Grand Rapids City Water Supply Identified as Source of Legionnaires’ Outbreak

Map of approximate area where cases of Legionnaire’s disease have been confirmed in Grand Rapids

Health officials say they have identified the source of a Legionnaires’ disease outbreak in Grand Rapids.

14 cases of Legionnaires’ disease have been confirmed since April 2023. Legionnaires’ disease is a serious type of pneumonia caused by inhaling Legionella bacteria found in water.

Likely case exposures have been geographically clustered in homes and other buildings in the area north of Golf Course Road/SE 10th Street, south of NE/NW 8th Street, east of 11th Avenue SW/10th Avenue NW, and west of 7th Avenue SE/8th Avenue NE.

The Minnesota Department of Health says the municipal water supply was the only common exposure reported by the people who got sick. City authorities said Monday that they plan to flush and disinfect the water system to reduce risks of the disease.

Legionella lives and grows particularly well in water that is stagnant between 70-120 degrees Fahrenheit, or when it is not treated with adequate water treatment chemicals, such as chlorine. The Grand Rapids Public Utilities water supply is one of the few community water systems in Minnesota that does not chlorinate its water because some systems that draw water from groundwater sources, such as community wells, are not required to add disinfectants.

Legionnaires’ disease can be serious and sometimes fatal. In general, about one out of every 10 people who got sick with Legionnaires’ disease dies.

Of the 14 cases associated with the Grand Rapids outbreak, all have been adults, and 11 have required hospitalization for their illness. To date, no deaths have occurred associated with this outbreak.