DENVER -- The Centers for Disease Control and Prevention (CDC) is reporting outbreaks of cryptosporidium have doubled in the last three years; the Denver metro area, however, has only seen one outbreak in the last five years.
Crypto is usually found in public swimming pools and water playgrounds and it comes from fecal matter.
In 2014, 16 outbreaks caused by the bacteria were reported to the CDC. That number doubled by 2016, according to recently released data by the CDC.
Denver7 checked with Denver County's Department's of Public Health and Environment to see how they're working to keep the bacteria out of pools.
Pool operators are required to maintain a daily log to make sure chlorine levels are up to par. Health inspectors inspect pools at least twice a year.
"We are checking those daily logs to ensure they're being kept every day and the chemicals are in balance," public health investigator Joshua Vidal said.
Crytpo can survive in a chlorinated pool up to 12 days.
"When we get a complaint for referral about crypto, the pool operator is required to raise those chlorine levels where it's going to kill that bacteria," said Vidal. "During that time, the pool is obviously not open to the public."
An average of 124 cases of crypto have been reported each year in the last five years and the Denver metro saw one outbreak linked to a public pool during that time, according to the Colorado Department of Public Health and Environment.
The state's health department considers an outbreak when two or more people get the bacteria from the same source.