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A parasite found in swimming pools is causing people to get sick, so here's how to stay safe

With summer underway, you may be tempted to cool off and go swimming in the closest pool you can find. Before hopping in, though, know that the U.S. Centers for Disease Control and Prevention (CDC) recently announced that illnesses caused by a fecal parasite found in swimming pools have been steadily on the rise.

According to the CDC report, outbreaks of an intestinal illness called cryptosporidiosis increased by approximately 13% each year from 2009 to 2017, with 7,465 Americans becoming sick with diarrhea and vomiting, among other issues. The majority of outbreaks, 35%, were linked to exposure from water. Cryptosporidiosis can come from the parasite cryptosporidium (crypto), which is the leading cause of disease outbreaks associated with water in the U.S. Crypto can cause outbreaks easily since there can be millions of crypto germs in feces, and small amounts of feces can be left on things like swimsuits and pool floats due to people either having diarrhea in the pool or not cleaning themselves before getting in.

The CDC notes that crypto is a hard parasite to kill, as it can survive for days in chlorinated water in pools, at water-filled playgrounds, or on surfaces disinfected with chlorine bleach. That's scary stuff, but no, it doesn't mean you can't ever go swimming again. It does mean that before hitting up your local pool (or water park, lake, or stream), you should keep some things in mind to stay safe — especially since crypto is most commonly seen during the summer months.

First, it’s important to understand how the parasite gets transmitted to people. Infection can occur when you swallow the parasite while in water contaminated by fecal matter, and so Dr. Jen Caudle, family physician and associate professor at Rowan University, tells Mic that the primary way to not become infected is to avoid, by any means, swallowing water while swimming.

Additionally, you can help prevent crypto outbreaks by practicing good hygiene. While you unfortunately cannot control what other people do, you can control, says Dr. Caudle. “Do not go swimming if you have diarrhea,” she says. “Also make sure that young children are taken to the bathroom regularly and that their diapers are checked frequently.”

If you're feeling sick after taking a dip and you suspect it could be a parasite, the Mayo Clinic notes that cryptosporidiosis symptoms include nausea, vomiting, stomach cramps, and diarrhea that can last for weeks. While the CDC says that the illness typically does not become severe enough to warrant medical treatment, it can be dangerous for certain people. “People who are in poor health or who have weakened immune systems," explains Dr. Caudle, "are at higher risk for more severe and prolonged illness.”

Still, “although symptoms of crypto can be uncomfortable, the good news is that most people with healthy immune systems will be able to recover without treatment,” says Dr. Caudle, adding that “diarrhea can be managed by drinking plenty of fluids to prevent dehydration."

If you've been diagnosed with the illness, the CDC advises you don't swim for at least two weeks after the diarrhea stops, just in case. Otherwise, though, it's okay to go swimming this summer — as long as you're being safe. “People shouldn’t be afraid of pools, but they should just take the proper precautions," says Dr. Caudle.