We received an update from healthcare epidemiologists on a rise in Legionella detected in the community in Chicago. 16 cases have been reported to the Chicago Department of Public Health since July 1st 2021 and are currently under investigation. Here are a few clinical pearls:
-Consider Legionella in anybody presenting with a pneumonia. Risk factors include age > 50yo, a smoking history, chronic lung or immunocompromising conditions
-Diagnostic testing: The preferred diagnostic test is isolation on a sputum or BAL culture (this is a separate order in Epic specifically for Legionella). Urinary antigens can also be sent but will only detect serogroup 1 (which is most prevalent but there are 15 groups!) – testing for this serogroup may have a sensitivity 70-100% and specificity 95-100%.
-Reporting: REPORTING/CONTACT INFORMATION: Legionella cases should be reported to Chicago Department of Public Health by calling 312-743-9000 or via the Illinois National Electronic Disease Surveillance System (INEDSS).
Sources:
https://www.cdc.gov/legionella/clinicians/diagnostic-testing.html