Soaking up the sunshine during the warm summer months is one of the season’s best perks, but spending extra time outdoors can also bring you into contact with a few unwelcome pests. A recent reminder of this came in early August 2026, when the Suffolk County Department of Health issued a public health advisory regarding three suspected cases of tularemia, more famously known as “rabbit fever.” As reported by CNN, this rare but severe bacterial illness is definitely worth having on your radar before you head out on your next trail walk.
At its root, rabbit fever is caused by a virulent bacterium called Francisella tularensis. People usually contract the infection through bites from infected ticks or deer flies, though it can also be picked up by direct contact with infected animal carcasses or by inadvertently inhaling contaminated farm dust. While the United States sees fewer than 200 cases in a typical year, milder winters have allowed tick populations to expand into new territories. Staying proactive with outdoor safety and seeking a prompt diagnosis if you feel unwell will help ensure your time in nature stays both fun and safe.
What is rabbit fever?
Tularemia, also known as rabbit fever, is a relatively uncommon zoonotic bacterial illness caused by Francisella tularensis. The pathogen is naturally present in small mammals, especially wild rabbits, hares and rodents.
The Centers for Disease Control and Prevention (CDC) has compiled data showing the peak transmission period to humans is May through September. The bacteria are transmitted by the bites of the Lone Star tick (Amblyomma americanum), the American dog tick (Dermacentor variabilis), and deer flies.
Healthcare Policy Analyst Anne Kamwila tells Blavity Health, “Humans can also contract rabbit fever through direct contact with infected animal tissue (hunting or skinning), contaminated water or undercooked meat from infected rabbits, or by inhaling aerosolized dust contaminated with the bacteria. Tularemia is not transmitted from person to person.”
What’s happening in your body
Francisella tularensis infects the body by entering through a tick bite, a skin cut, or the mucous membranes, and attacks the front-line defense of the immune system.
Research published by the National Institutes of Health (NIH) indicates that the bacterium is an “intracellular pathogen” that enters white blood cells, particularly macrophages. Rather than being destroyed, F. tularensis evades the digestive compartment of the macrophage and grows rapidly in the cytoplasm of the cell.
The bacteria multiply and spread via the lymphatics to the regional lymph nodes, leading to extensive swelling, tissue necrosis, and painful ulceration at the site of entry. The bacteria may disseminate into the bloodstream, causing generalized inflammation, tissue damage, and systemic toxicity if left untreated.
Causes of rabbit fever
The clinical manifestations of rabbit fever are directly related to the route of entry of F. tularensis into the human host. Symptoms typically occur three to five days after exposure, though they can appear at any time between one and 21 days.
According to the Cleveland Clinic, the most common clinical forms include:
- Ulceroglandular Tularemia: This form is triggered by a bite from a tick or fly and results in an open skin ulcer at the site of the bite with painful, massively swollen lymph glands.
- Glandular Tularemia: Similar to ulceroglandular, but presents with swollen lymph nodes without an obvious skin sore.
- Oculoglandular Tularemia: When bacteria enter the eye, resulting in pain, redness, swelling and ulceration on the inside of the eyelid.
- Oropharyngeal Tularemia: Results from the consumption of poorly cooked infected meat or drinking of contaminated water, characterized by a serious sore throat, mouth ulcers and tonsillitis.
- Pneumonic Tularemia: The most serious form, which occurs when the bacteria are inhaled in dust or as an aerosol, and there is high fever, chest pain, cough and severe breathing difficulty.
Health risks and complications
Rabbit fever can rapidly progress to life-threatening systemic complications if left untreated.
According to the CDC, primary complications include:
- Sepsis and Septic Shock: When bacteria invade the bloodstream, they can trigger an overwhelming inflammatory response throughout the body, leading to a drop in blood pressure and reduced oxygen delivery to vital organs.
- Pneumonia and Lung Failure: Acute respiratory failure, which may require mechanical ventilation, may result from inhalation or secondary spread from the blood.
- Meningitis: In rare cases, the infection can cross the blood-brain barrier (BBB), leading to dangerous inflammation in the membranes surrounding the brain and spinal cord.
Untreated severe cases of tularemia have a mortality rate of up to 60%, but early treatment with specific antibiotics reduces the death rate to less than 2% according to the CDC.
What to do about potential exposure
Rabbits have a bacterial infection, so immediate action after suspected exposure or tick bites is crucial to avoid complications.
Always wear thick protective gloves when hunting, skinning game or handling wild rabbits, and cook all wild meat thoroughly to an internal temperature of 165°F (74°C). Take precautions when entering high-risk tick areas: wear long sleeves, light-colored pants tucked into socks and apply an EPA-registered insect repellent.
If a tick is attached, use fine-tipped tweezers to pick it up as close to the skin’s surface as possible. Grip and pull upward gently and evenly, avoiding twisting or squeezing the tick’s body. Using rubbing alcohol or hydrogen peroxide, clean the bite area thoroughly and keep a close eye on it for 30 days.
When to see a doctor
If you get a sudden high fever, enlarged lymph nodes, body aches or a growing skin sore following a tick bite or handling wild game, you need medical evaluation as soon as possible.
The New York State Department of Health explains that medical staff treat tularemia with prescription antibiotics specifically targeted against the bacteria, including streptomycin, gentamicin, doxycycline or ciprofloxacin.
Early treatment prevents the bacteria from spreading into the blood. If you go to your doctor, make sure you tell them about any recent outdoor activity, tick bites or contact with wild animals so they can guide your blood tests or antibody screenings.
“The infection is absolutely dangerous and potentially life-threatening if not treated with appropriate antibiotics,” said Daniel Ruderfer, MD, chief of the Division of Pediatric Infectious Diseases at Hackensack Meridian K. Hovnanian Children’s Hospital in New Jersey.
What is the deadliest tick-borne disease?
Although rabbit fever can be debilitating, Rocky Mountain Spotted Fever (RMSF) is well known to public health agencies as the most serious tick-borne illness in North America.
RMSF is caused by the bacterium Rickettsia rickettsii and can cause complete failure of blood vessels throughout the body, leading to organ failure, limb loss or death within eight days of the onset of signs and symptoms if targeted antibiotic treatment is not started promptly, according to the CDC.
Bottom line
Rabbit fever, also known as tularemia, is a very serious and rare bacterial illness that can be transmitted by tick or fly bites, direct contact with infected wildlife or by inhaling contaminated dust. It can lead to painful skin ulcers, swollen lymph glands and even life-threatening sepsis if untreated, but has an excellent response to early antibiotic treatment. The best way to avoid being bitten by ticks is to use a repellent designed to repel ticks, wear protective clothing when handling game and get a medical examination as soon as you notice a fever or sore following an outdoor activity.
Frequently Asked Questions
Is rabbit fever the same as Lyme disease?
No, rabbit fever is caused by the bacterium Francisella tularensis. Ticks can spread it, as can flies, or through direct contact with animals, whereas Lyme disease is caused specifically by Borrelia burgdorferi and is transmitted through blacklegged tick bites.
What happens if rabbit fever is left untreated?
If left untreated, rabbit fever can progress into the bloodstream, causing severe complications like sepsis, lung failure or extensive tissue damage, carrying a mortality rate as high as 30% to 60% for severe forms.
Citations
Christensen J. Three cases of rare tick-borne disease ‘rabbit fever’ suspected in New York. CNN. Published August 4, 2026. https://edition.cnn.com/2026/08/03/health/rabbit-fever-tularemia-new-york
CDC. Lone Star Tick Surveillance.; 2024. https://www.cdc.gov/ticks/data-research/facts-stats/lone-star-tick-surveillance.html
Pandey S, Kant S, Khawary M, Tripathi D. Macrophages in Microbial Pathogenesis: Commonalities of Defense Evasion Mechanisms. Infection and Immunity. Published online November 15, 2021. doi:10.1128/iai.00291-21
Cleveland Clinic. Tularemia: Causes, Symptoms, Treatment & Prevention.; 2022. https://my.clevelandclinic.org/health/diseases/17775-tularemia
CDC. About Tularemia.; 2024. https://www.cdc.gov/tularemia/about/index.html
Nelson CA, Meaney-Delman D, Fleck-Derderian S, Winberg J, Mead PS. Tularemia Antimicrobial Treatment and Prophylaxis: CDC Recommendations for Naturally Acquired Infections and Bioterrorism Response — United States, 2025. MMWR Recommendations and Reports. 2025;74(2):1-33. doi:10.15585/mmwr.rr7402a1
New York State Department of Health . Tularemia.; 2026. https://www.health.ny.gov/diseases/communicable/tularemia/fact_sheet.htm
CDC. About Rocky Mountain Spotted Fever.; 2024. https://www.cdc.gov/rocky-mountain-spotted-fever/about/index.html
CDC. Clinical Signs and Symptoms.; 2024. https://www.cdc.gov/rocky-mountain-spotted-fever/hcp/signs-symptoms/index.html