iStock/schankzMILWAUKEE (CBS 58) -- The first human case of West Nile virus (WNV) has been reported in northern Milwaukee County, according to the North Shore Health Department (NSHD). West Nile virus is spread to people through the bite of an infected mosquito; it is not transmitted from person to person. The health department says it's important for people to stay vigilant about prevent mosquito bites throughout the fall until mosquitos are no longer active -- which is typically after a hard frost. The North Shore Health Department recommends the following:Avoid Mosquito BitesApply insect repellent containing DEET, picaridin, oil of lemon eucalyptus, or IR3535 to exposed skin and clothing. Consider rescheduling outdoor activities during evening or early morning hours, when mosquitoes that spread WNV are most activeWear loose-fitting long sleeves and long pants to help prevent mosquito bites.