Where are encephalitis-causing ticks found? - briefly
Encephalitis‑transmitting ticks are most common in temperate Europe (central and eastern areas) and in Asian regions including Siberia, Japan, and parts of China. They also occur in the northeastern United States, particularly in wooded and grassy habitats.
Where are encephalitis-causing ticks found? - in detail
Encephalitis‑transmitting ticks belong primarily to the genus Ixodes. The two species most commonly implicated are Ixodes ricinus and Ixodes persulcatus. Their distribution determines the risk zones for tick‑borne encephalitis.
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Ixodes ricinus – widespread across western, central and northern Europe. Presence confirmed in the United Kingdom, France, Germany, the Netherlands, Scandinavia, the Baltic states, and parts of Central Europe such as Austria, Switzerland and Italy. The species thrives in temperate climates with moderate humidity.
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Ixodes persulcatus – dominant in eastern Europe and northern Asia. Recorded in Russia (west of the Urals, Siberia, the Far East), the Baltic countries, Poland, the Czech Republic, and extending into Mongolia, Kazakhstan, China (northeastern provinces), and Japan (Hokkaido). It prefers continental climates with cold winters and warm summers.
Both vectors occupy similar habitats:
- Deciduous and mixed forests with dense underbrush.
- Meadow edges, shrublands, and grasslands adjacent to woodlands.
- Altitudes up to 2,000 m where suitable vegetation exists.
- Areas with high leaf litter and moist soil that support small mammals, the primary blood‑meal hosts.
Seasonal activity peaks from spring to early autumn. Nymphs, the most infectious stage for humans, are most abundant between May and July; adult ticks are active from June through September. In northern latitudes, activity may shift later, extending into August.
Human exposure concentrates in:
- Recreational trails, camping sites, and picnic areas within forested regions.
- Agricultural fields bordering woods, where workers encounter questing ticks.
- Residential zones adjacent to tick‑infested habitats, especially gardens with dense vegetation.
Understanding the geographic and ecological parameters listed above enables targeted preventive measures in areas where encephalitis‑bearing ticks are established.