Arboviral Infections
Arboviral (short for arthropod-borne viral) infections are caused by certain viruses which are transmitted by blood-feeding arthropods, primarily mosquitoes, and less often ticks. These infections generally occur during warm-weather months when mosquitoes are active. Insect repellents should be used when outdoors in mosquito-infested areas. In addition, several prevention measures can be implemented to reduce the number of mosquitoes in and around your home, such as placing screens on doors and windows and emptying standing water.
Arboviral Infections in New York City
West Nile virus is the only arbovirus found in NYC mosquitoes that is spread to humans.
Jamestown Canyon virus (JCV) has been found in New York City mosquitoes for the first time in 2025. However, there have been no human cases.
Illness from Jamestown Canyon virus is rarely reported in the United States, with most cases occurring in the upper Midwest. A very small number of cases have been reported from Northeast states, including upstate New York and New Jersey. Many people infected with Jamestown Canyon virus do not have symptoms. For people who do become ill, symptoms usually develop from a few days to 2 weeks after being bitten by an infected mosquito. Symptoms can include fever, headache, and fatigue. Jamestown Canyon virus can also cause severe disease, including meningitis or encephalitis.
While other arboviruses, like eastern equine encephalitis, California serogroup viruses, and St. Louis encephalitis virus are found in the Northeastern US, the types of mosquitoes that carry these viruses are rarely found in New York City.
The primary tick-borne arbovirus in the northeastern US is Powassan virus. This virus has been reported in New York State, but not New York City.
New York City residents who travel outside of the US can also be at risk for other arboviral infections, such as dengue, chikungunya, yellow fever or tick-borne encephalitis viruses that are endemic in other countries. Reported cases of travel-related dengue have been increasing among New York City residents in recent years.
For more information on the number of NYC residents reported to have an arboviral infection other than West Nile, dengue or yellow fever, visit EpiQuery. Please note that very few arboviruses other than West Nile virus and dengue are reported in NYC.
Preventing Mosquito Bites
To protect yourself from mosquito-borne diseases, use an EPA-approved insect repellent. Find additional tips here including steps to reduce mosquitoes around your home.
Additional Resources
- CDC: Arboviral Encephalitides
- CDC: Jamestown Canyon Virus Information
- CDC: Jamestown Canyon Virus Data and Maps