CDC warns about intestinal parasite on the rise in swimming pools and lakes

SALT LAKE CITY, Utah — If you’ve been swimming a lot this summer, sunburns and awkward tan lines are the least of your worries. The government says a microscopic intestinal parasite causing diarrheal infection may be hiding in the water, making itself at home in your intestine for the next two weeks.

This gastrointestinal illness, Cryptosporidiosis, is on the rise in the U.S., with an average 13% increase every year. The Centers for Disease and Control Prevention reports that “Crypto” has been on the rise, recording 444 outbreaks from 2009 – 2017.

Symptoms of “Crypto”

The illness can last one to two weeks, with symptoms such as watery diarrhea, nausea, vomiting, loss of appetite, and fever. “Crypto” is contracted by swallowing the parasites, usually present in untreated or recreational waters, said Utah Department of Health Epidemiologist Delaney Moore.

“That doesn’t mean for sure that’s where they got it,” Moore said. “It can be kind of hard to tell where people got it because you can [contract it] anytime in the week or two before you get sick. But we do see this spreading around in swimming pools.”

The parasite can be found in lakes and swimming pools alike. Because of its protective outer shell, Moore said “Crypto” is highly tolerant of chlorine – making the swimming pool a popular breeding ground for the parasite.

A summertime sickness

Cases typically rise during the summer, Moore said, because people are more likely to be out swimming, going to lakes or waterskiing. Because of this, researchers aren’t concerned with the spike in numbers but are still warning swimmers to take precautions.

“The best prevention is always through handwashing,” Moore said. “You want to make sure you’re washing with soap and water. Hand sanitizers are not very effective against this illness.”

The Utah Department of Health also recommends not swallowing water and for anyone who has been sick with diarrhea, to avoid swimming for up to two weeks after being cleared.

The intestinal parasite in Utah

“Crypto” cases have been on the rise in Utah, with 84 cases in 2019 alone. This is an increase from 56 cases in 2018 and higher than the five year average of 53.6 cases a year, according to the Utah Department of Health.  Moore speculates that the numbers over the last five years are rising because of advances in medical testing.

“[The increase] could be due to more infections,” Moore said. “We also think that part of it could be due to that we’re just getting better at finding infections.”

The detection of “Crypto” can be difficult, sometimes requiring several stool samples before identifying the parasite.

“We hear about the cases that are reported to us when people go to the doctor and get tested,” Moore said. “The testing they do at the doctors has gotten a lot better in the last five years. So we’re getting a lot better at detecting cases that we may have missed before that.”