Officials Label Lake Illness as Probable

ST. MARYS — State officials have labeled the illness of a Montgomery County man earlier this year as probably caused by exposure to water in Grand Lake St. Marys.

Ohio Department of Health Spokesperson Tess Pollock told The Evening Leader health officials reviewed the case — which involved a man who was fishing on the lake earlier this year — and determined it as a probable case of an illness linked to the water. The state has four classifications for illnesses — not a case, suspected case, probable case and confirmed case.

"It's the only probable case we do have at this time," Pollock said. "Currently there are two other reports of illness that are related to Grand Lake St. Marys and those are under investigation."

Pollock said state officials are investigating two additional cases of illness at other Ohio lakes — Buckeye Lake and Lake Erie. A probable case meets the criteria of a suspected case — the presence of an algal bloom, onset of associated signs and symptoms within a reasonable time after exposure and without identification of another cause of illness — but includes laboratory documentation of a harmful algal bloom in the water. A confirmed case meets the criteria of a probable case combined with professional judgment based on medical review.

Last year, there were 21 cases investigated by the Ohio Department of Health regarding Grand Lake St. Marys. Twelve of those cases came back as not a case. So far this year, there have been nine reported cases of illness and two have been deemed not a case while two other were lost on follow-up and involved out-of-state people.

"We've had a lot fewer reported illnesses this year than last year," Pollock said. "And I think a lot of that has to do with the education we are doing."

Currently, Grand Lake St. Marys is listed as a public health advisory under the revamped warning system unveiled this year. As part of a public health advisory, visitors to the lake are encouraged to refrain from swimming and wading in the lake, water should not be swallowed and surface scum should be avoided. In the most recent round of testing, conducted last week, microcystin levels in the lake ranged from 11.2 parts per billion to 14.7 ppb. Last year, microcystin levels exceed 2,000 ppb.

Portions of Buckeye Lake — Brooks and Fairfield beaches — and Lake Erie — Maumee Bay State Park Beach — also are under public health advisories. Other parts of Lake Erie, near Kelleys Island State Beach Park, Battery Park and Lions Park Beach, are under algae bloom advisories.

To keep up to date on lake conditions around the state, visit