Swimming and boating at Blue Lake Regional Park will remain closed July 18-20 as public health officials continue to look for what caused diarrhea and vomiting among visitors last weekend.
Deputy Health Officer Dr. Jennifer Vines said the Multnomah County Health Department’s investigation into the illnesses in visitors to the park July 11-13 is ongoing. Based on the onset and symptoms, norovirus is highly suspected.
On Friday, health officials said a study of park visitors, including those who were well and ill, has pinpointed the areas of concern. Those are the Blue Lake swimming beach and lake water, which have been closed to the public since Monday.
The analysis also shows that the park’s playground, bathrooms, drinking water, food concessions and splash pad are considered safe for people to visit, Dr. Vines said. In addition, after a high E. coli level in a July 16 water sample, no E. coli was detected in follow-up tests. E. coli and toxic algae have been ruled out as the cause of any illness.
Dr. Vines said the Blue Lake outbreak was a reminder that anyone with diarrhea, vomiting or stomach upset should avoid recreational swimming until they are well.