Serological testing for CAP in adults

Serological testing is rarely useful in the acute management of CAP in adults.

Serological testing detects a rise in serum antibodies in response to infection; however, this rise can be delayed so the absence of antibodies does not exclude infection. Antibodies can be detected for prolonged periods of time, so a positive result can reflect past infection rather than current infection.

Available serological tests for CAP include serology for Burkholderia pseudomallei, Chlamydophila (Chlamydia) pneumoniae, Chlamydophila (Chlamydia) psittaci, Coxiella burnetii, Legionella species and M. pneumoniae. Consider storing serum for serological testing if one of these pathogens is suspected based on epidemiology, or for patients with high-severity CAP. Serological tests are likely to be replaced by NAAT (eg PCR) as tests for these pathogens become more available.

For a list of other clinical and microbiological investigations for CAP in adults, see Clinical and microbiological investigations for community-acquired pneumonia (CAP) in adults.