CORTLAND, Ohio - The Ohio Department of Health has issued a bacterium advisory for beaches at Trumbull County’s Mosquito Creek Reservoir.

According to the health department’s BeachGuard water quality website, high bacteria levels have been detected at Mosquito, which covers more than 7,000 acres, making it one of the largest lakes in Ohio.

On Tuesday, samples of Mosquito Lake water detected E. Coli.

A Bacteria Contamination Advisory is posted when the level of bad bacteria in the water has reached unsafe levels and could make you sick. Children, the elderly, and those in ill health or weakened immune systems are advised not to swim.

The Ohio Department of Health, in cooperation with local health departments, monitors beaches along the Lake Erie shoreline for E. coli bacteria.

Water samples are collected at the beaches and the results are reported to the public. If the sample results are greater than the recreational standard of 235 colony-forming units, an advisory is posted to warn swimmers of the risk of illness associated with water contact.

The advisory remains posted until a follow-up sample result is below the recreational standard.