The county's health and parks departments have received more than 20 reports so far of people experiencing diarrhea, vomiting, and stomach cramps starting about 24 to 48 hours after swimming at Horseshoe Lake.
Although there is no laboratory confirmation of a specific virus or bacteria responsible for the illnesses at this time, health district officials are closing the park as a precautionary measure while they investigate, said Jim Zimny of the Kitsap County Health District.
Anyone who visited Horseshoe Lake County Park between Thursday and Sunday and then become ill with diarrhea, vomiting or stomach cramps is asked to call the Health District at 360-337-5623 to report their illness, the number of people affected, and which days they were at the park.
People may also report their illness symptoms online at http://kitsappublichealth.org/about/health-concern.php.
The county park appears to be the only affected area on Horseshoe Lake at this time.
If the symptoms appear severe or do not improve within 24 hours, people are advised to visit their doctor as soon as possible. In most instances symptoms will improve after one to two days.
Officials will be collecting additional water samples for laboratory testing on Monday, and completing a thorough cleaning of the restrooms at the park.