Maricopa County's cryptosporidium outbreak grew to 32 confirmed cases as of Wednesday afternoon.
Health officials say at least four public swimming pools have been linked to infected people. Officials, who would not confirm the locations, said all the operators are complying with protocols to super-chlorinate water to kill any crypto that may exist. There are no easy tests to independently verify the existence of the parasites in water.
"They don't want people getting sick, so the pools that we've talked to have been cooperating and saying sure will shut down for a day... however long it will take to go through the process," Maricopa County Environmental Services manager Greg Epperson said.
Last week a mother told ABC15 said her teen daughter got sick after visiting Wet 'N' Wild in the north Valley.
Wet 'N' Wild tells ABC15 the they are in compliance with CDC and county health standards. A spokeswoman also says the pools are being super-chlorinated weekly as a precaution, and signs inform customers of healthy swimming practices. Those include showering before entering the water and not swimming after bouts of diarrhea.
Cryptosporidium is transmitted by fecal material. County pool inspectors say an infected person swimming could contaminate a whole pool for up to a week even when the water is properly chlorinated. Other people can get the parasite if they ingest any of the water. After several days, they may experience diarrhea and other symptoms.