Recreational water illnesses

Summer is here, so now is the time to get out and enjoy the weather and get into the water. But don’t let all that beautiful blue water fool you; it can be contaminated with many germs that can cause recreational water illnesses (RWI).  

Knowing the basic facts about RWI can make the difference between an enjoyable time at the pool, beach, or water park, and getting a rash, having diarrhea, or developing another potentially serious illness.

Diarrhea and swimming don’t mix!

Diarrhea is the most common RWI.  Swimmers who are sick with diarrhea—or who have been sick in the last two weeks—risk contaminating pool water with germs. Certain germs that cause diarrhea can live from minutes to days in pools, even if the pool is kept clean and disinfected.  Infectious diarrhea can contain anywhere from hundreds of millions to one billion germs per bowel movement.  Swallowing even a small amount of water that has been contaminated with these germs can make you sick. Tiny amounts of fecal matter are rinsed off all swimmers’ bottoms as they swim through the water. That is why it is so important to stay out of the pool if you are sick with diarrhea. 

Many other RWI (skin, ear, eye, respiratory, neurologic, wound, and other infections) are caused by germs that live naturally in the environment (for example, in water and soil). If disinfectant levels in pools or hot tubs are not maintained at the appropriate levels, these germs can multiply and cause illness when swimmers breathe in mists or aerosols of or have contact with the contaminated water.

Oceans, lakes, and rivers can be contaminated with germs from sewage spills, animal waste, water runoff following rainfall, fecal incidents, and germs rinsed off the bottoms of swimmers. It is important to avoid swallowing the water because natural recreational water is not disinfected.

Here are a few tips on what to look for before you go swimming to help you avoid a RWI:

Before you go into the water at the beach or lake:

  •  Avoid swimming after a heavy rain.
  •  Beware of storm drains (pipes that drain polluted water); do not swim near them. 
  •  Look out for trash and other signs of pollution such as oil slicks in the water; this may indicate presence of disease-causing germs that may have washed into the water. 

Things you should notice around the pool:

  • Clean and clear pool water. You should be able to clearly see any painted stripes and the bottom of the pool. 
  • Smooth pool sides. Tiles should not be sticky or slippery. 
  • No odor. A well-chlorinated pool has little odor. A strong chemical smell indicates a maintenance problem. 
  • Pool equipment working. Pool pumps and filtration systems make noise and you hear them running.

Remember—Practice healthy swimming behaviors:

  • Don’t swim when you have diarrhea.
  • Don’t swallow or get the water from pools, lakes, rivers, or oceans in your mouth.
  • Shower before swimming.
  • Wash your hands after using the toilet or changing diapers.
  • Take children on bathroom breaks or check diapers often.
  • Change diapers in a bathroom and not at poolside and thoroughly clean the diaper changing area. 


Additional resources
Swimmer protection—Centers for Disease Control and Prevention 
Recreational water illnesses: Information for the public—Centers for Disease Control and Prevention