Swimming and Recreational Water Precautions

A variety of infections (e.g., skin, ear, respiratory, and diarrheal infections) have been linked to wading or swimming in the ocean, freshwater lakes and rivers, and swimming pools, particularly if the swimmer's head is submerged. Water can be contaminated by other people and from sewage, animal wastes, and wastewater run-off. Diarrhea and other serious waterborne infections can be spread when disease-causing organisms from human or animal feces are introduced into the water. Travelers who swim should be advised to avoid beaches that may be contaminated with human sewage or dog feces.

Accidentally swallowing small amounts of fecally contaminated water can cause illness. Travelers should be warned to try to avoid swallowing water while engaging in aquatic activities. Generally, for infectious disease prevention, pools that contain chlorinated water can be considered safe places to swim. However, some organisms (e.g., Cryptosporidium, Giardia, hepatitis A, and Norwalk virus) have moderate to very high resistance to chlorine levels commonly found in chlorinated swimming pools, so travelers also should avoid swallowing chlorinated swimming pool water. All travelers should refrain from swimming during episodes of diarrhea to avoid contaminating recreational water.

Travelers should be advised to avoid swimming or wading with open cuts or abrasions that might serve as entry points for pathogens. In certain areas, fatal primary amebic meningoencephalitis has occurred after swimming in warm freshwater lakes or rivers, thermally polluted areas around industrial complexes, and hot springs so avoid submerging one's head and wear nose plugs when entering untreated water to prevent water getting up the nose. Travelers should also be advised to avoid wading or swimming in freshwater streams, canals, and lakes in schistosomiasis-endemic areas of the Caribbean, South America, Africa, and Asia (see Map 3-8. Geographic distribution of schistosomiasis), or in bodies of water that may be contaminated with urine from animals infected with Leptospira. Biting and stinging fish, corals, and jellyfish can also be hazardous. Travelers should be advised never to swim alone or when under the influence of alcohol or drugs. Likewise, they should never dive or jump into an unfamiliar body of water without first determining the depth (at least 9 feet for jumping and diving) and the terrain, and whether there are any hidden obstacles. Travelers should be advised to learn cardiopulmonary resuscitation (CPR) and basic first-aid. They should be aware of the weather conditions and forecasts. Thunderstorms or even strong winds are dangerous for swimmers and boaters. A personal flotation device (life jacket) should always be worn when boating, skiing, or using personal watercraft regardless of the distance to be traveled, the size of the boat, or swimming ability. Travelers should be reminded that open water usually has limited visibility, and conditions can sometimes change from hour to hour. Currents are often unpredictable, moving rapidly and quickly changing direction. A strong water current can carry even expert swimmers far from shore.

— Michael Beach, Christene Branche, Timothy Davis