The Minnesota Department of Health is warning the public of three E. coli infections in people who swam at a popular gathering spot for swimmers in Lake Minnetonka.
The three patients all have a strain of 0157:H7 with identical DNA fingerprints, indicating they came from a single source. All are young adults and swam in the Big Island area on July 4th. One person was hospitalized, but has since been released, the Star Tribune reported.
Officials don't know what the source of contamination is, but the bacteria can come from animal waste, leaky septic systems, sewage spills, or improper waste disposal. People can also contract the illness from other sick swimmers. Health officials advise swimmers to never consume lake water as one step to avoid bacterial infections.
All public swimming areas on the lake remain open.