Thirteen New West Nile Virus Cases Reported - KXNet - Bismarck/Minot/Williston/Dickinson

Thirteen new cases of West Nile virus are reported in the past week.

That despite traps like these revealing a lower number of mosquitoes statewide.

The state health department is urging North Dakotan's to take precautions outdoors.

West Nile peaked in 2007 when 369 human cases were reported.

But last year there were only five confirmed cases.

Already this fall, fourteen human cases are confirmed and five people have been

hospitalized.

Experts aren't sure why were seeing an increase.

"Normally mosquitoes need water in order to breed so you would probably think more in the summers where were having flooding activity such as the past couple years but we actually didn't see very many cases in those years. But the Culex tarsalis mosquito doesn't really require a lot of water to breed just a little bit will be sufficient for them and they also tend to like drier conditions," says epidemiologist Alicia Lepp with the North Dakota Department of Health.

Three of the fourteen human cases confirmed are in Burleigh County. There have been confirmed cases in horses in Stark and Grant counties.

The mosquito that transmits West Nile is most active during hours around dawn and dusk.