Ohio has seen a nearly fourfold increase in the number of diarrhea-causing infections linked to the cryptosporidium parasite commonly found in pools and water parks and spread when people swallow water contaminated with human feces, according to state and federal health officials.
Last year, Ohio health officials identified 1,940 people sick with cryptosporidiosis, also known as Crypto, which represented a 386 percent increase from the median number of cases (399) reported from 2012 through 2015, according to the U.S. Centers for Disease Control and Prevention.
The CDC also reported 24 Crypto-related outbreaks — or multiple cases in one location — in the state last year, and at least 10 of those outbreaks were associated with aquatic venues, according to the CDC and the Ohio Department of Health.
“We had people who had diarrhea go to the pool and swim in the pool, and (fecal) particles may have been left in pool water or in splash pads,” said Sietske de Fijter, state epidemiologist at the Ohio Department of Health. “When we interviewed them as to where they had gone during their incubation period before they became ill, they mentioned many differnet locations. So it’s hard to tease out where the outbreaks started.”
The number of outbreaks in Ohio made up about a third of the 32 outbreaks reported so far to the CDC for 2016 at swimming pools or water playgrounds across the country.
Last year’s outbreak figure was double the national figure from 2014, prompting the CDC to issue a nationwide warning about contaminated pool water just before the pool season begins on the upcoming Memorial Day weekend.
“To help protect your family and friends from Crypto and other diarrhea-causing germs, do not swim or let your kids swim if sick with diarrhea,” said Michele Hlavsa, chief of CDC’s Healthy Swimming Program. “Protect yourself from getting sick by not swallowing the water in which you swim.”
Swallowing just a mouthful of water contaminated with Crypto can make otherwise healthy people sick for up to three weeks with watery diarrhea, stomach cramps, nausea, or vomiting, and can lead to dehydration.
While Crypto is the most common cause of diarrhea illness and outbreaks linked to swimming pools or water playgrounds each year, it is not clear whether the number of outbreaks has increased or whether better surveillance and laboratory methods are leading to better outbreak detection, Hlavsa said.
“We don’t know what was different about last year,” she said. “What we do know is someone somewhere went swimming with diarrhea had an incident in the water, other people came around, drank that contaminated water and became infected. That’s how these outbreaks happen.”