"The numbers are growing significantly," said department spokesman Rob Kenny.

Seneca Lake Park's Sprayground, which has water jets shooting up from a hardtop surface, was closed after tests showed the tank system that feeds the water jets was contaminated with a common waterborne disease called cryptosporidiosis.

The disease is highly contagious and can cause diarrhea, nausea and fever that can last for weeks. It usually goes away without treatment in healthy individuals, according to the Centers for Disease Control and Prevention. Five of the illnesses from the Sprayground have so far been confirmed as cryptosporidiosis.

Recovery Likely

No deaths have been associated with the outbreak, and many of the people connected with the outbreak have already recovered, Kenny said.

The Sprayground averages more than a thousand visitors a day in August. It is in the Finger Lakes region, about 45 miles southwest of Syracuse.

The water is monitored several times a day for proper chlorine levels and tested monthly for bacteria like E. coli, said Wendy Gibson, spokeswoman for the state parks department.

The Health Department at first temporarily shut down the Sprayground on Tuesday after receiving more than 100 reported cases of illness dating to early July. After the public was notified of the outbreak, the number of reported illnesses jumped to 746.