Enjoy Healthy Swimming! Enjoy Healthy Swimming!
Centers for Disease and Prevention

Recreational water illnesses (RWIs) are spread by swallowing, inhaling, or having contact with contaminated water from swimming pools, spas, lakes, rivers, or oceans1. The most commonly reported RWI is diarrhea caused by pathogens such as Cryptosporidium, Giardia, Shigella, and Escherichia coli O157:H7.

Children, pregnant women, and persons with compromised immune systems are at greatest risk for infection with these waterborne germs. Infection with Cryptosporidium can be life threatening in persons with weakened immune systems2. Other RWIs can cause various conditions, including skin, ear, eye, respiratory, wounds, and neurologic infections. Visit CDC’s Healthy Swimming Web site at http://www.cdc.gov/healthyswimming for further information on RWIs.

• Understanding the Spread of RWIs

• Chlorine-resistant germs

• Poorly maintained pools

• Low public awareness

• Improving Prevention Efforts

• Public Health Agencies

• Aquatics Operators

• General Public

• At Lakes, Rivers, and the Ocean

Understanding the Spread of RWIs
Approximately 30,000 recreational water illnesses were documented in the U.S. from 1978–2004, with a steady increase in reported outbreaks3. This increase is probably the result of a combination of increased water usage, improved outbreak detection, and increased disease transmission. The spread of RWIs is facilitated by:

• Chlorine-resistant germs

• Poorly maintained pools

• Low public awareness

Chlorine-Resistant Germs
Much of the increase in the number of reported outbreaks of diarrhea can be attributed to chlorinated pools3. The parasite Cryptosporidium is the leading cause of outbreaks of diarrheal illness associated with swimming pool use (62% from 1995–2004). Unlike other organisms, which are more susceptible to the levels of chlorine typically found in a pool, Cryptosporidium is chlorine-resistant. As a result, even well-maintained pools can spread illness. Supplementary disinfection systems (e.g., ultraviolet light or ozone systems) can inactivate the parasite.

Poorly Maintained Pools
Approximately one-fourth of diarrheal RWI outbreaks that occur in pools are caused by chlorine-sensitive germs such as E. coli O157:H7 and Shigella. Many pool-associated skin, ear, eye, respiratory, wound and neurologic infections are also caused by chlorine-sensitive germs. These outbreaks clearly implicate poor pool maintenance as the cause, since proper disinfection would have prevented them. Analysis of 2002 pool inspection data from six sites across the United States determined that the majority of pools had one or more violations. One in 11 pools were closed immediately for public health reasons4.

Low Public Awareness
CDC conducted focus groups with parents of young children and found a general lack of awareness about RWIs among the public. Parents have virtually no knowledge of RWIs and their spread through swimming venues. In fact, many people think of chlorinated pool water as sterile environments. This lack of awareness likely results in behaviors (swimming while ill with diarrhea, swallowing of pool water, poor hygiene) that contribute to the spread of diarrheal RWIs5.

Improving Prevention Efforts

Public Health Agencies
Public health agencies and officials are encouraged to become involved in Recreational Water Illness Prevention Week by engaging the public, local aquatic operators, and the media in prevention efforts. Suggestions on how to promote healthy swimming are available at http://www.cdc.gov/healthyswimming/tools.htm

Aquatics Operators
Aquatics managers, operators, and staff can become involved by engaging swimmers and the media in prevention efforts. Find prevention brochures, posters, and information for the public at http://www.cdc.gov/healthyswimming/health_materials.htm. Access pool operation information at http://www.cdc.gov/healthyswimming/fecal_response.htm#a and prevention recommendations at http://www.cdc.gov/healthyswimming/prevention_materials.htm

General Public
Raising awareness about RWIs is key to preventing the spread of RWIs. Follow the “Six Pleas” for Healthy Swimming to stop germs from causing illness at the pool:

• Please don’t swim when you have diarrhea.

• Please don’t swallow the pool water.

• Please take your kids on bathroom breaks or check diapers often.

• Please change diapers in a bathroom and not at poolside.

• Please wash your child thoroughly (especially the rear end) with soap and water before swimming.

Further swimmer protection information can be found at: http://www.cdc.gov/healthyswimming/swimmer_protection.htm

At Lakes, Rivers and the Ocean
When visiting natural waters, consider recommendations from the Environmental Protection Agency:

• Ask if your local beach water quality is monitored. If so, check out the latest results. (http://www.cdc.gov/healthyswimming/beaches_rivers.htm)

• Avoid swimming after a heavy rain

• Look for storm drains (pipes that drain polluted water from streets) along the beach. Don’t swim near them.

• Look for trash and other signs of pollution such as oil slicks in the water. These kinds of pollutants may indicate the presence of disease causing microorganisms that may also have been washed into the water.

Access EPA’s brochure “Before You Go to the Beach” at http://www.cdc.gov/healthyswimming/pdf/epa_beachbro.pdf