News|Articles|October 14, 2026

West Nile virus is the leading cause of mosquito-borne disease in the contiguous United States, causing an average of about 2,000 reported cases a year, including about 1,200 neuroinvasive cases and roughly 120 deaths.^1,2 Most people infected never feel sick, but in a small share of patients, mostly older adults and people who are immunocompromised, the virus invades the central nervous system and can cause meningitis, encephalitis, or paralysis. There is no antiviral therapy and no human vaccine, so recognizing the disease and preventing mosquito bites remain the main tools clinicians and the public have.^3,4