Which disease does a tick transmit? - briefly
The main illness transmitted by ticks is Lyme disease, caused by the bacterium Borrelia burgdorferi. Ticks can also vector Rocky Mountain spotted fever, anaplasmosis, and babesiosis.
Which disease does a tick transmit? - in detail
Ticks serve as carriers for a variety of pathogenic microorganisms that cause human illness. The most prevalent conditions transmitted by these arachnids include bacterial, viral, and protozoan infections, each linked to specific tick species and geographic zones.
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Lyme disease – Caused by Borrelia burgdorferi (and related species). Primary vector in North America: Ixodes scapularis (black‑legged tick); in Europe: Ixodes ricinus. Early signs: erythema migrans rash, fever, headache, fatigue. Later stages may involve arthritis, neuropathy, or carditis. Diagnosis relies on two‑tier serology; doxycycline is first‑line therapy for most patients.
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Rocky Mountain spotted fever – Agent: Rickettsia rickettsii. Transmitted mainly by the American dog tick (Dermacentor variabilis) and the Rocky Mountain wood tick (Dermacentor andersoni). Symptoms appear 2–14 days after bite: high fever, severe headache, maculopapular rash that spreads from wrists/ankles to trunk. Prompt treatment with doxycycline reduces mortality.
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Ehrlichiosis – Caused by Ehrlichia chaffeensis (human monocytic ehrlichiosis) and Ehrlichia ewingii. Vector: lone‑star tick (Amblyomma americanum). Clinical picture: fever, leukopenia, thrombocytopenia, elevated liver enzymes. PCR or serology confirms infection; doxycycline is recommended.
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Anaplasmosis – Pathogen: Anaplasma phagocytophilum. Transmitted by the same Ixodes species that spread Lyme disease. Presents with fever, chills, myalgia, and neutropenia. Laboratory confirmation through PCR or serology; doxycycline remains the treatment of choice.
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Babesiosis – Protozoan Babesia microti (U.S.) or Babesia divergens (Europe). Vector: Ixodes scapularis (U.S.) or Ixodes ricinus (Europe). Symptoms range from asymptomatic to hemolytic anemia, fever, and jaundice, especially in immunocompromised hosts. Diagnosis via blood smear or PCR; combination therapy with atovaquone and azithromycin, or clindamycin plus quinine for severe cases.
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Tick‑borne encephalitis (TBE) – Flavivirus transmitted by Ixodes ricinus (Europe) and Ixodes persulcatus (Asia). Incubation 7–14 days; biphasic illness with initial flu‑like phase followed by neurological involvement (meningitis, encephalitis, or myelitis). Serology confirms infection; supportive care is standard, with antiviral agents rarely effective. Vaccination is available in endemic regions.
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Southern tick‑associated rash illness (STARI) – Associated with Rickettsia species; vector: lone‑star tick. Produces a localized rash resembling erythema migrans and mild systemic symptoms. Doxycycline often resolves the condition, though the exact pathogen remains under investigation.
Preventive actions focus on avoiding tick exposure, proper removal, and, where applicable, vaccination. Protective measures include wearing long sleeves and pants, applying EPA‑registered repellents containing DEET or picaridin, inspecting skin and clothing after outdoor activities, and using fine‑toothed tweezers to grasp the tick close to the skin and pull steadily. In regions with high incidence of specific diseases, prophylactic doxycycline may be considered within 72 hours of a confirmed bite.
Understanding the spectrum of tick‑borne illnesses, their vectors, clinical manifestations, and treatment protocols enables timely diagnosis and effective management, reducing the risk of serious complications.