The Maine Center for Disease Control and Prevention is investigating an outbreak of gastrointestinal illness among campers at Patten Pond Camping Resort in Ellsworth.

The resort found E. coli bacteria in its drinking water system, but it’s still unclear if that was the cause of the outbreak. The Maine CDC put a boil-water order in place on Aug. 17 that will remain in effect until the water tests negative for E. coli. Campers are being given bottled water.

Campers at 32 campsites within the resort have shown gastrointestinal symptoms, according to the Maine CDC, which is contacting everyone who has stayed at the resort since Aug. 8. Anyone who stayed at the resort since that date and is experiencing nausea, fever, loose stools or vomiting should contact their health care provider and notify the Maine CDC at 1-800-821-5821.