Every summer, the Center for Disease Control and Prevention addresses the nasty state of American swimming holes – and their recent research has traced thousands of infections to lakes, rivers and the ocean.
A team of researchers analyzed 140 outbreaks that plagued nearly 5,000 people between 2000 and 2014 and even killed two swimmers. Public parks and beaches accounted for about two thirds of the outbreaks, according to the CDC's recent morbidity, and Mortality Weekly Report . And most of these outbreaks occurred in the summer months – just when the water is most inviting.
The most common infections that the CDC raised were swallowing, bagged water. Most of them cause diarrhea – noroviruses, bacterial infections such as Shigella and E. coli and parasites such as Cryptosporidium were all reported . People also have itchy rashes thanks to parasites called bird schistosomes, which usually infect birds and a certain type of snail. But the worms can also wobble into human skin and cause a rash before the misguided parasites die. And poisonous algal blooms fell swimmers in a handful of outbreaks.
It's not all diarrhea and rash; two people died of infections with a brain amoeba named Naegleria fowleri . To avoid it, say the authors of the study, use a nose clip to keep your nostrils closed and do not immerse your head underwater while swimming in warm fresh water and hot springs.
It's enough to keep you completely out of the water, especially because it's not just lakes, rivers and oceans that can become a water treatment plant. A CDC report released in May resulted in nearly 500 outbreaks that affected more than 27,200 people in pools, spas and water parks. One third of them were in hotels, motels, inns and lodges. The main culprits included bacteria causing dangerous pneumonia called legionnaires' disease; Pseudomonas, causing a rash and a swimmer's ear; and again the diarrhea parasite, Cryptosporidium .
Most of these infections thrive in dirty water (although Crypto can survive even in chlorinated pools). This is particularly worrisome given that the CDC reported health or safety violations in 80 percent of public water facilities in five different states in 2016. Most were due to inadequate disinfection, and the worst injuries were in children's pools. Gross.
Disinfection, of course, claims to cause another CDC report. He examined strange symptoms in an indoor water park in Ohio, where employees reported difficulty breathing, burning eyes, and vomiting. The CDC finally concluded that chlorine disinfectants reacted with proteins from swimmer's piss, sweat, dead skin and lotions. The chemical reaction combined with a faulty ventilation system and produced a poisonous cloud, which the staff then inhaled.
So, what does a swimmer do? First of all, watch out for signs, this latest CDC report says. If a shield says, do not swim, then not. swim. Even if you have diarrhea or recently had diarrhea, do not put your infectious body in water that you share with other people. Of course, in the open air in lakes, ponds, rivers and in the ocean, even without you can get someone who is actively puking in it into the water. For example, rainwater runoff can flush human and animal feces into the water. Thus, floods, discharges of sewage treatment plants and boats can take place.
A good rule of thumb is that if the water looks rough, do not swim in it – especially if there are already dead things like fish in it, the study says. And even if it looks immaculate, do not swallow it and definitely not snort it. Happy swim!