Origin in Africa
The West Nile virus was first discovered in Uganda’s West Nile region in 1937, not in the U.S. as many assume.
First U.S. Outbreak
The virus made its U.S. debut in 1999, causing an outbreak in New York City, spreading rapidly across the country.
Birds Are the Main Carriers
Although mosquitoes transmit the virus, birds are the primary hosts and reservoirs of the disease.
Severe Symptoms Are Rare
Less than 1% of those infected with West Nile virus develop severe neurological symptoms like encephalitis or meningitis.
Horses Are Vulnerable Too
West Nile virus can also infect horses, and equine vaccines are available to protect them.
Human-to-Human Transmission is Rare
Transmission between humans is extremely rare and usually only occurs through blood transfusions, organ transplants, or from mother to child.
There's No Vaccine for Humans
Currently, no human vaccine is available for West Nile virus, though researchers are working on it.
Origin in Infected Mosquitoes
The virus is primarily spread through the bite of infected mosquitoes, especially the Culex species.
More Than 20,000 U.S. Cases in 20 Years
Over 20,000 cases of severe West Nile virus infections have been reported in the U.S. since its introduction.
Prevention is Key
The best protection is prevention—avoiding mosquito bites through repellents, long sleeves, and eliminating standing water where mosquitoes breed.