The West Nile virus has been detected in Morrow County for the first time in three years.
Greg Barron is the manager of the North Morrow Vector Control District.
He told the East Oregonian newspaper that two test sites have yielded positive West Nile results -- one south of Irrigon, the other in the city of Boardman.
Barron said 110 test sites were positive for West Nile virus during the 2009 outbreak, most of which were on or near the Umatilla National Wildlife Refuge.
The county had one human case of West Nile in 2009. None have been reported this year.
Morrow County and state health officials say the best way to avoid the disease is to eliminate sources of standing water.