Tick-borne encephalitis

Definition

A viral zoonosis of the central nervous system caused by tick-borne encephalitis virus (TBEV, genus Flavivirus, family Flaviviridae), transmitted to humans primarily through the bite of infected Ixodes ticks. The disease presents clinically as meningitis, meningoencephalitis, or encephalitis, with myelitis and spinal paralysis occurring in severe cases; roughly one-third of patients develop persistent neurological sequelae including cognitive impairment. TBEV circulates in enzootic cycles involving small mammals and tick vectors across temperate Eurasia, making it a critical concern in medical and veterinary entomology.

Etymology

Example

In Central European forests, Ixodes ricinus nymphs transmit TBEV to foragers and forestry workers during spring and early summer, with peak infection risk coinciding with questing tick activity.

Synonyms

• TBE
• TBEV infection

Related Terms

• tick-borne encephalitis virus
• Ixodes ricinus
• Ixodes persulcatus
• flavivirus
• Arbovirus
• Zoonosis
• vector-borne disease
• Tick paralysis
• Lyme disease

Usage Notes

Distinguished from other tick-associated neurological conditions such as tick paralysis (a toxin-mediated, non-infectious syndrome) and Lyme neuroborreliosis (caused by the spirochete Borrelia burgdorferi). TBEV has three subtypes—European, Siberian, and Far Eastern—differing in virulence and geographic distribution. The term refers specifically to human disease; in veterinary contexts, related flavivirus infections in livestock may be termed 'louping ill' or similar. Vaccination is available for high-risk populations in endemic regions.