What pathogens can ticks be infected with? - briefly
Ticks commonly carry bacteria such as Borrelia burgdorferi (Lyme disease), Anaplasma phagocytophilum, and Rickettsia spp.; they also transmit protozoa like Babesia microti and viruses such as Powassan and tick‑borne encephalitis virus.
What pathogens can ticks be infected with? - in detail
Ticks serve as vectors for a wide spectrum of microorganisms, including bacteria, viruses, protozoa, and emerging agents. The most clinically significant bacterial agents are:
- Borrelia burgdorferi and related spirochetes, the cause of Lyme disease.
- Anaplasma phagocytophilum, responsible for human granulocytic anaplasmosis.
- Ehrlichia chaffeensis and Ehrlichia ewingii, which produce human monocytic and granulocytic ehrlichiosis, respectively.
- Rickettsia rickettsii and other spotted‑fever group rickettsiae, leading to Rocky Mountain spotted fever and similar illnesses.
- Coxiella burnetii, the agent of Q fever, occasionally detected in tick populations.
- Francisella tularensis, the pathogen of tularemia, found in certain hard‑tick species.
Viral pathogens transmitted by ticks include:
- Tick‑borne encephalitis virus (TBEV), a flavivirus causing encephalitis in Eurasia.
- Powassan virus, a North American flavivirus linked to severe neuroinvasive disease.
- Crimean‑Congo hemorrhagic fever virus (CCHFV), a nairovirus with high case‑fatality rates.
- Heartland virus and Bourbon virus, emerging phleboviruses associated with febrile illness.
Protozoan agents are represented chiefly by:
- Babesia microti and related Babesia species, causing babesiosis, a malaria‑like hemolytic disease.
- Theileria spp., primarily affecting livestock but occasionally reported in humans.
Additional microorganisms of growing concern are:
- Neoehrlichia mikurensis, an emerging bacterial pathogen linked to vascular and febrile syndromes.
- Rickettsia parkeri and other newly identified rickettsial species, expanding the spectrum of spotted‑fever group infections.
- Borrelia miyamotoi, a relapsing fever spirochete transmitted by the same vectors as Lyme‑disease agents.
These agents are maintained in complex enzootic cycles involving vertebrate hosts, tick developmental stages, and environmental factors. Transmission typically occurs during blood feeding, with pathogen acquisition, replication, and migration within the tick before passage to the next host. Understanding this diversity informs surveillance, diagnostic testing, and preventive strategies for tick‑borne diseases.