A Lambton County resident has tested positive for the West Nile virus, the first lab-confirmed human case this year, Lambton Public Health said.
Testing of mosquito pools in Petrolia and Oil Springs had already shown the virus was present.
Ontario has had 24 human cases, which are often confirmed in late summer and early fall, late in the mosquito season.
West Nile virus is spread to humans through the bite of an infected mosquito.
The health unit reminds residents to remain vigilant to prevent mosquito bites and eliminate mosquito-breeding sites on their property. Mosquitoes remain active until frost and below-zero temperatures arrive.
For more, call the West Nile info line at 519-383-3824, ext. 3824, or visit www.lambtonpublichealth.ca