OKLAHOMA CITY (AP) - The Oklahoma State Department of Health says the number of West Nile virus cases is increasing dramatically in the state.

The department says 31 cases of West Nile have been confirmed in 10 Oklahoma counties so far this year. The health department says that number exceeds the total number of West Nile cases in Oklahoma over the past four years - combined.

Tulsa County has reported the highest number of cases, with nine, while Oklahoma County reported six and Carter County reported five.

The department says more than a quarter of the cases have occurred among Oklahomans in their 70s.

The virus is spread through mosquito bites. The health department says people should wear insect repellant and ensure their yard is free of standing water, which attracts mosquitoes.

We'll have more on this on First News tonight.

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