What are Recreational Water Illnesses (RWIs)?
RWIs are illnesses that are spread by swallowing, breathing, or having contact with contaminated water from swimming pools, spas, lakes, rivers, or oceans. Recreational water illnesses can cause a wide variety of symptoms, including gastrointestinal, skin, ear, respiratory, eye, neurologic and wound infections. The most commonly reported RWI is diarrhea. Diarrheal illnesses can be caused by germs such as Crypto, short for Cryptosporidium, Giardia, Shigella, norovirus and E. coli O157:H7.
Where are RWIs found?
RWIs can be spread through use of swimming pools, hot tubs, decorative water fountains, oceans, lakes, and rivers.
Swimming Pools, Waterparks, Spray Features
The most common illness spread through use of swimming pools is diarrhea. If swimmers are ill with diarrhea, the germs that they carry can contaminate the water if they have an “accident” in the pool. On average, people have about 0.14 grams of feces on their bottoms which, when rinsed off, can contaminate recreational water. When people are ill with diarrhea, their stool can contain millions of germs. Therefore, swimming when ill with diarrhea can easily contaminate large pools or waterparks. As a result, if someone swallows water that has been contaminated with feces, he/she may become sick. Many of these diarrhea-causing germs do not have to be swallowed in large amounts to cause illness. Remember that standing water is not necessary for RWIs to spread so even spray decks can become contaminated (the water is just in a collection tank underground) and spread illness. To ensure that most germs are killed, chlorine or other disinfectant levels and pH should be checked regularly as part of good pool operation.
Hot Tubs
Skin infections like “hot tub rash” are the most common RWIs spread through hot tubs and spas. Chlorine and other disinfectant levels evaporate more quickly because of the higher temperature of the water in the tubs. Respiratory illnesses are also associated with hot tub use if the hot tub is not well maintained. Because of this it is important to check disinfectant levels even more regularly than in swimming pools. “Hot tub rash” can also be spread in pools and at the lake or beach.
Decorative Water Fountains
Not all decorative or interactive fountains are chlorinated or filtered. Therefore, when people, especially diaper-aged children, play in the water, they can contaminate the water with fecal matter. Swallowing this contaminated water can then cause diarrheal illness.
Lakes, Rivers, and Oceans
Lakes, rivers, and oceans can become contaminated with germs from sewage, animal waste, water runoff following rainfall, fecal accidents, and germs rinsed off the bottoms of swimmers. It is important to avoid swallowing the water because natural recreational water is not disinfected. Avoid swimming after rainfalls or in areas identified as unsafe by health departments. Contact your state or local health department for results of water testing in your area or go to EPA’s beach site or their National Health Protection Survey of Beaches.
How are RWIs spread?
Keep in mind that you share the water with everyone else in the pool, lake, or ocean.
Diarrheal Illnesses
If swimmers are ill with diarrhea, the germs that they carry can contaminate the water if they have an “accident” in the pool. On average, people have about 0.14 grams of feces on their bottoms which, when rinsed off, can contaminate recreational water. When people are ill with diarrhea, their stool can contain millions of germs. Therefore, swimming when ill with diarrhea can easily contaminate large pools or waterparks. In addition, lakes, rivers, and the ocean can be contaminated by sewage spills, animal waste, and water runoff following rainfall. Some common germs can also live for long periods of time in salt water.
So, if someone swallows water that has been contaminated with feces, he/she may become sick. Many of these diarrhea-causing germs do not have to be swallowed in large amounts to cause illness.
Other RWIs
Many other RWIs (skin, ear, eye, respiratory, neurologic, wound, and other infections) are caused by germs that live naturally in the environment (water, soil). In the pool or hot tub, if disinfectant is not maintained at the appropriate levels, these germs can increase to the point where they can cause illness when swimmers breathe or have contact with water containing these germs.
For more details on RWIs see the Centers for Disease Control Healthy Swimming Web site.
