Health experts have raised concerns that swimming pools and splash pads may be contributing to the spread of Cyclospora infections, which have caused severe diarrhea and gastrointestinal discomfort in thousands of people across the United States this summer.
According to explanations from the Cleveland Clinic in Ohio, consuming untreated water or accidentally ingesting contaminated water in swimming pools, hot tubs, and lakes can allow the parasite to enter the body orally and cause infection.
The clinic pointed out that the tiny parasite causing severe diarrhea “can survive in chlorinated pool water for a considerable amount of time.”
Dr. Rucha Mehta Shah, a gastroenterologist in Arizona, stated that the disinfection methods effective against E. coli bacteria do not kill this parasite. She warned on Instagram on Tuesday, July 14th, “If your child has been to a splash pad this summer and is now sick, it’s something to keep an eye on. These areas are easily contaminated with feces, especially in places where many young children play.”
Shah recommended that patients actively request fecal testing specifically for Cyclospora from their doctors. She emphasized that a general fecal exam may not detect the infection if not specifically tested for.
Cyclospora infects the small intestine, causing gastrointestinal symptoms that can recur, with patients experiencing discomfort one day, feeling better the next, and then relapsing. The most common symptom is watery diarrhea.
Dr. Cynthia Louis Sears, an expert in foodborne and intestinal infections at Johns Hopkins University School of Medicine, stated that people may get infected by consuming untreated water or raw foods (especially unwashed fruits and vegetables). In an article published on July 14th, she pointed out that these foods are often contaminated by parasites through contact with water contaminated with human feces.
Sears advised the public to avoid drinking from lakes, streams, springs, or other untreated water sources. Additionally, hands should be thoroughly washed with soap and water before handling or preparing fresh produce, and fruits and vegetables should be washed with running water before eating or cooking. Cooking can potentially kill this parasite, she noted.
She mentioned that previous outbreaks have been linked to packaged salads, fresh cilantro, fresh basil, raspberries, green beans, and scallions. Sears stated that even a small amount of the parasite is enough to cause infection.
Dr. Maryrose Laguio-Villa, an infectious disease specialist at Rochester Regional Health, stated that most patients develop symptoms within a week of consuming contaminated food or water, but symptoms can appear at any time between 2 days and 2 weeks after exposure.
The Centers for Disease Control and Prevention (CDC) is investigating multiple Cyclospora infection outbreaks to identify the source of infection. The CDC stated, “The specific food source of the infection has not yet been confirmed. Investigators are collecting more information to clarify this outbreak.”
As of July 13th, a total of 1,645 laboratory-confirmed cases have been reported in 34 states across the US, with 141 individuals requiring hospitalization. The patients range in age from 2 to 95 years old, with women accounting for 56% of the cases. No deaths have been reported so far. States with the highest number of cases include Michigan, Ohio, West Virginia, and Kentucky.
The Aquatic Council, a national certification body for water facilities, recommended that individuals experiencing symptoms avoid using public swimming pools. In a Facebook post on July 12th, the council stated, “While swimming pools are not currently considered the primary source of spread for this outbreak, it is still possible to contract Cyclospora through swimming pools.”
Common disinfectants have limited effectiveness against Cyclospora in swimming pools, with the council noting, “It is almost immune to regular chlorination. The most effective way to prevent the spread of this disease through public swimming pools is to strictly prohibit anyone showing symptoms, especially diarrhea, from using the pool.”