News release: Simple steps make for safe, healthy swimming

News Release
July 31, 2017

Contact information

Simple steps make for safe, healthy swimming

Peak of summer is also prime time for some waterborne pathogens like “Crypto” and Naegleria fowleri

Swimming and playing in lakes, rivers and pools is a favorite part of summer for many Minnesotans, and health officials remind Minnesotans to have fun and be safe by taking a few simple steps to prevent illnesses that can come from water recreation.

“Germs in and on swimmers’ bodies end up in the water and can make other people sick,” said Trisha Robinson, Waterborne Diseases Unit Supervisor for the Minnesota Department of Health (MDH). “The best way to prevent recreational water illnesses is to keep germs out of the water in the first place.”

Swimmers can protect themselves and others by following these simple steps:

  1. Stay out of the water if you have diarrhea.
  2. Shower before you get in the water.
  3. Don’t swallow the water.

From 2007 to 2016 in Minnesota, there were 49 reported outbreaks tied to recreational water, such as beaches, pools or splash pads, resulting in 730 known illnesses. The largest proportion of the outbreaks (55 percent) were caused by Cryptosporidium, a chlorine-resistant parasite that can survive and spread even in a properly maintained pool or splash pad.

The most common symptom of illness caused by germs in the water is diarrhea, which in some cases can be severe enough to result in hospitalization. Symptoms may not develop until a week or more after swimming.

“Swimming is a healthy, fun summertime activity,” Robinson said. “We each need to do our part to keep the water healthy for everyone to enjoy.”

As the temperatures in Minnesota’s lakes warm up, it’s important for swimmers to be aware of the risk of a very rare but serious infection from another organism called Naegleria fowleri. Naegleria fowleri is an ameba found in freshwater and soil. While infections with Naegleria fowleri are rare, they occur mainly when prolonged periods of hot weather result in higher water temperatures and lower water levels.

Infection with Naegleria fowleri causes a very rare but nearly always fatal brain infection called Primary Amebic Meningoencephalitis (PAM). The organism infects people by entering the body through the nose. Generally, this occurs when people interact with warm freshwater for activities such as swimming and diving.

“We encourage all swimmers to be informed of the risk of Naegleria fowleri and take steps to reduce their risk,” Robinson said. “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.”

Swimmers can reduce their risk by limiting the amount of freshwater going up the nose. Additional steps swimmers can take include:

  1. Avoid warm freshwater lakes and other water bodies when the water temperature is high and the water level is low.
  2. Avoid putting your head under water.
  3. Hold your nose shut or use nose clips.
  4. Avoid digging or stirring up the sediment in shallow, warm freshwater areas.

Symptoms of PAM usually start about five days after infection. Symptoms can be mild at first but worsen very quickly. People should seek medical care immediately whenever they have a sudden fever, headache, stiff neck and vomiting – particularly if they have been in warm freshwater within the previous two weeks.

For more information on healthy swimming, go to MDH’s preventing recreational water illnesses website.  For more information about Naegleria fowleri, visit MDH’s Naegleria website.


Media inquiries:

Doug Schultz
MDH Communications