The Ohio Department of Health has issued a bacteria 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.

Water samples taken from Mosquito Lake on Tuesday detected higher than recommended levels of E. Coli, a bacteria found in the intestines of animals that can cause a sometimes life-threatening infection.

Health officials say the source of the bacteria in the lake is not known.

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 with 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 every two weeks and the results are reported to the public.

Since the sample taken most recently at Mosquito Lake showed bacteria levels above the recreational standard of 235 colony-forming units, more frequent testing will be conducted and an advisory has been posted to warn swimmers of the risk of illness associated with water contact.