The Washington State Department of Health recently published a one-page educational document for health care providers to help determine possible sources of exposure to Legionella. This document offers an overview of proper diagnostic tests to order when Legionnaires’ disease is suspected.
In addition to a urine antigen test, DOH is encouraging health care providers to order a PCR (polymerase chain reaction) or culture test, which is run on a respiratory specimen (i.e. sputum, BAL (bronchoalveolar lavage). PCR and culture can identify all species and serogroups of Legionella bacteria that can cause disease, unlike the urine antigen test, which only detects Legionella pneumophila serogroup 1. Having clinical isolates of Legionella is essential to determine links among clinical cases and environmental sources. (Rosemary Mitchell Grant)
