We don’t have a lot to worry about in the waters here in Minnesota: No sharks, no piranhas, no eels, or other things in the water looking to take a bite out of you. Well, there was that incident in Duluth with the muskie, but things like that don’t happen often here other than maybe a Sunfish or Blue Gill nipping at your toes.
But there are a few things we do have to worry about, and that everyone should be aware of: Whatever germs are on your body can end up in the water and make other people sick (after all, lakes and the such are basically enormous fish bathtubs and toilets).
Swimmers can protect themselves though with some common sense and a couple rules:
1. If you have diarrhea stay out of the water
2. If possible shower before you get in the water
3. Don’t drink the water (see above bath tub/toilet comment)
Trisha Robinson, Waterborne Diseases Unit Supervisor for the Minnesota Department of Health, had this to say about preventing illnesses:
“Swimming is a healthy, fun summertime activity. We each need to do our part to keep the water healthy for everyone to enjoy.”
How often do people actually get sick? In Minnesota, from 2007 to 2016, there were 49 reported outbreaks tied to recreational water. This includes beaches, pools, and splash pads, resulting in 730 known illnesses. Cryptosporidium was responsible for 55% of the outbreaks, and was the largest proportion. Cryptosporidium is a chlorine-resistant parasite that can survive and spread even when a pool or splash pad is properly maintained.
And the most common symptom of an illness? Go back to rule number one: diarrhea. These symptoms may not even show up until a week or more after you had your fun in the water, and can sometimes be so severe that a hospital visit is required.
There is another baddie that can be in the water also: This organism prefers warmer waters, so it is important to be aware of this as Minnesota’s lakes warm up in the summer. Naegleria fowleri is rare, but very, very serious. It’s an ameba found in freshwater and soil and appears when prolonged periods of hot weather result in higher water temperatures and lower water levels.
Infection with Naegleria fowleri causes a very rare infection called Primary Amebic Menigoencephalitis (PAM), and is nearly always fatal. It infects people by entering in through the nose. Water entering through the nose normally happens when people are in warm freshwater while swimming and diving. Symptoms of PAM typically start about five days after infection, starting out mild and worsening in a short amount of time. If, after being in warm freshwater within the previous two weeks, someone has a sudden fever, headache, stiff neck or vomiting seek medical attention immediately.
Robinson had this to say about lowering the risk of infection by Naegleria fowleri:
“We encourage all swimmers to be informed of the risk of Naegleria fowleri and take steps to reduce their risk. Swimmers should assume that Naegleria fowleri is present in warm freshwater and there will always be a low level of risk when entering these waters. Taking steps to limit the amount of freshwater that goes up your nose will reduce your risk.”
Here are some tips for limiting the amount of water that would go up your nose while swimming or diving;
1. When the temperature is high and water level is low, avoid warm freshwater lakes, rivers, and other bodies of water.
2. Avoid putting your head underwater
3. Hold your nose shut or use nose clips
4. Avoid digging or stirring up the sediment on the bottom in shallow, warm freshwater areas
Further reading: MDH Press Release
For more information on healthy swimming and preventing illness, go to MDH’s Preventing Recreational Water Illnesses website.
For information on Minnesota Beaches, please visit the DNR Swimming Beaches website.