Swallowing Water May Produce Diarrhea, Nausea, and Stomach Cramps

Summer is arriving and if you intend to visit a local swimming pool or that new water park, the Centers for Disease Control and Prevention (CDC) recommends you should be very careful.

A mouthful of swimming pool water could quickly make an healthy person sick with diarrhea, nausea, and stomach cramps.

The CDC reports diarrhea outbreaks caused by parasitic infection from swimming pools have doubled since 2014.

At least 32 outbreaks caused by Cryptosporidium (Crypto) linked to swimming pools or water playgrounds in the United States were reported in 2016, compared with just 16 outbreaks in 2014, according to the CDC’s Morbidity and Mortality Weekly Report (MMWR).

Cryptosporidium, a parasite, can spread when people swallow something that has come into contact with the feces of a sick person, such as pool water contaminated with diarrhea.

There are many species of Cryptosporidium that infect animals, some of which also infect humans. The parasite is protected by an outer shell that allows it to survive outside the body for long periods of time.  

Standard levels of chlorine and other pool germ killers kill most germs within a few minutes. However, due to the outer shell, Cryptosporidium is extremely hard to kill at standard levels of pool germ killers. In fact, it can survive up to 10 days in water that is properly treated with chlorine.

As a result, Crypto, the disease caused by Cryptosporidium, is the most common cause of diarrheal illness and outbreaks linked to swimming pools or water playgrounds.

“To help protect your family and friends from Crypto and other diarrhea-causing germs, do not swim or let your kids swim if sick with diarrhea,” said Michele Hlavsa, R.N., M.P.H., chief of CDC’s Healthy Swimming Program.

The CDC states that water should be treated with high levels of chlorine when responding to a diarrheal incident in the pool.

In 2010, the CDC launched CryptoNet, which is a DNA fingerprinting–based tracking system for illness caused by a parasite. This system helps states detect and control outbreaks by identifying which types of Cryptosporidium organisms are causing infection.