West Nile virus (WNV), a mosquito-borne illness, first emerged in the Western Hemisphere in 1999 in the New York City area and has since spread across the United States. Most people infected with WNV will have no symptoms. About 1 in 5 people infected will develop a fever with other symptoms. Less than 1 percent of those infected will develop a serious, sometimes fatal, neurologic illness.
Why Is the Study of West Nile Virus a Priority for NIAID?
Most human infections are mild, causing fever, headache, and body aches, often accompanied by a skin rash and swollen lymph glands. If the virus crosses the blood-brain barrier, however, it can cause life-threatening conditions that include inflammation of the brain and spinal cord.
How Is NIAID Addressing This Critical Topic?
NIAID supports research on WNV through its comprehensive emerging infectious disease program. This program supports research on bacterial, viral, and other types of disease-causing microbes.
Latest News Releases
NIH Begins Study of Vaccine to Protect Against Mosquito-Borne Diseases, February 21, 2017