Recreational Water Illnesses (RWIs)

Minnesota Department of Health
Revised May, 2009

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What are recreational water illnesses?

Recreational water illnesses (RWIs) are illnesses that are spread by swallowing or having contact with contaminated water from swimming pools, hot tubs, lakes, oceans, or rivers. RWIs cause a wide variety of symptoms, but the most commonly reported is diarrhea. Diarrheal RWIs can be caused by germs such as Cryptosporidium, Giardia, norovirus, Shigella, and E. coli O157:H7.

Where are RWIs found?

RWIs can be spread through use of swimming pools, hot tubs, splash parks, decorative fountains, lakes, rivers, and oceans.

What are common causes of RWIs?

  • Cryptosporidium
  • E. coli O157:H7
  • Giardia
  • Norovirus
  • Shigella
  • Pseudomonas Dermatitis “Hot Tub Rash”
  • Otitis Externa “Swimmer’s Ear”

How are RWIs spread?

When people are ill with diarrhea, even a speck of their stool can contain millions of germs. Swimming while ill can easily contaminate the water – even if you don’t have an accident. Also, lakes and rivers can be contaminated by animal waste, sewage spills, and water runoff following rainfall. If someone swallows water that has been contaminated, he/she may become sick.

Other non-diarrheal RWIs are caused by germs that live naturally in the environment (water, soil). If disinfectant is not adequately maintained at the appropriate levels in a pool or hot tub, these germs can increase to the point where they cause illness when swimmers breathe or have contact with the water.

What are the symptoms?

Symptoms of a diarrheal RWI can include diarrhea (sometimes bloody), vomiting, stomach cramps, loss of appetite, weight loss, and fever. Other RWIs can cause skin, ear, eye, and respiratory symptoms.

What should I do if I have symptoms?

  • Contact your health care provider.
  • Wash your hands often.
  • Do not swim while you have diarrhea. If you are diagnosed with Cryptosporidium, you should not swim for 2 weeks after your diarrhea has stopped.

Healthy Swimming Tips:

  • Do not swim while you have diarrhea. You can spread germs in the water and make other people sick.
  • Take a shower before and after swimming. Germs on your body end up in the water.
  • Wash your child thoroughly before swimming (especially the rear end). Everyone has invisible amounts of fecal matter on their bottoms that ends up in the pool.
  • Do not swallow water or get water in your mouth while swimming.
  • When swimming, take kids on frequent bathroom breaks – waiting to hear “I have to go” may mean that it’s already too late.
  • Change diapers in changing rooms, not poolside or on the beach. Wash your hands after changing diapers.


Updated Tuesday, July 22, 2014 at 12:48PM