Bourbon virus is a rare but serious tick-borne infection that has quietly expanded its known footprint from a single Kansas county in 2014 to a confirmed case on Long Island, New York, just over a decade later. It has no vaccine, no approved antiviral treatment, and no routine commercial diagnostic test — yet most people have never heard of it until it appears in the news after a case is confirmed near them.
This guide covers everything currently known about Bourbon virus: what it is, how it is classified at the molecular level, exactly how it spreads, the full symptom picture (including how it’s often mistaken for other illnesses), how doctors diagnose and manage it, and the specific steps that actually reduce your risk.
Key Facts at a Glance
- What it is: A rare RNA virus (genus Thogotovirus) first identified in 2014 in Bourbon County, Kansas.
- How it spreads: Believed to be transmitted through the bite of an infected tick, most likely the lone star tick.
- Where it’s been found: Confirmed cases in Kansas, Oklahoma, Missouri, and — as of 2026 — New York.
- Symptoms: Fever, fatigue, headache, body aches, nausea, vomiting, and a rash; can progress to organ failure in severe cases.
- Treatment: No specific antiviral or cure exists; care is supportive (fluids, fever and pain management).
- Prevention: Avoiding tick bites is the only proven protective measure — there is no vaccine.
- Risk level: Cases remain very rare, but the true number is likely undercounted due to misdiagnosis as Lyme disease or other tick-borne illnesses.
Overview: What Is Bourbon Virus?
Bourbon virus is a member of the genus Thogotovirus, within the same broad viral family as influenza (Orthomyxoviridae). It was discovered in 2014 by researchers at the CDC’s laboratory in Fort Collins, Colorado, after a Kansas farmer developed an unexplained febrile illness that tested negative for every known tick-borne disease — anaplasmosis, babesiosis, ehrlichiosis, Q fever, Rocky Mountain spotted fever, and tularemia among them. As the CDC’s official overview of the disease confirms, when his blood sample was run against tests for Heartland virus, another newly discovered tick-borne pathogen, scientists noticed cell damage that didn’t match Heartland virus at all. Genetic sequencing revealed an entirely new virus, which was named after the county where the patient lived.
That first patient died roughly eleven days after his symptoms began. He remains the index case for what researchers now recognize as a small but genuine cluster of illness spreading across the central and, more recently, eastern United States. Since 2014, confirmed infections have also surfaced in Oklahoma, Missouri, and — in a case only confirmed in 2026 — New York’s Suffolk County, suggesting the virus’s true range, and the ticks that carry it, extend well beyond the Midwest.
Virology: How Bourbon Virus Is Classified
Understanding Bourbon virus starts with its family tree. For readers who want a more technical breakdown of its classification and case history, it belongs to:
- Family: Orthomyxoviridae — the same family that includes influenza A, B, and C viruses.
- Genus: Thogotovirus — a much smaller, less-studied genus that, unlike influenza, is spread primarily by ticks rather than respiratory droplets.
- Closest relatives: Dhori virus and Batken virus, both found in the Eastern Hemisphere, from which Bourbon virus has diverged significantly at the genetic level.
Structurally, Bourbon virus particles appear in two shapes under an electron microscope: roughly spherical virions around 100–130 nanometers across, and longer filamentous (thread-like) forms — a pattern typical of the influenza-related viruses in its family. Its genome is a single-stranded, negative-sense RNA molecule broken into at least six separate segments, a segmented structure that (as with influenza) creates the theoretical potential for genetic reassortment if a host is infected with more than one related virus at once.
Only a handful of thogotoviruses have ever been linked to human illness anywhere in the world. Before Bourbon virus, the genus had caused just seven confirmed human cases globally — two in Nigeria from Thogoto virus, and five lab-acquired infections from Dhori virus. The 2014 Kansas case was the first thogotovirus illness ever confirmed in the Western Hemisphere, which is part of why it took specialized next-generation sequencing, rather than standard diagnostic panels, to identify it in the first place.
Transmission: How Do You Get Bourbon Virus?
Bourbon virus is believed to spread primarily through the bite of an infected tick, most likely the lone star tick (Amblyomma americanum) — the same aggressive, easily identifiable species (adult females have a single white spot on their back) responsible for spreading ehrlichiosis and alpha-gal syndrome, a red-meat allergy. A related thogotovirus, Batken virus, has also been isolated from mosquitoes, so researchers haven’t fully ruled out other biting insects as occasional carriers, though ticks remain the primary suspect.
Every confirmed patient to date has reported recent tick exposure — from a blood-filled tick still attached at symptom onset in the original 2014 case, to two separate tick bites in the 2026 New York case. There is currently no evidence that Bourbon virus spreads person-to-person, through casual contact, or through respiratory transmission the way influenza does.
Why the Lone Star Tick’s Range Matters
White-tailed deer are central to the lone star tick’s life cycle and geographic spread. As deer populations have grown and moved into suburban areas, tick populations have followed them into residential yards. Warmer winters and longer warm seasons — a pattern documented across the Northeast and Midwest — have also let these ticks stay active longer each year and push their range farther north, which public health experts believe is a major factor behind the tick’s expansion into new states like New York.
Where Bourbon Virus Has Been Confirmed: A Case Timeline
Confirmed cases remain rare — public health officials describe fewer than one confirmed case per year on average across Kansas, Oklahoma, and Missouri combined, with two of those known infections proving fatal. But as physicians treating the New York patient have pointed out, the actual number of infections is almost certainly higher than the confirmed count, since mild cases can resolve without ever being tested and more severe cases are frequently mistaken for Lyme disease or other tick-borne conditions.
Symptoms of Bourbon Virus
Symptoms typically begin within one to two weeks of a tick bite and can range from mild, flu-like discomfort to severe, life-threatening illness. Reported symptoms across confirmed cases include:
Lab testing in confirmed cases has also shown leukopenia (low white blood cell count) and thrombocytopenia (low platelet count) — a lab pattern that overlaps with ehrlichiosis and Heartland virus disease, which is part of why Bourbon virus is so easily mistaken for those illnesses. In the most severe cases, illness has progressed to shortness of breath, acute respiratory distress syndrome, elevated liver enzymes, and ultimately multiple organ failure.
Why Diagnosis Is Often Delayed
Because Bourbon virus symptoms mimic Lyme disease so closely, patients are frequently started on standard Lyme antibiotics — which have no effect on a virus. In the New York case first reported by IBTimes Singapore, the patient’s condition continued to worsen on antibiotic treatment, developing a rash, fever, night sweats, and severe headaches before Bourbon virus was finally identified through specialized testing five years after the triggering tick bite.
…this may be the very, very tip of the iceberg.”
— Dr. Luis Marcos, physician who treated the first confirmed New York patient
Bourbon Virus vs. Other Tick-Borne Illnesses
One reason Bourbon virus goes undiagnosed is that its early symptoms overlap heavily with far more common tick-borne conditions. Here’s how it compares:
| Condition | Pathogen Type | Primary Vector | Responds to Antibiotics? | Confirmed Test Available? |
|---|---|---|---|---|
| Bourbon virus | RNA virus (Thogotovirus) | Lone star tick (suspected) | No | CDC specialty labs only |
| Lyme disease | Bacteria (Borrelia) | Blacklegged (deer) tick | Yes | Yes, widely available |
| Ehrlichiosis | Bacteria (Ehrlichia) | Lone star tick | Yes | Yes, widely available |
| Rocky Mountain spotted fever | Bacteria (Rickettsia) | Dog tick / wood tick | Yes | Yes, widely available |
| Heartland virus | RNA virus (Phlebovirus) | Lone star tick | No | CDC specialty labs only |
The practical takeaway: if flu-like symptoms following a tick bite don’t improve on antibiotics, it’s worth asking a healthcare provider whether a viral tick-borne illness — including Bourbon virus — should be considered, particularly in regions with confirmed lone star tick populations.
Diagnosis
There is currently no commercially available diagnostic test for Bourbon virus in the United States. Per the CDC’s clinical diagnosis and treatment guidance for healthcare providers, molecular (RT-PCR) and serologic testing can only be performed at CDC’s Arbovirus Diagnostic Laboratory, and specimens must be submitted through a state or local health department rather than ordered directly by a physician or patient. This routing requirement is itself a major reason diagnosis is often delayed — as seen in the New York case, where confirmation took roughly five years from the original tick bite.
Treatment
There is no antiviral medication or vaccine approved for Bourbon virus disease. Clinical management is entirely supportive, focused on:
- IV fluids to prevent or treat dehydration
- Medication to control fever and pain
- Close monitoring of blood counts and organ function in more severe cases
- Hospitalization when symptoms are significant enough to require it
One experimental avenue worth watching: a laboratory study in mice found that favipiravir, an antiviral used against other RNA viruses, reduced Bourbon virus severity when given both before and after infection. That result is promising for future research but has not been tested in, or approved for, human patients.
Prevention: Reducing Your Risk
Because there is no vaccine and no cure, avoiding tick bites is the only proven way to reduce your risk of Bourbon virus. Physicians and public health officials recommend:
- Avoid walking through tall grass, dense brush, and wooded areas when possible; stay in the center of marked trails while hiking.
- Treat clothing, boots, and gear with 0.5% permethrin, which remains protective through several washes.
- Use an EPA-registered insect repellent containing DEET, picaridin, or a similar active ingredient on exposed skin.
- Do a full-body tick check after any time spent outdoors, including areas ticks favor — scalp, ears, underarms, waistband, and behind the knees.
- Remove any attached tick promptly and completely using fine-tipped tweezers, pulling straight upward without twisting.
- Shower within two hours of coming indoors, and consider treating pets and yard borders in areas with known tick activity.
Frequently Asked Questions
What is Bourbon virus?
Bourbon virus is a rare RNA virus in the genus Thogotovirus, first identified in 2014 in Bourbon County, Kansas. It causes a febrile illness believed to be spread by tick bites and, in some cases, has proven fatal.
How do you get Bourbon virus?
Bourbon virus is believed to spread through the bite of an infected tick, most likely the lone star tick. There is no evidence it spreads from person to person.
What are the main symptoms of Bourbon virus?
Common symptoms include fever, fatigue, headache, muscle and joint aches, nausea, vomiting, and a rash. Severe cases can progress to breathing difficulty and organ failure.
Is there a cure or vaccine for Bourbon virus?
No. There is no vaccine to prevent Bourbon virus and no antiviral medication approved to treat it. Care is limited to supportive treatment such as IV fluids and fever management.
How is Bourbon virus diagnosed?
There is no routine commercial test. Diagnosis requires specialized molecular or serologic testing performed at CDC’s Arbovirus Diagnostic Laboratory, with samples submitted through a state or local health department.
Is Bourbon virus contagious from person to person?
No documented evidence supports person-to-person spread. It is considered a tick-borne (and possibly insect-borne) illness only.
Where has Bourbon virus been found in the United States?
Confirmed cases have been reported in Kansas, Oklahoma, and Missouri, and — as of a 2026 case in Suffolk County — New York, suggesting the range of the virus and its tick vector may extend further than previously recognized.
Also Read: Anaplasmosis Tick-Borne Disease: Symptoms & Treatment
