An outbreak of cryptosporidium has prompted the Johnson County Health Department to ask people to stay out of swimming pools if they’ve had diarrhea recently.

In the past two weeks, the department has received reports of 35 cases of cryptosporidiosis, Nancy Tausz, the department’s disease containment director, told the Kansas City Star Friday.

Other cases have been reported recently in the area, Tausz said. And schools are seeing children returning to class with diarrhea, a key symptom, she said.

Shortly before Labor Day 2007, six subdivision swimming pools in Johnson County were linked to a significant crypto outbreak. Health officials suspected toddlers with full diapers were the chief culprits. The pools were reopened after being treated with massive amounts of chlorine.