A third human case of West Nile virus has been detected in Arkansas. Also, the state Health Department says that other indicators show the area in the state where the disease is found is expanding. The latest human case was detected in Greene County in far northeast Arkansas. Previously, human cases were detected in Izard and Union counties. The virus has been found most recently in mosquito pools and/or birds in Crittenden, Jefferson and Lawrence counties. Previous surveillance revealed the virus in Arkansas, Benton, Boone, Franklin, Johnson, Independence, Logan, Mississippi, Ouachita, Polk, Sebastian, Van Buren and Washington counties. The virus is transmitted by infected mosquitoes to humans, horses and other animals after feeding on diseased birds.