The Centers for Disease Control and Prevention warned this Thursday that “crypto” outbreaks linked to swimming have doubled since 2014. A parasite in chlorinated pool water in swimming pools and water playgrounds, known as Cryptosporidium –or crypto for short, is responsible for outbreaks of the disease since 2014.

In 2014, 16 outbreaks were reported in the United States, and last year 32 outbreaks were identified, which prompted the CDC to take action. The parasite can spread when people swallow something that has come into contact with the feces of a sick person, such as water contaminated with diarrhea.

Crypto Outbreak
The CDC has warned about crypto outbreaks in the United States. Image credit: Public Pool.

Crypto outbreaks linked to swimming doubled in 2016

The CDC warned that the outbreaks are increasing over time, as 20 crypto outbreaks linked to swimming were reported in 2011, 16 in 2012 and 13 in 2013. The agency noted it is not clear whether the number of outbreaks has increased or whether better surveillance and laboratory methods are helping to better outbreak detection.

“Crypto is the most common cause of diarrheal illness and outbreaks linked to swimming pools or water playgrounds because it is not easily killed by chlorine and can survive up to 10 days in properly treated water,” said the CDC in a statement published on its website.

They added that swallowing just a mouthful of water contaminated with Crypto can make people sick for up to three weeks with watery diarrhea, stomach cramps, nausea, vomiting, and dehydration.

Standard levels of chlorine or other pool disinfectants kill most germs in a few minutes, but crypto is extremely hard to kill at standard levels, according to the CDC. They recommend closing pools and treating the water with high levels of chlorine, known as hyperchlorination when diarrheal incidents or crypto outbreaks occur in a swimming pool or water playground.

“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, chief of CDC’s Healthy Swimming Program, according to the statement. “Protect yourself from getting sick by not swallowing the water in which you swim.”

CDC issued recommendations to avoid crypto

The CDC said that if a person has diarrhea by crypto, they should wait until two weeks after the diarrhea has stopped to go to a pool or water playground.

Pool Party
The CDC recommends rinsing off in the shower before getting into the water to remove any germs on the body that may contaminate the water, and to take kids on bathroom breaks often to check their diapers. Image credit: Sand Resorts.

In 2016, Arizona, Alabama, Ohio, and other states investigated and controlled several crypto outbreaks. Such outbreaks highlighted the difficulties that treated recreational water venues have with crypto, and the CDC noted that the number of people who can become infected by a small number of germs is remarkable. Arizona alone identified 352 people sick with crypto between July and October 2016, compared with just 62 cases for any year between 2011 and 2015. Ohio, on the other hand, identified 1,940 people sick with the disease, compared to 571 cases for any one year in 2012-2015.

Source: CDC