As the Labor Day weekend arrives with the last hurrah of swimming pool season, health officials are investigating multiple outbreaks of cryptosporidiosis in Johnson County and the Northland.
More than 50 confirmed and suspected cases have been reported in recent weeks, officials said Friday.
The pools have taken measures to “shock” the water with large doses of chlorine to eliminate the chlorine-resistant Cryptosporidium parvum (Crypto) protozoa that cause the infection, officials said. But they are urging people who have had symptoms — diarrhea, abdominal cramps, fever, nausea or vomiting — to stay out of pools for at least two weeks after their symptoms stop because they may still shed protozoa into the water.
“It’s not about the pools. It’s about people who were sick going back to swim too soon,” said Bill Snook of the Kansas City Health Department.
Kansas City is investigating about 30 confirmed and suspected cases of cryptosporidiosis among city residents north of the river. The number may continue to grow, Snook said.
“As we contact sick people, we’re finding more sick people with gastrointestinal symptoms.”
Most of the cases have been linked to a single pool. A second pool is implicated in one case.
The Platte County Health Department said it is investigating one confirmed and 10 suspected cases of cryptosporidiosis among county residents living outside Kansas City limits. The people went to swimming pools within Kansas City’s jurisdiction.
In Johnson County, an outbreak of cryptosporidiosis first reported by health officials in late August continues to grow.
The Johnson County health department initially traced three confirmed cases of cryptosporidiosis to swimming pools in Overland Park and Shawnee. The total number of confirmed and probable cases grew to 11 in August. Four more cases were added this month, with a second pool in Overland Park and one or more pools in Gardner now implicated.
Overland Park officials said Friday that the city was treating indoor pools at the Matt Ross Community Center after learning that a visitor had symptoms before swimming there. The pools were expected to reopen by late Saturday afternoon.
Crypto protozoa are spread by contact with the stool of infected people or animals, by consumption of contaminated food or water, and by person-to-person or animal-to-animal contact. Alcohol-based hand sanitizers don’t kill Crypto, so they do not help stop its spread.
Health officials said people should avoid swallowing pool water and wash their hands frequently. Babies’ diapers should be changed in restrooms, rather than beside the pool. Children should receive frequent restroom breaks.
Cryptosporidiosis outbreaks generally come in cycles, said Nancy Tausz, disease containment director of the Johnson County health department. The number of cases, so far, is not alarming, she said.
“This is usually the time of year when this happens.”