State health officials have confirmed the first human case of West Nile virus for 2012.
A St. Louis County man became ill with West Nile encephalitis and meningitis in late May after visiting south-central Minnesota, according to the Minnesota Department of Health. He was hospitalized and is recovering.
Culex tarsalis mosquitoes carry the virus and transmit it to humans when the pests bite. Most people are unaffected, but about 1 in 150 people bitten by a mosquito carrying the virus develop a major nervous-system disease.
Officials are urging people to use mosquito repellents and limit outdoor activities at dusk and dawn to avoid bites.
David Neitzel, a Health Department epidemiologist, said the highest risk for West Nile virus is from mid-summer through early fall.
There were two cases of the virus in humans in 2011 and eight in 2010, according to the Health Department.
Symptoms generally show up within three to 15 days of bites and can include headache, high fever, rashes, stiff neck and muscle weakness.