West Nile virus re-emerges in Twin Cities metro

West Nile virus, the mosquito-borne bug that can cause fever and headaches and in some cases can prove deadly, has surfaced in Minnesota for the first time this year.

Mosquitoes collected in Scott County this week tested positive for the virus, the Metropolitan Mosquito Control District reported.

There have been no confirmed cases of Minnesotans coming down with West Nile illness yet this summer, and dead birds tested by the mosquito control district also have turned up negative.

Nevertheless, the time is ripe for the virus and it's not a great surprise that the virus should turn up in the mosquito sample, officials said.

People "should take common-sense precautions to avoid mosquito bites," said district ecologist Kirk Johnson.

Those precautions include the use of mosquito repellent, especially at dusk and dawn.

The rising temperatures expected next week, close on the heels of a nearly record-setting wet season, could lead to more mosquitoes spreading the virus to birds, ­officials said.

The virus is most common in open agriculture areas in western and central Minnesota, but cases are possible anywhere.

The virus first arrived in ­Minnesota about 12 years ago. The most confirmed cases occurred in 2007, when there were 116 victims. Disease incidents fell off for four years before 2012, when 103 cases were confirmed.

About one out of 150 people bitten by an infected mosquito develops central nervous system ailments such as encephalitis, a brain infection, or meningitis. About 10 percent of severely infected people die from the illness, and survivors can have long-term nervous system problems.

Most people bitten by infected mosquitoes, however, develop West Nile fever, the less severe form of disease, or fight off the virus without the flu-like symptoms.

The Mosquito Control District keeps track of reports of infected metro-area birds to try to reduce the risk of the virus, which is highest in mid- to late summer. To report a dead bird, go to http://tinyurl.com/kk6myyc.