Tularemia is a rare but potentially serious bacterial infection caused by Francisella tularensis. In the United States it can be spread by tick bites — including from the Lone Star tick, American dog tick, and Rocky Mountain wood tick — as well as by deer flies, contact with infected animals (especially rabbits and rodents), contaminated water, and inhaled dust. It is treatable with antibiotics, and most people recover fully when care starts early. Only a licensed clinician can diagnose it; this page is educational and not medical advice.
Last reviewed: 2026-07-20 · Educational only — not medical advice.
Carried by the Lone Star tick. Spread by: American dog tick, Rocky Mountain wood tick, Lone Star tick.
What is tularemia?
Tularemia is an infection caused by the bacterium Francisella tularensis, which naturally infects rabbits, hares, and rodents. People can be infected through several different routes, so symptoms vary depending on how the bacteria enter the body. Tick and deer fly bites usually cause the ulceroglandular or glandular forms, marked by a skin ulcer and swollen, tender lymph nodes. Because F. tularensis is highly infectious and has multiple transmission routes, tularemia is a nationally notifiable disease that public health agencies track.
Symptoms
Sudden fever, chills, headache, muscle aches, and fatigue
A skin ulcer at the bite or contact site with swollen, painful lymph nodes (ulceroglandular form — most common after a tick or deer fly bite)
Swollen, painful lymph nodes without a visible skin ulcer (glandular form)
Eye redness, irritation, tearing, and light sensitivity with swollen lymph nodes near the ear and neck (oculoglandular form)
Sore throat, mouth or throat ulcers, and swollen neck lymph nodes from contaminated food or water (oropharyngeal form)
Cough, chest tightness, and difficulty breathing (pneumonic form — the most serious)
How soon do symptoms appear?
Symptoms usually begin 3–5 days after exposure, with a reported range of about 1–21 days, according to CDC clinical guidance.
Diagnosis
Diagnosis is made by a licensed clinician based on your symptoms, likely exposures (tick or deer fly bites, handling wild animals, outdoor work), and laboratory tests such as blood cultures or antibody testing. Because Francisella tularensis is highly infectious, it is important to tell the laboratory when tularemia is suspected so samples are handled safely. Tularemia cannot be self-diagnosed.
Treatment
Tularemia is treated with antibiotics, and most people recover fully when treatment begins promptly. CDC lists treatment options including gentamicin, ciprofloxacin, levofloxacin, and doxycycline; the specific drug, dose, and duration depend on the form and severity of illness and are chosen by a clinician (several of these are used off-label for tularemia). Do not attempt to self-treat — see a healthcare provider if you think you may have been exposed.
Prevention
Preventing bites and exposures is the most practical protection: use EPA-registered insect repellent, wear long sleeves and pants, and check for and remove attached ticks promptly. Wear gloves when handling wild animals — especially rabbits and rodents — cook game meat thoroughly, and avoid drinking untreated surface water. Do not mow over sick or dead animals; when possible, check the area for carcasses before mowing.
Where it occurs
Naturally occurring tularemia has been reported in every U.S. state except Hawaii, though it remains uncommon — CDC surveillance recorded a mean of about 205 cases nationally each year during 2011–2022 (roughly 150–315 per year), with counts varying and rising in recent years. Cases concentrate in south-central states such as Arkansas, Missouri, Oklahoma, and Kansas. The tick species that spread it — the American dog tick, Rocky Mountain wood tick, and Lone Star tick — together cover much of the eastern, central, and western United States, while deer fly transmission is more common in western states.
When to seek care: See a healthcare provider promptly if you develop a sudden high fever, a skin ulcer, or painful swollen lymph nodes after a tick or deer fly bite, after handling a wild animal, or after outdoor work in an area with dead animals. Seek urgent care for trouble breathing or chest pain. Always tell your provider about any tick or animal exposure so tularemia can be considered and tested for safely. For emergencies such as trouble breathing or anaphylaxis, call emergency services. Educational information only — not medical advice. See our sources and disclaimer.
Tularemia — frequently asked questions
Does the Lone Star tick spread tularemia?+
Yes. The Lone Star tick (Amblyomma americanum) is one of three U.S. ticks that can transmit tularemia, along with the American dog tick and the Rocky Mountain wood tick. Ticks are not the only route, though — deer flies, contact with infected animals, contaminated water, and inhaled dust can also cause it.
Is tularemia the same as Lyme disease or Rocky Mountain spotted fever?+
No — tularemia is a distinct illness caused by different bacteria. For clarity for our readers: the Lone Star tick does NOT transmit Lyme disease at all, and it is not a primary vector of Rocky Mountain spotted fever. RMSF is spread mainly by the American dog tick, Rocky Mountain wood tick, and brown dog tick.
How soon do symptoms appear after exposure?+
Usually 3–5 days, but the range can be roughly 1–21 days according to CDC. Symptoms often begin suddenly with fever, chills, and swollen lymph nodes.
Is tularemia contagious from person to person?+
No. CDC states that person-to-person transmission of tularemia has not been reported.
Is tularemia dangerous?+
It can be serious, especially the pneumonic (lung) form, but most infections are treated successfully with antibiotics when caught early. Prompt medical care makes a real difference.
Tularemia is a rare but treatable bacterial infection spread by ticks (including the Lone Star tick), deer flies, and infected animals. Learn the symptoms, the usual 3–5 day onset, diagnosis, treatment, and prevention. Educational, not medical advice.
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