Today we are introducing you in brief to Tick-bourne encephalitis virus, another flavivirus spread by ticks!

Taxonomy

Tick-bourne encephalitis virus (TBEV) is a positive sense single stranded RNA virus, belonging to the flavivirus family. See other flavivirus Dengue here.

Etymology

The name self-explanatory, a virus which is carried by ticks and causes encephalitis! The first recorded case dates back to the 18th century Scandinavian church records (Lindquist & Vapalahti, 2008).

Hosts

  • Ixodes spp. a species of tick, transmits the virus to humans, though the cycle includes birds and deer.
  • Nymphs have reduced host specificity – so are the most important for human transmission!

Cell Tropism

  • The brain.
  • Dendritic cells found in the skin.
  • Neutrophils – a type of immune cell.

Vector

  • Ixodes spp. are responsible for transmission of TBEV to humans.
  • Habitats range from western Europe to the eastern coast of Japan (Lindquist & Vapalahti, 2008).

Did you know?

Recent studies indicate that the thread of TBEV in europe will escalate with climate change as climate change forces the viruses host northwards. (Nah et al, 2020).

References

  • Kuno G, Chang GJ, Tsuchiya KR, Karabatsos N, Cropp CB. Phylogeny of the genus Flavivirus. J Virol. 1998 Jan;72(1) 73-83. doi:10.1128/jvi.72.1.73-83.1998. PMID: 9420202; PMCID: PMC109351.
  • Labuda, M., Austyn, J. M., Zuffova, E., Kozuch, O., Fuchsberger, N., Lysy, J., & Nuttall, P. A. (1996). Importance of localized skin infection in tick-borne encephalitis virus transmission. Virology, 219(2), 357–366. https://doi.org/10.1006/viro.1996.0261
  • Lindquist, L., & Vapalahti, O. (2008). Tick-borne encephalitis. The Lancet, 371(9627), 1861–1871. https://doi.org/10.1016/S0140-6736(08)60800-4
  • Nah, K., Bede-Fazekas, Á., Trájer, A.J. et al. The potential impact of climate change on the transmission risk of tick-borne encephalitis in Hungary. BMC Infect Dis 20, 34 (2020). https://doi.org/10.1186/s12879-019-4734-4