A little over a week ago, the Centers for Disease Control and Prevention (CDC) issued a press release warning that outbreaks of a parasite called Cryptosporidium, or Crypto, have doubled in the United States since 2014, from 16 to 32 cases. The diarrhea-causing parasite can infect people in pools and water parks, spreading when someone swallows — yup — water contaminated with the feces of a sick person.
In fact, most infections from public pools are due to Crypto, Federico Laham, MD, the medical director for Orlando Health Arnold Palmer Hospital Infectious Diseases, told Fox News. That’s because Crypto is more resistant to chlorine than your average bug: Usually, common concentrations of chlorine in public pools are not enough to kill the parasite, Laham explained.
But Crypto is far from the only disease lurking in public swimming pools. Some infections, like E. coli or Hepatitis A, are also transmitted from fecal matter that others then swallow in the pool. Other infections, like swimmer’s ear, occur when bacteria get inside your ear and start overgrowing, causing painful skin swelling, Laham said.
Another fun one? Lice. Laham explained that you can actually get lice from infected public swimming pools, though your chances are reduced if you have your hair up in a ponytail or bun. Otherwise, Laham said, your hair is essentially mopping up the pool to pick up lice.
But there is some good news: You’re not likely to get a sexually transmitted infection (STI) from a pool, Laham said.
How to protect yourself
There are a few easy ways to protect yourself: First, avoid swallowing water. Try to keep your ears dry and your hair up, and don’t go swimming if you have an open wound or diarrhea, Laham said. Make sure the public pool you’re going to is visibly well maintained and operated — you should be able to smell the chlorine, Laham explained. And, when you’re done swimming, shower and rinse off all excess chlorine and chemicals.