Incursions of rabbit haemorrhagic disease virus 2 in Canada—Clinical, molecular and epidemiological investigation

Abstract

Rabbit haemorrhagic disease virus 2 (RHDV2) is a newly emerging Lagovirus belonging to the family Caliciviridae. After its first discovery in 2010 in France, this highly pathogenic virus rapidly spread to neighbouring countries and has become the dominant strain, replacing the classical RHDV strains. RHDV2 was first reported in North

Early circulation of rabbit haemorrhagic disease virus type 2 in domestic and wild lagomorphs in southern California, USA (2020–2021)

“…(2021), this points to different, possibly concomitant events of viral incursion in North America in the past 5 years. Nevertheless, a sequence obtained in British Columbia in 2018 (Canada 2018) (Ambagala, Schwantje, et al., 2021) partially clusters with the southwestern USA strains, including our 12 California strains. Interestingly, this strain is more similar to the California strains (98.6%–98.7% nucleotide identity), than to Canada 2016 (92.7%) and New York 2020 (97.3%), which suggests that the southwestern USA outbreak may have originated from a strain that was introduced into British Columbia in 2018.…”

“…The southwestern sequences are dissimilar to strains obtained in the Canada 2016 and New York 2020 outbreaks (Ambagala, Schwantje, et al., 2021; USDA‐APHIS, 2020). As suggested by O'Donnell et al.…”

“…In 2018, a phylogenetically different RHDV2 strain caused high mortality in colonies of feral domestic rabbits on the coast of British Columbia, Canada (USDA‐APHIS, 2018). There were further detections in Vancouver (British Columbia), Canada, in 2019, but the viral sequences differed from those obtained the previous year in the same region (Ambagala, Schwantje, et al., 2021; USDA‐APHIS, 2018, 2020). At the same time, RHDV2 was detected in feral and domestic European rabbits in Washington State and Ohio, USA, in 2018 and 2019 (USDA‐APHIS, 2020; Williams et al., 2021).…”

“…Sequences from the Quebec 2016 episode differed from those detected in British Columbia in 2018 and 2019 (USDA‐APHIS, 2020), and so far, no strain similar to the first known event in Quebec has been detected in North America. In March 2020, the virus killed several domestic rabbits in a clinic of New York City, USA; the detected strains differed from those collected in British Columbia in 2018 and were more similar to the strains detected in the same area of Canada the following year (Ambagala, Schwantje, et al., 2021; USDA‐APHIS, 2020). Since its first detection in New Mexico, USA, on 24 March 2020, an outbreak of RHDV2 spread through wild and domestic leporid populations across the entire southwestern USA, Mexico, and, most recently, some northern states of the USA and southern Canada (Government of Alberta, 2021; USDA‐APHIS, 2020, 2021).…”

“…In North America, there have been several detections of RHDV2 since the first report in 2016 in Quebec, Canada (Ambagala, Schwantje, et al., 2021; Rouco et al., 2019; USDA‐APHIS, 2020). In 2018, a phylogenetically different RHDV2 strain caused high mortality in colonies of feral domestic rabbits on the coast of British Columbia, Canada (USDA‐APHIS, 2018).…”