchell SL, Wolff BJ, Thacker WL, et al. Genotyping of Chlamydophila psittaci by real-time PCR and high-resolution melt analysisexternal icon. J Clin Microbiol. 2009;47(1):175–81.
- Wolff BJ, Morrison SS, Pesti D, et al. Chlamydia psittaci comparative genomics reveals intraspecies variations in the putative outer membrane and type III secretion system genesexternal icon. Microbiology. 2015;161(7):1378–91.
- Case report forms and other resourcesexternal icon are available from the National Association of State Public Health Veterinarians.
1 The National Notifiable Diseases Surveillance System case definition currently considers an illness with characteristic symptoms and detection of C. psittaci nucleic acid in patient specimen via real-time polymerase chain reaction (PCR) to be a probable, but not confirmed, case.