Why Diarrhea & Swimming Don’t Mix

The summer swim season is here, and millions of Americans will be flocking to local pools for fun in the sun and exercise. However, swimming, like any form of exercise, does not come without health risks. The good news is that we can all take a few simple but effective steps to help keep ourselves and family and friends healthy and safe.

While sunburn and drowning might be the health risks that first come to mind when you think about swimming, diarrhea is another culprit. Outbreaks of diarrheal illness linked to swimming are on the rise. And this Healthy and Safe Swimming Week, we want to make sure you know these important facts about diarrhea-causing germs and how to protect yourself and loved ones.

1. When swimmers have diarrhea in the water, they release diarrhea-causing germs into the water. For example, a swimmer infected with the parasite Cryptosporidium can release 10–100 million germs into the water. Swallowing 10 or fewer Cryptosporidium germs can make you sick.
2. Some diarrhea-causing germs can survive in properly treated water for days. Standard levels of chlorine and other disinfectants can kill most germs in swimming pools within minutes. However, Cryptosporidium has a tough outer shell and can survive for more than 7 days in properly treated water. During 2000-2014, the majority of outbreaks linked to pools, hot tubs, or water playgrounds were caused by the parasite Cryptosporidium.
3. Swim diapers won’t keep diarrhea out of a pool. Using swim diapers might give parents a false sense of security when it comes to containing diarrhea. Research has shown that swim diapers might hold in some solid feces but these diapers only delay diarrhea-causing germs, like Cryptosporidium, from leaking into the water by a few minutes. Swim diapers do not keep these germs from contaminating the water.
4. Don’t swallow the water you swim in. Swallowing just a small amount of water with diarrhea germs in it can make you sick for up to 3 weeks.
5. Don’t swim or let your kids swim if sick with diarrhea. We all share the water we swim in. Do your part to help keep loved ones healthy. Don’t swim or let your kids swim if sick with diarrhea.

CDC’s Michele Hlavsa is a nurse and the chief of CDC’s Healthy Swimming Program. As a parent, it is important for her to know how to protect her children from not only diarrhea, but all types of germs and injuries linked to swimming. Michele encourages swimmers to follow a few easy and effective steps each time they swim in a pool or get in a water playground this summer and year-round.