Water, water everywhere — but is it safe to drink? Not if it's in a swimming pool or hot tub, according to the Centers for Disease Control and Prevention (CDC). Spurred by numerous recent news reports about outbreaks of illness caused by the Cryptosporidium parasite, the agency warns that swimming pool and hot tub water can be contaminated with this nasty little bug.

The Crypto parasite is found throughout the world and is responsible for an estimated 748,000 cases of cryptosporidiosis every year. It's the leading cause of waterborne illness in the United States. Like the parasite that causes toxoplasmosis, one thing that makes Crypotosporidium unique is a protective outer shell that allows the parasite to survive for weeks without a host. It also can stand up to chlorine and live for up to 10 days in a treated pool or hot tub. 

Here's what else you should know about the parasite in order to steer clear of it this summer.

How it's spread

In swimming pools or hot tubs,  Cryptosporidium spreads when a child or adult who's recently been sick with diarrhea caused by the parasite takes a dip and infected feces wash into the water. Just a mouthful of pool or hot tub water can make someone sick.  

Related: Splash Parks: Keeping Kids Safe in Iffy Waters

The parasite also is found in soil, food or water that's contaminated with the feces of infected humans or animals. It then can be transmitted through raw food or beverages, or food that was handled by someone with unwashed hands.

The symptoms of cryptosporidiosis

Once ingested,  Cryptosporidium drills a hole in the small intestine, bringing on fever and severe gastrointestinal problems — diarrhea, stomach cramping, vomiting. These symptoms show up from two days to one week after the parasite is swallowed.

After two to three weeks, the body will naturally discard the parasite. During its stay it can leave its host's body weak from lack of nutrients and weight loss. It also can damage the immune system. According to the CDC, people with weak immune systems, small children and pregnant women are especially vulnerable during a bout of cryptosporidiosis, because for them it could turn into a more serious or even fatal condition. 

Cryptosporidiosis is diagnosed with a stool sample, so if you develop symptoms after swimming in recreational waters, see your doctor. 

Related: Beach Lovers: How Dangerous is the "Flesh-eating" Vibrio Vulnificus Bacterium?

Treating a crypto infection

There's no medication or other treatment for speeding Crypto through the body and most people recover fully once it's gone. It's important to stay hydrated while cryptosporidiosis runs its course, though. The dehydration can be severe enough to land you in the hospital, says the CDC. A steady diet of liquids and bland food should help. And if it really gets bad, your doctor may prescribe an antidiarrheal drug.

How to outsmart the Cryptosporidium parasite

Whenever splashing around in a swimming pool or lounging in a hot tub, do your best not to swallow. Teach your children to do the same. 

If you're recovering from a stomach illness, you can help protect others by staying out of the water until you're completely well. Even if you're healthy, shower before you go into a pool or jacuzzi. 

If you're a parent, check your little one's diaper frequently to make sure it's clean. Change his diaper as soon as you see he needs it. Take potty-trained kids on frequent bathroom trips. 

Related: Play It Safe at the Water Park

Muriel Vega is a writer with a passion for budget travel and staying safe while abroad. A Georgia State University graduate, she has over 6 years of editorial experience and has written for The Guardian, The Atlantic, The Billfold, among other outlets. In her free time, you can find her baking pies, playing with her two dogs and cat, or planning her next vacation. She spends way too much time on Twitter, one of her favorite social media channels. Her favorite safety tip: Make sure you have all the necessary shots before you go abroad.