Recreational Water Illnesses (RWIs)

Recreational water illness (RWIs) facts

*Recreational water illness facts Medically Edited by: Melissa Conrad Stöppler, MD

  • Contrary to popular belief, chlorine does not kill all germs instantly. There are germs today that are very tolerant to chlorine and were not known to cause human disease until recently. Once these germs get in the pool, it can take anywhere from minutes to days for chlorine to kill them. Swallowing just a little water that contains these germs can make you sick.
  • Recreational water illnesses (RWIs) are caused by germs spread by swallowing, breathing in mists or aerosols of, or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. RWIs can also be caused by chemicals in the water or chemicals that evaporate from the water and cause indoor air quality problems.
  • RWIs include a wide variety of infections, including gastrointestinal, skin, ear, respiratory, eye, neurologic, and wound infections. The most commonly reported RWI is diarrhea. Diarrheal illnesses are caused by germs such as Crypto (short for Cryptosporidium), Giardia, Shigella, Norovirus and E. coli O157:H7.
  • In the past two decades, there has been a substantial increase in the number of RWI outbreaks associated with swimming. Crypto, which can stay alive for days even in well-maintained pools, has become the leading cause of swimming pool-related outbreaks of diarrheal illness.
  • Although Crypto is tolerant to chlorine, most germs are not. Keeping chlorine at recommended levels is essential to maintain a healthy pool. A 2010 study found that 1 in 8 public pool inspections resulted in pools being closed immediately due to serious code violations such as improper chlorine levels.
  • With RWI outbreaks on the rise, swimmers need to take an active role in helping to protect themselves and prevent the spread of germs. It is important to learn the basic facts about RWIs so you can keep yourself and your family healthy every time you swim.
  • Knowing the basic facts about recreational water illnesses (RWIs) can make the difference between an enjoyable time at the pool, beach, or water park, and getting a rash, having diarrhea, or developing other, potentially serious illnesses.
Medically Reviewed by a Doctor on 4/7/2014

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Recreational Water Illnesses - Sources Question: If known, where did you contract your recreational water illness (RWI)? Please share your experience.
Recreational Water Illnesses - Chlorine Question: What types of pool chemicals do you use? Has anyone ever gotten an RWI from your pool or spa?
Recreational Water Illnesses - Prevention Question: In what ways do you try to prevent RWIs? Please describe your experience.