Disappearance of TBEV Circulation among Rodents in a Natural Focus in Alsace, Eastern France

Autor: Yves Hansmann, Marie Moinet, Jean-Michel Demerson, Jean-Marc Boucher, Laure Bournez, Franck Boué, Elodie Devillers, Sara Moutailler, Céline Richomme, Christophe Caillot, Aurélie Velay, Léo Legras, Gérald Umhang
Přispěvatelé: Laboratoire de la rage et de la faune sauvage de Nancy (LRFSN), Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Biologie moléculaire et immunologie parasitaires et fongiques (BIPAR), École nationale vétérinaire d'Alfort (ENVA)-Laboratoire de santé animale, sites de Maisons-Alfort et de Dozulé, Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Strasbourg (UNISTRA), Virulence bactérienne précoce : fonctions cellulaires et contrôle de l'infection aiguë et subaiguë, Immuno-Rhumatologie Moléculaire, Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Strasbourg (UNISTRA), École nationale vétérinaire - Alfort (ENVA)-Laboratoire de santé animale, sites de Maisons-Alfort et de Dozulé
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Pathogens
Pathogens, MDPI, 2020, 9 (11), pp.930. ⟨10.3390/pathogens9110930⟩
Volume 9
Issue 11
Pathogens, Vol 9, Iss 930, p 930 (2020)
ISSN: 2076-0817
Popis: International audience; Tick-borne encephalitis virus (TBEV) depends mainly on a fragile mode of transmission, the co-feeding between infected nymphs and larvae on rodents, and thus persists under a limited set of biotic and abiotic conditions. If these conditions change, natural TBEV foci might be unstable over time. We conducted a longitudinal study over seven years in a mountain forest in Alsace, Eastern France, located at the western border of known TBEV distribution. The objectives were (i) to monitor the persistence of TBEV circulation between small mammals and ticks and (ii) to discuss the presence of TBEV circulation in relation to the synchronous activity of larvae and nymphs, to the densities of questing nymphs and small mammals, and to potential changes in meteorological conditions and deer densities. Small mammals were trapped five times per year from 2012 to 2018 to collect blood samples and record the presence of feeding ticks, and were then released. Questing nymphs were collected twice a year. Overall, 1344 different small mammals (Myodes glareolus and Apodemus flavicollis) were captured and 2031 serum samples were tested for the presence of antibodies against TBEV using an in-house ELISA. Seropositive rodents (2.1%) were only found from 2012 to 2015, suggesting that the virus disappeared afterwards. In parallel, we observed unusual variations in inter-annual nymph abundance and intra-annual larval activity that could be related to exceptional meteorological conditions. Changes in the densities of questing nymphs and deer associated with the natural stochastic variations in the frequency of contacts between rodents and infected ticks may have contributed to the endemic fadeout of TBEV on the study site. Further studies are needed to assess whether such events occur relatively frequently in the area, which could explain the low human incidence of TBE in Alsace and even in other areas of France.
Databáze: OpenAIRE
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