Westward Ho? — The Spread of West Nile Virus

After its surprising detection in New York City in 1999, West Nile virus became a major clinical and public health concern in North America. Drs. Lyle R. Petersen and Edward B. Hayes write about the dramatic westward spread of West Nile virus. West Nile virus, a mosquito-borne flavivirus, was first isolated from a febrile patient in the West Nile region of Uganda in 1937. For the next 60 years, it remained a little-understood cause of febrile illness and sporadic encephalitis in parts of Africa, Europe, and Asia, garnering scant medical attention. After its surprising detection in New York City in 1999, West Nile virus became a major clinical and public health concern in North America. The next year, the Centers for Disease Control and Prevention collaborated with state and local health departments to establish ArboNet, an electronic surveillance system for tracking West . . .