LINKEDINCOMMENTMORE

SPRINGFIELD -- Ohio has its ninth confirmed human case of West Nile virus this year.

The latest case was confirmed by the Ohio Department of Health Wednesday in Clark County in central Ohio. Earlier this week a case was confirmed in Shaker Heights.

Health department spokeswoman Tessie Pollock said the virus has been found in mosquito pools tested statewide.

Most people develop no symptoms or mild symptoms. But a small percentage may develop a severe form, with symptoms that include headache, high fever, neck stiffness, coma, tremors, convulsions and paralysis.

Ohio has recorded human cases of the virus each year since 2002. There were 21 cases last year.

Officials in Texas are spraying because of a growing West Nile virus epidemic that has infected more than 200 residents and killed 10 of them in the Dallas area.