How many encephalitis ticks are there? - briefly
There are two principal tick species that transmit tick‑borne encephalitis: Ixodes ricinus in Europe and Ixodes persulcatus in Siberia and parts of Asia. Both belong to the Ixodes genus and constitute the main global vectors.
How many encephalitis ticks are there? - in detail
Tick‑borne encephalitis is transmitted by a limited set of arthropod species. Scientific surveys have identified roughly twenty tick taxa that act as competent vectors for the encephalitis‑causing flavivirus. The most frequently cited vectors are:
- Ixodes ricinus – widespread in Central and Western Europe, primary carrier in forested zones.
- Ixodes persulcatus – dominant in Siberia and parts of Eastern Europe, responsible for the majority of cases in those regions.
- Dermacentor reticulatus – found in Central Europe and the Balkans, occasional vector in mixed‑habitat areas.
- Dermacentor marginatus – present in Southern Europe and the Mediterranean basin, implicated in sporadic transmission.
- Haemaphysalis concinna – recorded in Eastern Europe and parts of Asia, confirmed vector in laboratory studies.
- Haemaphysalis longicornis – native to East Asia, expanding range into Oceania, experimental evidence of transmission capability.
Additional species with documented vector competence include Ixodes nipponensis, Ixodes scapularis (North America, low natural infection rates), Ixodes pacificus, Ixodes frontalis, Ixodes trianguliceps, Ixodes redikorzevi, Ixodes arboricola, Ixodes hexagonus, Dermacentor andersoni, Dermacentor variabilis, Rhipicephalus sanguineus (experimental), and several Haemaphysalis spp. that have shown virus isolation in field samples.
Geographic distribution of these vectors determines regional incidence. Europe reports 5,000–10,000 human cases annually, largely attributable to the two Ixodes species. Siberia and the Russian Far East record up to 2,000 cases each year, primarily linked to I. persulcatus. Asian countries where H. longicornis and D. marginatus occur report lower numbers, reflecting limited human‑tick contact and differing ecological conditions.
In summary, the global count of tick species capable of transmitting encephalitis viruses stands at approximately twenty, with three to four species responsible for the majority of human infections in endemic zones.