News Release
July 2, 2012
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Health officials urge Minnesotans to take steps to prevent illness from swimming this summer

Germs on and in swimmers' bodies can make people sick; action steps can prevent illness

As temperatures rise and Minnesotans flock to swim at their favorite beaches and pools, state health officials are reminding residents of steps they can take to help prevent recreational water illnesses this summer.

"Germs on and in swimmers' bodies end up in the water and can make other people sick," said Trisha Robinson, an epidemiologist specializing in waterborne diseases with the Minnesota Department of Health (MDH). "Even healthy swimmers can get sick from recreational water illnesses, but the young, elderly, pregnant women and people with weakened immune systems are especially at risk."

The best way to prevent recreational water illnesses is to keep germs out of the water in the first place. Swimmers can take an active role in protecting themselves and other swimmers. Follow these steps for a safe and healthy swimming experience:

    • Don't swim when you have diarrhea.
    • Don't swallow pool or lake water.
    • Practice good hygiene. Shower with soap before swimming.
    • Wash your hands thoroughly after using the toilet or changing diapers.
    • Take children on bathroom breaks or change diapers often.
    • Change diapers in a bathroom, not at poolside or beachside.

    From 2000 to 2011, 24 swimming pool outbreaks and 15 beach outbreaks were identified in Minnesota, resulting in over 900 people who became sick. The most common symptom of recreational water illness is diarrhea, which frequently is severe enough to result in hospitalization. Symptoms may not begin until a week or more after swimming.

    The parasite Cryptosporidium, one of the most common waterborne disease agents, is a chlorine-resistant parasite that can survive and be transmitted even in a properly maintained pool. So practicing healthy swimming behaviors is especially important for preventing this illness.

    If warm weather persists such that water temperatures climb into the 80s, swimmers should be aware of a different but rare kind of risk. The ameba Naegleria fowleri multiplies in stagnant freshwater lakes, ponds, streams, and rivers when water temperatures exceed 86 degrees F. It causes a very rare but fatal infection called primary amebic meningoencephalitis. This infection happens when Naegleria gets in the nose and travels to the brain. Forty cases were reported in the United States from 2001 through 2011. The only confirmed case of this infection in Minnesota was reported in August of 2010.

    "The risk of infection from Naegleria in Minnesota is very low," Robinson said. "Swimming is a very healthy summertime activity and we do not want to discourage people from swimming. Rather, simply avoid swimming, diving or other activities in obviously stagnant water when temperatures are high and water levels are low," she said.

    Some additional precautions you can take while swimming during extremely warm periods include keeping your head out of the water, using nose clips or holding the nose shut, and avoid stirring up sediment at the bottom of shallow freshwater areas.

    For more information about Healthy Swimming, see the MDH Recreational Water Illnesses Web page at or the Centers for Disease Control and Prevention Healthy Swimming Web page at


For more information, contact:

Doug Schultz
MDH Communications

Trisha Robinson
MDH Epidemiologist