ANIHWA 2014 - ppel à projets transnational pour la recherche sur la santé et le bien-être animal

Emergence of highly pathogenic CAliciviruses in LEporidae through species jumps involving reservoir host introduction. – ECALEP

Submission summary

The project aims at studying the emergence and re-emergence of pathogenic lagoviruses,
notably by exploring the hypothesis of a species jump involving introduction of a reservoir
host species. RHDV and EBHSV are RNA viruses of the genus Lagovirus (Caliciviridae)
affecting European rabbit (OC) and Brown hare (LE), respectively. They are responsible for
two distinct diseases RHD (Rabbit Hemorrhagic Disease) and EBHS (European Brown Hare
Syndrome) that emerged in the early 1980s. RHD in particular causes high mortalities in
wildlife and domestic rabbits, threatening the European rabbit industry. Its impact was
controlled by vaccination until the emergence in 2010 in France of a genetically distant
variant (RHDV2). This new lagovirus partially escapes immunity and has quickly spread
throughout France and subsequently has reached adjacent countries, resulting in
re-emergence of the disease both in domestic and wild populations. RHDV2 is able to
infect the SardinianCape hare causing an RHDV-like disease. This is the first account of
interspecies transmission of a lagovirus between European leporids.
Two competing hypotheses can be put forward to attempt to explain RHDV and EBHSV
origin and the emergence of RHDV2: the evolution from pre-existing non-pathogenic (NP)
viruses circulating in European leporids, or a species jump from Sylvilagus floridanus (SF).
Indeed, several elements suggest that SF may be a reservoir of these viruses. This leporid
species is exotic for Europe where it has been massively introduced from the end of 1970s
to the late 1980s, which fits with the dates of emergence of the diseases. Preliminary data
demonstrate the feasibility of a species jump since SF has been successfully infected by
EBHSV.
With a particular attention on RHDV, we will explore the possibility that RHDV and EBHSV,
and later RHDV2, emerged following 1) viral evolution among known and unknown NP
viruses infecting OC and LE, 2) species jumps of SF viruses which are pathogenic for
recipient leporid species and/or have recombined with OC and LE NP viruses to give rise to
highly pathogenic strains.
Search for the genetic determinisms of pathogenicity would also contribute to understand
how these lagoviruses acquired virulence, notably by studying the host-pathogen
co-evolution through HBGA ligands polymorphism, by identifying the capsid protein codons
under positive selection and establishing the role in infectivity and/or virulence of the
potential glycosylation sites.

Project coordinator

Madame Ghislaine Le Gall-Reculé (Agence nationale de sécurité sanitaie des aliments de l'environnement et du travail)

The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.

Partner

ONCFS OFFICE NATIONAL DE LA CHASSE ET DE LA FAUNE SAUVAGE
Anses Agence nationale de sécurité sanitaie des aliments de l'environnement et du travail
CIBIO/UP CIBIO/UP
Istituto Zooprofilattico Sperimentale della Lombardia ed Emilia Romagna
SVA SVA
INSERM INSERM
IHAP 1225 UMR INRA-ENVT 1225 IHAP

Help of the ANR 240,544 euros
Beginning and duration of the scientific project: February 2015 - 36 Months

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