Common Recreational Water Illnesses and How to Prevent Them

Most of the time swimming is safe, but there's a small chance of getting sick from swimming in contaminated water. Recreational water illness (RWI) consists of a variety of waterborne infections that can affect many different organ systems in your body; most commonly causing diarrhea. Since the 1990s, there has been an increase in RWIs; with water-related illnesses on the rise, comes an increased need for awareness among swimmers and other people involved in recreational water use.

Three kids jumping into a lake

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Common Symptoms

  • Diarrhea: The most common RWI symptom is diarrhea. Diarrhea can be caused by cryptosporidium (commonly known as "crypto") and escherichia coli (E. coli).
  • Hot tub rash or dermatitis: These rashes are usually raised, red and itchy. The most severely affected areas are often those that were not covered by a bathing suit. The most common germ that causes a hot tub rash is pseudomonas aeruginosa.
  • Ear pain: Pseudomonas aeruginosa can also cause swimmer's ear (otitis externa). Swimmer's ear can occur in adults and children but is more common in children. Along with ear pain, other common symptoms include inflammation (redness), itchiness inside the ear canal and ear drainage.
  • Upper respiratory symptoms: These can include cough, sinus congestion, or influenza-like symptoms. They are less common, but potentially more serious. Severe pneumonia from Legionella (legionnaires' disease) may be life threatening and should be treated with antibiotics.

How Recreational Water Illnesses Are Contracted

Recreational water illnesses happen when you accidentally swallow, inhale, or get water in your ears that contains infectious bacteria. It may possibly also occur through cuts or open sores. Contaminated water can be found in mountain streams and lakes, hot tubs, public pools or water parks, and oceans—just about any recreational source of water you can identify.

One thing that is important to understand is that chlorine does not immediately kill RWI germs. Also, warm water in hot tubs may promote bacterial growth and water aeration may deplete chlorine levels. ”Once the water source is contaminated, it can take chlorine minutes or even days to kill the contaminant. Even a little contact with the germ can cause you to become sick. You will be at most risk of contracting an RWI if you are a child, pregnant, or have a weakened immune system (organ transplant, HIV, or have undergone chemotherapy).

Recreational water Illnesses are not typically spread from person to person through direct contacts, such as physical touch, kissing or most sexual contact. It is not possible, for example, to give swimmer's ear to someone else. However, you can transmit diarrhea-causing parasites through fecal matter if you don't wash your hands after using the restroom. Rashes acquired in hot tubs and swimming pools are generally not contagious. However, if you have diarrhea and then get in a swimming pool you will contaminate the water, making it much more likely that someone else will develop an RWI.

Some illnesses such as methicillin-resistant Staphylococcus aureus (MRSA) do not live long in chlorinated water and are more likely to be passed from person to person through indirect contact, such as using the same towel or by touching other shared objects. This doesn't really count as a true RWI.


Some recreational water illnesses can be treated with antibiotics or antifungal medications, while others will go away on their own and only require symptom management to provide comfort or prevent dehydration. Swimmer's ear is treated with antibiotic drops or acetic acid drops that must be put inside the ear. Seeking medical attention at the onset of symptoms can ensure that you receive the proper medical treatment for your illness and avoid serious complications. The length of the infection will vary by the germ causing it and whether or not antibiotics or anti-fungal medications can be used.


Prevention is very important. With the exception of swimmer's ear, which is easier to prevent than some of the other RWIs, you may not always have the ability to prevent acquiring an RWI. You should, however, do all you can to prevent spreading these infections, which will decrease the incidence of RWIs and subsequently your chances of getting one. Listed below are some generalized prevention techniques:

  • Shower (preferably with soap) before and after swimming, and practice good hand hygiene.
  • Check and maintain proper chlorine levels in personal swimming pools and hot tubs.
  • Don't go swimming when you or a family member has diarrhea. Most pools recommend waiting two weeks before swimming after you've had a diarrhea-causing illness.
  • Take your children regularly to the bathroom when using recreational water facilities. Children who are not potty trained should wear a certified swim diaper plus plastic pants.
  • Don't swallow pool water or drink untreated natural water (e.g., stream water).
  • Don't get into a swimming pool or hot tub if you have open cuts or sores.
  • Dry your ears out well or wear earplugs to keep your ears dry while showering or swimming.

If you suspect you have gotten sick from swimming see a medical professional as soon as possible.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  • Diarrheal Illness. CDC website. Updated
  • Ear Infections. CDC website.
  • Recreational Water Illnesses. CDC website. Updated January 25, 2017.