(KGTV) - The nation's leading health organization is asking swimmers to be vigilant of potentially hazardous situations at public pools this year.
The Centers for Disease Control and Prevention (CDC) said at least 32 outbreaks of the parasite, known as cryptosporidium, or "crypto," were linked to swimming pool or water playgrounds in the U.S. last year. This compares to 16 outbreaks reported in 2014.
In 2016, the agency investigated outbreaks in Arizona, Ohio, Alabama and other states. Arizona identified 352 people sick with crypto from July 2016 - Oct. 2016, compared to no more than 62 cases for any year between 2011 and 2015.
Crypto can be spread when individuals swallow something that has come into contact with feces of a sick person, such as contaminated pool water.
In fact, crypto is the most common cause of diarrheal illness and outbreaks linked to public swimming pools and water playgrounds, according to the CDC. The agency says chlorine is not effective in killing the parasite, which can live up to 10 days in properly treated water.
"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," Michele Hlavsa, chief of CDC’s Healthy Swimming Program, said. "Protect yourself from getting sick by not swallowing the water in which you swim."
Swallowing a mouthful of contaminated water can cause illness for up to three weeks, with diarrhea, stomach cramps, nausea, and vomiting, which can lead to dehydration.
The CDC recommends closing pools that may be contaminated with crypto and treating them with high levels of chlorine to prevent an outbreak. The best way for swimmers to protect themselves is: