Olathe ? Environmental officials are strongly recommending that all Johnson County swimming pools be closed for the summer because of a contagious intestinal parasite.

The Kansas City Star reports that Johnson County environmental officials offered pool owners and operators two options to deal with the cryptosporidium parasite.

One is to close the pools and the other is to shock them with chlorine.

Closure was identified as the best option.

The county environmental department said that 11 area pools had been implicated as of Friday in the transmission of cryptosporidium.

The county health department is asking people with diarrhea to stay out of pools and said that it has taken more than 30 reports of cryptosporidium cases in recent weeks.