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MDHHS issues update to 2015 Legionnaires' disease report for Genesee County


LANSING, Mich. – As part of the ongoing investigation into the increase of Legionnaires’ disease (LD) in Genesee County, the Michigan Department of Health and Human Services (MDHHS) today issued an updated summary for 2015. The update includes three additional LD cases (two deaths) identified since the last report.

Legionella is a type of bacteria commonly found in the environment that grows best in warm water, such as potable water systems (hospitals, large buildings), hot tubs, cooling towers, and decorative fountains. When people are exposed to the bacteria, it can cause legionellosis, a respiratory disease that can infect the lungs and cause pneumonia. The bacteria can also cause a less serious infection called Pontiac fever. Legionella is not transmitted person to person.

“To date, 91 cases and 12 deaths have been identified in total for 2014 and 2015 in Genesee County,” said Eden Wells, M.D., Chief Medical Executive with the MDHHS. “We remain vigilant in identifying any potential case associated with the outbreak.”

All of the new cases were identified by MDHHS personnel from hospital testing data that was recently forwarded to the department. Of the three additional cases, two had not been appropriately reported to the public health system.  The third case was reported in a different jurisdiction and there was no epidemiologic information available to link it to the outbreak. MDHHS has provided additional guidance to the hospital to assist them in providing more accurate reporting moving forward.

The public health investigation has looked at a number of potential exposures that the ill people may have experienced, which included exposures to hospitals, water, and community venues. The investigation was able to identify a common source of exposure for 50 individuals (55 percent) of the 91 total confirmed cases, which is a hospital in Flint, Mich. that is served by the City of Flint municipal water system.  MDHHS cannot conclude that the increase is related to the water switch in Flint nor can we rule out a possible association at this time.

For the May 2015 to October 2015 time period, 46 LD cases and seven deaths have been confirmed in the Genesee County outbreak. Data previously indicated 43 cases and five LD-associated deaths for 2015. The number of cases for June 2014 through March 2015 time period remains unchanged with 45 LD cases confirmed, including five associated fatalities. There were no cases reported in April 2015.

MDHHS has partnered with Wayne State University and continues to work with the Genesee County Health Department (GCHD) and the Centers for Disease Control and Prevention (CDC) on enhanced surveillance for Legionnaire’s disease which will continue in 2016.