DENVER — This will be the hottest week of the year in Denver, and pools will be a popular hang out spot.  But the Centers for Disease Control and Prevention has a warning about an increase in the number of cases involving a parasite called Crypto.

Reports show from 2009 to 2017, 7,465 people became sick with Crypto, 287 were hospitalized and 1 died.

Crypto is spread by infected poop, and it is hard to kill.  According to the CDC, it can survive for days in chlorinated pool water, at splash parks or even on surfaces disinfected with bleach.  People sick from Crypto can have diarrhea for up to three weeks.

So it’s important to protect yourself and your family.

“Don’t drink the pool water. Don’t drink the splash pad water.  That’s not a drinking fountain,” said Emily Granath, a doctor with Partners in Pediatrics in Denver.

She said families need to wash their hands, and do what they can to prevent the possible spread.

“Don’t go swimming if you’ve had diarrhea.  Don’t go swimming for actually two weeks because you can still shed Crypto in your stool,” she said.