A rare and potentially deadly tick-borne illness, the Bourbon virus, has been confirmed in New York for the first time, prompting health experts to warn that more cases may go undiagnosed as tick populations increase in the region.

Michael Larkin, a 67-year-old Long Island resident, contracted the Bourbon virus after being bitten by two lone star ticks while working outdoors in Suffolk County in 2021. He experienced fever, rashes, night sweats, and severe headaches but was initially misdiagnosed with Lyme disease, leading to a five-day hospitalization and prolonged symptoms. Only after extensive testing was the correct diagnosis made in April 2026, according to a study by Dr. Luis Marcos and his team at Stony Brook Medicine, published in the American Journal of Tropical Medicine and Hygiene.

The Bourbon virus, named after Bourbon County, Kansas where it was first identified in 2014, is transmitted by lone star ticks and has no known vaccine or specific treatment. Its symptoms mimic those of other tick-borne illnesses like Lyme disease, making diagnosis difficult. The Centers for Disease Control and Prevention (CDC) reports that only a handful of cases have been confirmed in the United States, mostly in the Midwest and South, with two fatalities recorded since the disease’s discovery.

Lone star ticks, which are recognized by the white dot on their backs, have become more common in the northeast due to expanding deer populations and warmer winters. These ticks are known to transmit several illnesses, including ehrlichiosis and alpha-gal syndrome, a condition that can cause a lifelong meat allergy.

Dr. Marcos emphasized, "There are a lot of lone star ticks in New York and in the Northeast, we have dense populations, and when someone is infected with Bourbon virus, symptoms are similar to other tick-borne infections. For these reasons, the Bourbon virus is likely more prevalent than we think in our region and other cases are likely not being diagnosed." He added the need for "expanded viral surveillance, clinical testing and assay development" to help doctors make accurate diagnoses.

Currently, there is no commercial test available for the Bourbon virus. Suspected cases must be sent to specialized laboratories or state health departments for confirmation. Treatment focuses on relieving symptoms, such as administering IV fluids and medications for pain and fever.

Health officials recommend preventing tick bites by avoiding tall grass and wooded areas, using EPA-registered insect repellents, and checking for ticks after spending time outdoors. As tick seasons get longer and populations grow, experts caution that awareness and prevention are key to managing the spread of this rare virus.

Researchers continue to study the prevalence of Bourbon virus and are calling for better surveillance and diagnostic tools to prevent future misdiagnoses and improve outcomes for patients in high-risk areas.

Greg Kretschmar