A rare tick-borne Bourbon virus infection has been confirmed in New York for the first time, according to Stony Brook Medicine. Experts say the finding matters because there is no vaccine or specific treatment, and further cases may be missed or mistaken for other illnesses if the virus becomes more common.

The virus is transmitted by lone star ticks and has been rarely diagnosed. Researchers warned that it could make diagnosis more complicated during the summer and in future years, when tick exposure may increase.