Deadly Resurgence of West Nile Virus Puzzles U.S. Health Officials

Abstract

The United States is experiencing an unusually high number of human infections from West Nile virus (WNV). The number of reported cases is the highest through the third week of October since 2003, according to officials at the Centers for Disease Control and Prevention (CDC) in Atlanta, Ga. Moreover, the toll likely will rise, possibly exceeding 2002 and 2003, when about 3,000 cases of neuroinvasive disease and more than 260 deaths occurred each year, according to CDC. Of 4,531 cases through mid-October, 2,293 were neuroinvasive and 2,238 were non-neuroinvasive. Thus far, 183 people have died this year from those infections. While 48 states reported WNV in people, birds, or mosquitoes (Alaska and Hawaii report no activity), almost 70% of the human infections were confined to eight states—Texas, California, Mississippi, Louisiana, Oklahoma, South Dakota, Michigan, and Illinois—with one-third of them (1,438 cases, 54 deaths) in Texas.