Viruses (Mar 2023)

First Expert Elicitation of Knowledge on Possible Drivers of Observed Increasing Human Cases of Tick-Borne Encephalitis in Europe

  • Claude Saegerman,
  • Marie-France Humblet,
  • Marc Leandri,
  • Gaëlle Gonzalez,
  • Paul Heyman,
  • Hein Sprong,
  • Monique L’Hostis,
  • Sara Moutailler,
  • Sarah I. Bonnet,
  • Nadia Haddad,
  • Nathalie Boulanger,
  • Stephen L. Leib,
  • Thierry Hoch,
  • Etienne Thiry,
  • Laure Bournez,
  • Jana Kerlik,
  • Aurélie Velay,
  • Solveig Jore,
  • Elsa Jourdain,
  • Emmanuelle Gilot-Fromont,
  • Katharina Brugger,
  • Julia Geller,
  • Marie Studahl,
  • Nataša Knap,
  • Tatjana Avšič-Županc,
  • Daniel Růžek,
  • Tizza P. Zomer,
  • René Bødker,
  • Thomas F. H. Berger,
  • Sandra Martin-Latil,
  • Nick De Regge,
  • Alice Raffetin,
  • Sandrine A. Lacour,
  • Matthias Klein,
  • Tinne Lernout,
  • Elsa Quillery,
  • Zdeněk Hubálek,
  • Francisco Ruiz-Fons,
  • Agustín Estrada-Peña,
  • Philippe Fravalo,
  • Pauline Kooh,
  • Florence Etore,
  • Céline M. Gossner,
  • Bethan Purse

DOI
https://doi.org/10.3390/v15030791
Journal volume & issue
Vol. 15, no. 3
p. 791

Abstract

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Tick-borne encephalitis (TBE) is a viral disease endemic in Eurasia. The virus is mainly transmitted to humans via ticks and occasionally via the consumption of unpasteurized milk products. The European Centre for Disease Prevention and Control reported an increase in TBE incidence over the past years in Europe as well as the emergence of the disease in new areas. To better understand this phenomenon, we investigated the drivers of TBE emergence and increase in incidence in humans through an expert knowledge elicitation. We listed 59 possible drivers grouped in eight domains and elicited forty European experts to: (i) allocate a score per driver, (ii) weight this score within each domain, and (iii) weight the different domains and attribute an uncertainty level per domain. An overall weighted score per driver was calculated, and drivers with comparable scores were grouped into three terminal nodes using a regression tree analysis. The drivers with the highest scores were: (i) changes in human behavior/activities; (ii) changes in eating habits or consumer demand; (iii) changes in the landscape; (iv) influence of humidity on the survival and transmission of the pathogen; (v) difficulty to control reservoir(s) and/or vector(s); (vi) influence of temperature on virus survival and transmission; (vii) number of wildlife compartments/groups acting as reservoirs or amplifying hosts; (viii) increase of autochthonous wild mammals; and (ix) number of tick species vectors and their distribution. Our results support researchers in prioritizing studies targeting the most relevant drivers of emergence and increasing TBE incidence.

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