Global West Nile Virus Case Numbers
West Nile virus affects thousands of people worldwide each year. The World Health Organization estimates that tens of thousands of cases occur annually, with many mild infections going unreported. Severe neuroinvasive disease, including meningitis and encephalitis, represents a smaller share of total infections.
Who Is Most Affected by West Nile Virus
Older adults and people with weakened immune systems face the highest risk of severe illness. While anyone can be infected, serious outcomes are more common in individuals over 60. Most infected people show no symptoms or only mild fever and body aches.
Where West Nile Virus Occurs Most
West Nile virus is found in Africa, Europe, the Middle East, North America, and West Asia. In the United States, thousands of human cases are reported each year, with seasonal outbreaks typically peaking in summer and early fall. The Centers for Disease Control and Prevention tracks cases and provides updated data on its website.
