What are ticks infectious with? - briefly
Ticks transmit bacteria, viruses and protozoa. Notable agents include Borrelia burgdorferi (Lyme disease), Anaplasma phagocytophilum, Babesia microti and tick‑borne encephalitis virus.
What are ticks infectious with? - in detail
Ticks act as vectors for a wide range of pathogenic microorganisms. Transmission occurs primarily through saliva introduced during blood feeding, but some agents are also spread via regurgitation or contaminated feces. The spectrum of infectious agents includes bacteria, viruses, and protozoa, each associated with specific clinical syndromes.
Bacterial agents
- Borrelia burgdorferi – causes Lyme disease; most common in the United States and Europe, transmitted by Ixodes species.
- Anaplasma phagocytophilum – responsible for human granulocytic anaplasmosis; transmitted by Ixodes ticks.
- Ehrlichia chaffeensis – leads to ehrlichiosis; vector is the lone star tick (Amblyomma americanum).
- Rickettsia rickettsii – the agent of Rocky Mountain spotted fever; spread by American dog tick (Dermacentor variabilis) and Rocky Mountain wood tick (Dermacentor andersoni).
- Rickettsia parkeri – causes a milder spotted fever; transmitted by Gulf Coast tick (Amblyomma maculatum).
Protozoal agents
- Babesia microti – produces babesiosis; transmitted by Ixodes scapularis in the Northeastern United States.
- Babesia divergens – causes babesiosis in Europe; vector is Ixodes ricinus.
Viral agents
- Powassan virus – neuroinvasive encephalitis; transmitted by several Ixodes species.
- Tick‑borne encephalitis virus (TBEV) – leads to meningitis and encephalitis in Europe and Asia; vector is Ixodes ricinus and related species.
- Crimean‑Congo hemorrhagic fever virus – severe hemorrhagic disease; transmitted by Hyalomma ticks in Africa, Asia, and Eastern Europe.
Other notable agents
- Francisella tularensis – tularemia; vectors include Dermacentor and Amblyomma ticks.
- Coxiella burnetii – Q fever; occasionally transmitted by ticks, though aerosol spread is more common.
Geographic distribution aligns with the habitats of the respective tick species. Seasonal activity peaks in spring and summer, when nymphal and adult stages seek hosts. Human exposure increases during outdoor activities in wooded or grassy areas, especially when protective clothing and repellents are not used.
Effective prevention relies on personal protective measures, prompt removal of attached ticks, and surveillance of tick populations to identify emerging pathogens. Early diagnosis and appropriate antimicrobial or antiviral therapy reduce morbidity associated with tick‑borne infections.