![A man floats in Cruiser Bay at Big Island in Lake Minnetonka, MN on July 19, 2013. ] JOELKOYAMA•joel koyama@startribune Three cases of E. coli have been found in swimmers at Big Island in Lake Minnetonka, and the state health department has issued its seasonal warning to swimmers. One person was hospitalized but all have recovered. We're checking to see if any beaches have been closed. Bacterial outbreaks like this become pretty common in the summer, as water temperatures rise and crud gets wa](https://arc.stimg.co/startribunemedia/OEM2ROJIZWA37KODJPTAY7RPSQ.jpg?&w=1080)
Three swimmers contracted E. coli infections from water near Big Island in Lake Minnetonka during the July 4th weekend, prompting state health officials to issue summer health precautions for Minnesotans who swim outdoors.
One of the three swimmers was hospitalized, but all three have since recovered, the state Health Department said.
All beaches on Lake Minnetonka remain open and have passed regular water-quality tests, official said.
The incident marked the first case of a waterborne infection this year, but state health officials say more are likely to come.
Minnesota reported a record number of waterborne illnesses last summer, with 11 cases, but this is only the fourth E.coli outbreak since 2001.
E. coli, a bacteria that normally lives in the small intestines of humans and animals, can cause diarrhea and stomach cramps, which can be severe in some cases. Even a small amount of human or animal waste can introduce the bacteria to a swimming area, and ingesting even a small amount of tainted water can produce an infection. People typically fall ill within two to five days of swimming in contaminated water.
Health Department officials said an adult typically swallows about a tablespoon of water while swimming in a lake — enough to transmit E. coli if the water is contaminated — and children swallow much more.
The source of the bacteria in Lake Minnetonka is unknown, but lakes can be contaminated through animal droppings, sick swimmers, improper disposal of boat waste and other sources.
![A man floats in Cruiser Bay at Big Island in Lake Minnetonka, MN on July 19, 2013. ] JOELKOYAMA•joel koyama@startribune Three cases of E. coli have been found in swimmers at Big Island in Lake Minnetonka, and the state health department has issued its seasonal warning to swimmers. One person was hospitalized but all have recovered. We're checking to see if any beaches have been closed. Bacterial outbreaks like this become pretty common in the summer, as water temperatures rise](https://arc.stimg.co/startribunemedia/5JC6SDRJNDQ5LTWUTAGZX3IPDI.jpg?&w=1080)
![Boaters and swimmers at Cruiser Bay at Big Island in Lake Minnetonka, MN on July 19, 2013. ] JOELKOYAMA•joel koyama@startribune Three cases of E. coli have been found in swimmers at Big Island in Lake Minnetonka, and the state health department has issued its seasonal warning to swimmers. One person was hospitalized but all have recovered. We're checking to see if any beaches have been closed. Bacterial outbreaks like this become pretty common in the summer, as water temperatu](https://arc.stimg.co/startribunemedia/ODRAQ76OSHLE5U2RTPCFPC6ZQE.jpg?&w=1080)
