Health, Minneapolis parks officials close Lake Nokomis beaches after E. coli outbreak identified

The Minnesota Department of Health today confirmed three cases of a strain of Shiga toxin-producing Escherichia coli, or STEC, in three children who swam at Lake Nokomis beaches in Minneapolis in late July or early August. Waterborne disease specialists with MDH recommended that the lake’s beaches be closed until further notice while staff assess if there is any ongoing risk to the public. Officials with the Minneapolis Parks and Recreation Board took immediate action to close the beaches.

The children became ill between August 2 and August 5 after swimming at the lake between July 26 and August 2. None have been hospitalized.

“This is the first report of people getting ill from swimming in Minneapolis lakes we have had in more than two decades,” said Minneapolis Park and Recreation Board Superintendent Board Al Bangoura. “We take this news very seriously and are working closely with the Minnesota Department of Health as they conduct their investigation.”

State health officials said it’s possible that there are people who were exposed to E. coli at Lake Nokomis who became infected but have not yet become ill or have not yet seen a health care provider. “This strain of E. coli can lead to serious illness,” said Trisha Robinson, waterborne disease supervisor of MDH. “We encourage anyone who swam recently at Lake Nokomis and has symptoms of E. coli to contact their health care provider.”

Park staff is contacting swim lesson participants and organizers of lake events held since late July to encourage them to contact the MDH if they have been sick.

Symptoms of illness caused by STEC typically include stomach cramps and diarrhea, often with bloody stools, but only a low-grade or no fever. People typically become ill two to five days after exposure, but this period can range from one to eight days. Most people recover in five to 10 days. However, STEC infections sometimes lead to a serious complication involving kidney failure called hemolytic uremic syndrome, or HUS. Those most at risk of developing complications from STEC include children younger than 10, the elderly, and those with weakened immune systems.

Diarrhea associated with STEC infections should NOT be treated with antibiotics, as this practice might promote the development of HUS. Anyone who believes they may have developed a STEC infection should contact their health care provider.

The MDH and MPRB are asking anyone who visited Lake Nokomis, regardless of if they got sick, to complete a brief MDH online survey. If the public has any questions, they may call the Foodborne and Waterborne Illness Hotline at 651-201-5655.

The type of E. coli that caused the reported illnesses at Lake Nokomis was most likely introduced into the water by an ill swimmer. These types of contamination events are unlikely to be detected during routine beach monitoring tests. The MPRB conducts weekly beach testing for water quality and posts results online, in the water quality tab of each beach. Weekly testing has not indicated high levels of E. coli at either of the Lake Nokomis beaches. The elevated E. coli levels reported by the MPRB at other MPRB beaches is commonly caused by rain, stormwater runoff or waterfowl, not humans.

“This is also an important reminder that anyone who is experiencing diarrhea should not go swimming while they are sick,” Robinson said.

More information on STEC and how to prevent it can be found on the MDH E. coli website.