Taux de prévalence sérologique du virus de la maladie virale hémorragique (VHD) du lapin de garenne (Oryctolagus cuniculus) et de ses formes apparentées au sein de différentes populations sauvages en France

Abstract

A study carried out on 15 free-living populations of wild rabbits showed that VHD (Viral Haemorrhagic Disease) antibodies were present in all these populations. The nonspecificity of these antibodies does not enable to conclude that VHD was present in all these populations. However, our results suggest that most wild populations are partially protected against VHD either directly by VHD virus, or by VHD-like and non-pathogenic viruses. Moreover, the presence of antibodies on uninhabited islands allows to formulate certain hypotheses about the spread of these viruses.Resume. -Une etude menee au sein de 15 populations sauvages de lapin de garenne a mis en evidence la presence d'anticorps VHD (Viral Haemorrhagic Disease) dans toutes ces populations. Le manque de specificite de ces anticorps ne permet pas de certifier la presence de VHD dans toutes ces populations. Toutefois, ces resultats suggerent que la majorite des populations sauvages sont partiellement protegees centre la VHD, soit directement par le virus de la VHD, soit par des virus apparentes et non pathogenes. En outre, la presence d'anticorps en milieu insulaire inliabite permet d'evoquer certaines hypotheses relatives au mode de transmission de ces virus.

Evolution of microparasites in spatially and genetically structured host populations: The example of RHDV infecting rabbits

“…The virulent one is the most spectacular (due to its high lethality) and is the most often found in the field. The avirulent strain has been rarely isolated (Capucci et al, 1996), but its presence is suspected in many field studies (Chasey et al, 1995;Cooke et al, 2000;Marchandeau and BoucrautBaralon, 1999;Marchandeau et al, 1998;Rodak et al, 1990;Sanson et al, 2000;Trout et al, 1997). This can be explained by a likely sampling bias, since rabbit populations have been mostly sampled after an outbreak of RHD mortality.…”

“…RHDV strains isolated in the field are generally highly lethal (up to 95% mortality 2 days post-infection) and transmissible, but interestingly the impact of the virus has been highly contrasted. Some populations have a high proportion of seropositive rabbits in the absence of recorded mass mortality due to the m a n u s c r i p t 5 disease (Chasey et al, 1995;Cooke et al, 2000;Marchandeau and Boucraut-Baralon, 1999;Marchandeau et al, 1998;Rodak et al, 1990;Sanson et al, 2000;Trout et al, 1997),…”

Rabbit haemorrhagic disease and the biological control of wild rabbits, Oryctolagus cuniculus, in Australia and New Zealand

“…Some 22 of these seropositive rabbits were challenged with virulent RHDV and all survived. Rabbits throughout France also carried antibodies that reacted in RHD ELISAs, even on islands where RHD had never been detected or suspected (Marchandeau et al 1998b). The presence of these antibodies in Britain and France now seems explicable given the isolation of a non-pathogenic RCV from domestic rabbits .…”

Serological evidence for a non-protective RHDV-like virus

“…Antibodies against RHD were detected in sera collected in Europe between 1975 and1987, showing that RHDV-like viruses were already present, but simply had not been detected before the first evidence of the disease [33]. More recent serological data suggest that nonpathogenic strains may usually be present in wild European rabbit populations, because high antibody levels have been detected even where RHD had never been recorded or suspected [22,35]. Such non-pathogenic strains are also suspected to occur in Australia and New Zealand, where RHD was introduced in 1995 and 1997, respectively as a control agent of rabbit populations [14,27,29,32].…”