Last year saw 69 cases across the state, including six in Lake County, according to data from the Illinois Department of Public Health.

CBS News medical contributor Dr. Celine Gounder joins to discuss the rise in West Nile virus cases, with nearly 50 infections reported in at least 15 states about half classified as severe.

Health officials in Lake County, Illinois, have confirmed the county’s first human case of West Nile Virus (WNV) this year. Officials from the Lake County Health Department and Community Health Center say they have identified this year’s first human case of neuroinvasive West Nile Virus in a Lake County resident who