What is transmitted by ticks? - briefly
Ticks transmit a variety of pathogens—bacteria such as Borrelia and Rickettsia, protozoa like Babesia, and viruses including Powassan and tick‑borne encephalitis virus. These agents cause illnesses such as Lyme disease, Rocky Mountain spotted fever, babesiosis, and encephalitis.
What is transmitted by ticks? - in detail
Ticks act as vectors for a wide range of pathogenic microorganisms. Their blood‑feeding behavior enables direct inoculation of agents from salivary glands into the host’s skin.
Bacterial agents
- Borrelia burgdorferi complex – causative agents of Lyme disease.
- Anaplasma phagocytophilum – triggers human granulocytic anaplasmosis.
- Ehrlichia chaffeensis – responsible for human monocytic ehrlichiosis.
- Rickettsia spp. – produce spotted fever group illnesses, including Rocky Mountain spotted fever.
- Coxiella burnetii – occasional transmission of Q fever.
Protozoal agents
- Babesia microti – causes babesiosis, a malaria‑like hemolytic disease.
- Babesia divergens – European counterpart of babesiosis.
- Cytauxzoon felis – fatal feline cytauxzoonosis.
Viral agents
- Tick‑borne encephalitis virus – leads to encephalitis in Europe and Asia.
- Powassan virus – rare but severe neuroinvasive disease in North America.
- Crimean‑Congo hemorrhagic fever virus – severe hemorrhagic fever in Africa, Asia, and Eastern Europe.
- Omsk hemorrhagic fever virus – endemic to Siberia.
Other agents
- Dirofilaria spp. – filarial nematodes transmitted to canids and occasionally humans.
Transmission pathways include:
- Salivary injection during feeding.
- Co‑feeding, where adjacent ticks exchange pathogens without systemic host infection.
- Transstadial passage, allowing pathogens to persist through tick developmental stages.
- Transovarial transmission, delivering agents from adult females to offspring.
Geographic patterns reflect vector species distribution: Ixodes scapularis dominates eastern North America, Ixodes ricinus occupies much of Europe, while Dermacentor and Rhipicephalus species predominate in Asia, Africa, and the Mediterranean. Peak activity aligns with warm months when host seeking intensifies.
Preventive measures consist of:
- Wearing protective clothing and applying repellents containing DEET or permethrin.
- Conducting regular body checks after outdoor exposure.
- Managing vegetation to reduce tick habitat.
- Applying acaricides to pets and domestic environments.
- Utilizing available vaccines (e.g., for tick‑borne encephalitis) where indicated.
Understanding the diversity of tick‑borne pathogens informs diagnosis, treatment, and public‑health strategies.