June 28, 2011
Health officials remind Minnesotans to practice healthy swimming behaviors this summer
Germs on and in swimmers' bodies can make people sick; actions steps can prevent illness; caution recommended regarding swimming in stagnant or low freshwater when temperature rises
Awareness of illness and healthy swimming behaviors play an important role in stopping the spread of illnesses through recreational water, according to the Minnesota Department of Health (MDH).
"Germs on and in swimmers' bodies end up in the water and can make other people sick," said Dr. Kirk Smith, epidemiology supervisor for MDH. "Even healthy swimmers can get sick from recreational water, 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. 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 2010, 23 swimming pool outbreaks and 15 beach outbreaks were identified in Minnesota, resulting in over 900 illnesses. 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. That's why it's so important to follow the steps above to prevent spreading the illness, health officials said.
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 free-living ameba Naegleria fowleri, proliferates 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. Thirty cases were reported in the United States from 2000 through 2009. The first confirmed case of this infection in Minnesota was reported in August of 2010. This infection happens when Naegleria gets in the nose and travels to the brain.
"The risk of infection from Naegleria in Minnesota is very low," Smith 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," he said.
Some additional precautions one could 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 Centers for Disease Control and Prevention (CDC) Healthy Swimming Web page at http://www.cdc.gov/healthywater/swimming/.