Wake urges hyper-chlorination of pools to combat parasite

Wake County officials are urging public pools in the county to treat their water with extra high levels of chlorine to combat a gastrointestinal disease caused by micro-parasites.

Cases of cryptosporidiosis – a diarrheal disease caused by a parasite called cryptosporidium – are on the rise in Wake County. The number of cases reported in the county has grown each year, from none in 2011 to 13 last year. Seven months into 2016, there have been 20 cases.

The most common symptom is watery diarrhea, which usually lasts one to two weeks. Other symptoms may include stomach pain, nausea, vomiting and fever. People who have weakened immune systems may develop serious and sometimes fatal illness from the parasite, although no fatalities have been reported in Wake County.

“Most experience the normal diarrhea-type symptoms, achiness, feeling miserable for a few days, and it subsides,” said Dr. Sue Lynn Ledford, director of the county Public Health Division. “If someone is immunocompromised, they’re going to become more ill.”

Cryptosporidium is one of the leading causes of waterborne disease in the United States and is found in streams, rivers, lakes and pools, according to the Centers for Disease Control and Prevention. People can become infected if they swallow water carrying the parasite or get it in their mouths.

Cryptosporidium rests in the intestines of infected humans and animals, spreading through their stool. People can also become infected by touching surfaces like bathroom fixtures or handling infected soil or animals and then touching their mouths with their hands.

But the majority of the 20 cases in Wake have come from water in pools and lakes this summer. Cryptosporidium is resistant to normal levels of chlorine in pools, health officials say, and infected pools must be treated with high levels of chlorine to clear out the parasite.

That’s why the county is advising people to hyper-chlorinate their pools, said Andre Pierce, the county’s environmental health and safety director. County pool technicians are going out to all of Wake’s 1,160 public pools (including neighborhood and community pools) to distribute flyers urging hyper-chlorination.

Pierce noted that many pools, including most city pools, regularly hyper-chlorinate, a process that usually requires the pool to close for a time. He also stressed the need to take other preventative measures, such as keeping infected people out of pools, but that can be difficult. Some people may carry the disease but experience no symptoms, while others can still contaminate water weeks after their symptoms have stopped.

“If people have had crypto and these symptoms, they really need to avoid pools for two weeks,” Ledford said.

Ledford also highlighted regular bathroom breaks for children in pools as a best practice to keep water uncontaminated. The CDC advises every hour everyone out for children.

Individual private pools are at much smaller risk of infection since fewer people come in contact with the water. But Pierce says hyper-chlorination is a good practice for any pool. It not only kills any cryptosporidium but it also cleans the pool of algae and other organic matter.

Outside the pool, the CDC says, the best way to protect against the disease is to practice good hygiene, including washing hands thoroughly with soap and water. The CDC warns that alcohol-based hand sanitizers will not effectively kill cryptosporidium.

This story was originally published July 20, 2016 at 6:31 PM with the headline "Wake urges hyper-chlorination of pools to combat parasite."