What can be contracted from ticks? - briefly
Ticks transmit a range of pathogens that cause diseases such as Lyme disease, Rocky Mountain spotted fever, ehrlichiosis, anaplasmosis, babesiosis, and tick‑borne encephalitis. Infection occurs when an attached tick feeds long enough to transfer the organism into the host’s bloodstream.
What can be contracted from ticks? - in detail
Ticks are vectors for a range of infectious agents that cause human disease. The most common illnesses transmitted by these arachnids include:
- Lyme disease – caused by Borrelia burgdorferi and, in the western United States, Borrelia mayonii. Early symptoms are erythema migrans, fever, headache, and fatigue; later stages may involve arthritis, carditis, and neurological deficits.
- Anaplasmosis – caused by Anaplasma phagocytophilum. Presents with fever, chills, muscle aches, and leukopenia; can progress to severe respiratory or renal failure if untreated.
- Ehrlichiosis – primarily Ehrlichia chaffeensis and Ehrlichia ewingii. Features include fever, rash, thrombocytopenia, and elevated liver enzymes; severe cases may lead to hemorrhagic complications.
- Rocky Mountain spotted fever – caused by Rickettsia rickettsii. Characterized by high fever, headache, and a maculopapular rash that spreads from wrists and ankles to the trunk; delayed therapy increases mortality.
- Babesiosis – Babesia microti infection. Produces hemolytic anemia, high fevers, and hemoglobinuria; severe disease occurs in immunocompromised or splenectomized patients.
- Powassan virus disease – a flavivirus that can cause encephalitis or meningitis with rapid progression and high fatality rates.
- Tularemia – caused by Francisella tularensis; transmitted by Dermacentor species. Manifests as ulceroglandular lesions, fever, and lymphadenopathy.
- Southern tick‑associated rash illness (STARI) – associated with Borrelia lonestari; results in a localized rash and mild systemic symptoms.
Additional agents, though less frequent, include Coxiella burnetii (Q fever), Hepatozoon spp. (rare parasitic infection), and Bartonella henselae (cat‑scratch disease variant). Each pathogen has a specific geographic distribution linked to tick species: Ixodes scapularis and Ixodes pacificus dominate in the northeastern and western United States, while Dermacentor variabilis and Dermacentor andersoni are prevalent in the central and mountainous regions.
Diagnosis relies on clinical presentation, exposure history, and laboratory testing such as serology, polymerase chain reaction, or blood smear examination. Prompt antimicrobial therapy—doxycycline being the first‑line agent for most bacterial tick‑borne infections—reduces morbidity and prevents complications. Antiviral treatment options are limited; supportive care remains the mainstay for viral encephalitides. Prevention strategies focus on personal protection (protective clothing, repellents, tick checks) and environmental management (landscape modification, acaricide application).