How many encephalitis‑carrying tick species exist? - briefly
Current research recognizes five tick species that are confirmed vectors of encephalitis‑causing viruses. These are Ixodes ricinus, Ixodes scapularis, Dermacentor andersoni, Haemaphysalis longicornis, and Amblyomma americanum.
How many encephalitis‑carrying tick species exist? - in detail
Scientific surveys recognize a confined group of tick species that transmit viruses capable of causing encephalitis in humans and animals. Only those species for which laboratory infection, field isolation, or reliable epidemiological association has been documented are counted.
- Ixodes ricinus – vector of Tick‑borne encephalitis virus (European subtype) and Louping‑ill virus.
- Ixodes persulcatus – carrier of Tick‑borne encephalitis virus (Siberian and Far‑Eastern subtypes).
- Ixodes ovatus – associated with Tick‑borne encephalitis virus (Japanese subtype).
- Ixodes scapularis – transmitter of Powassan virus lineage I (Deer tick virus).
- Ixodes cookei – vector of Powassan virus lineage II (Mammalian‑associated virus).
- Dermacentor andersoni – implicated in transmission of Colorado tick fever virus, which may produce encephalitic manifestations.
- Dermacentor variabilis – occasional carrier of Powassan virus in the United States.
- Amblyomma americanum – linked to Heartland virus and Bourbon virus, both capable of causing encephalitis‑like illness.
- Haemaphysalis longicornis – reported to harbor Tick‑borne encephalitis virus in laboratory studies.
- Haemaphysalis concinna – identified as a vector for Tick‑borne encephalitis virus in parts of Asia.
These ten species constitute the currently verified set of encephalitis‑transmitting ticks. No additional species have achieved the same level of confirmation, although ongoing research may modify the total as new vector‑virus relationships are discovered.