Lake Minnetonka Conservation District

Hot Topics


Big Island Illness Investigation Update 07/11/2019

The Hennepin County Public Health Department is investigating reports of illness from people who were boating at Big Island over the 4th of July. As of July 10, 2019, the County reported 140 calls, with 116 meeting the case definition of vomiting and diarrhea. The results of the testing from the Minnesota Department of Health is anticipated this week. In the meantime, we are not speculating as to the cause or source. Once the test results are received and the investigation is complete, we will follow up with the county regarding the findings and an update will be provided in the future.

It is unfortunate that some people that recreated on the lake over the 4th of July holiday reported becoming ill. We want everyone to be safe and healthy while enjoying the lake, which is why certain regulations and measures are in place. Our office has received some questions and thought it might be helpful to clarify a couple of items in conversation with Hennepin County.

  • There is no reason to believe the lake cannot be used. Further, it is unlikely that if a pathogen was introduced and existed at the time, that it would still be present due to natural destruction and dilution. Lake Minnetonka is a large lake, 14,000 acres and 42 bays, and the area in question is a small part of the lake.
  • The closure of the Excelsior beach is not related to the illness investigation at Big Island. These are two separate actions. It is not related to the closure of other lakes in Minnesota either. The closure of the beach was due to higher than recommended levels of E coli, an indicator used to determine safe water quality for people to swim and play in the water. It is not uncommon to have the beaches closed periodically through the summer. LMCD posted beach testing information under common resources on the website last year due to calls.
  • The CDC recommends waiting at least 24 hours after a heavy rainfall due to possible contaminants in runoff from land. More beach safety tips are provided below.
  • Large gatherings, whether on land or water, carry a higher risk of exposure to illnesses and are also more likely to result in epidemiological investigations since people are more likely to report their illnesses. There are several ways that illnesses can be transmitted- person-to-person, through food, water, animals, etc. This makes the epidemiological investigations more complex.
  • The illnesses appear to be self-limited meaning people who are sick typically feel better in a couple of days. It is important to drink fluids to counteract dehydration. People who do not feel better or in severe cases should contact their physician.

Tips for staying healthy at the beach

Bacteria and viruses in the water can cause some ear and eye infections, stomachaches, diarrhea, and flu-like symptoms. Hennepin County and the Centers for Disease Control has the following recommendations for staying healthy while enjoying the beach:

  • Wait 24 hours to swim after a heavy rainfall.
  • Shower after being at the beach.
  • Don’t mouth or swallow water.
  • Wash your hands thoroughly before eating and after using the bathroom.
  • Don’t swim if you’re sick, or have a weakened immune system.
  • Put tight-fitting rubber or plastic pants on children who are wearing diapers and those who are not toilet-trained.
  • Take your children for frequent bathroom breaks.
  • Don’t attract waterfowl to the beach by feeding ducks, geese, gulls, etc.
  • Pick up your trash.
  • If you boat, properly dispose of waste.
Posted on: July 11th, 2019