Date Sent: 08/04/2017 10:33 AM EDT
Sender: Michigan Health Alert Network
Subject: Increase in Legionnaires' Disease Cases in Southeast Michigan
The Michigan Department of Health and Human Services (MDHHS) is coordinating with the Macomb County Health Department, Oakland County Health Division, City of Detroit Health Department, and Wayne County Department of Health, Veterans, and Community Wellness following the identification of an increase in the number of cases of Legionnaires’ disease in southeast Michigan this summer. In June and July of 2017, 73 cases were identified in this region—a 143% increase from average total cases in June and July from 2014-2016 (30 cases). While legionellosis cases are most common in the summer and early fall, this increase is higher than expected for southeast Michigan for this time of year. The MDHHS is requesting that providers place Legionnaires’ disease higher on their differential diagnosis, when patients with pneumonia and existing risk factors for this infection present for care. To date, no common source of infection has been identified.
Legionella bacteria causes two forms of legionellosis respiratory infections. Legionnaires’ disease is the more severe infection that includes symptoms of fever, cough, and radiologic findings consistent with pneumonia. A milder form of legionellosis, Pontiac fever, is an influenza-like illness without pneumonia that resolves on its own. Individuals at higher risk for Legionnaires’ disease include those who are older than 50 years of age; have a current or past smoking history; or have an underlying illness or condition such as chronic lung disease, kidney or liver failure, diabetes, systemic malignancies, or immune system disorders due to medications or disease. Recent travel and overnight stays in hospitals or other healthcare facilities can increase an individual’s risk for Legionnaires’ disease.
Patients with pneumonia should be tested for Legionnaires’ disease if they have any of the following histories:
Legionella bacteria are naturally occurring in fresh water sources. The organism can multiply in man-made water systems such as cooling towers, decorative fountains, hot tubs, and large building plumbing systems.
Legionellosis is a mandatory reportable disease in Michigan. The MDHHS requests that all clinical Legionella isolates be submitted to the MDHHS Bureau of Laboratories for additional testing and isolate storage. Please note that only cultures can be used to help identify a potential source as they can be compared with environmental samples. It is important that you report cases of Legionnaires’ disease within 24 hours to the appropriate local health department. By reporting this information, local health departments can initiate investigations to identity possible sources and prevent additional disease.
If you have any questions about legionellosis please call your local health department or refer to the CDC Legionella website at: www.cdc.gov/legionella.
MDHHS press release to follow.