Rabbit hemorrhagic disease virus type 2 epidemic in a rabbit colony in Japan

Abstract

Twenty-three of 42 European rabbits ( Oryctolagus cuniculus ), belonging to the same rabbit colony, died in March 2020 (55% mortality) in Chiba prefecture, Japan. The disease course was extremely acute without indicators of death or hemorrhage. Necropsy revealed liver swelling, discoloration, cloudiness and fragility, and pulmonary edema. Histologically, severe hepatocellular necrosis (mainly peripheral) and intra-glomerular capillary hyalin thrombi were observed. On molecular-biological examination, reverse transcription polymerase chain reaction analysis of RNA from tissues detected a rabbit hemorrhagic disease virus, confirmed as a RHDV-2 VP60 fragment, which shared 99.42% nucleotide identity with the homologous fragment of RHDV-2 German isolate by nucleotide sequence analysis. This report shows the outbreak of rabbit hemorrhagic disease caused by RHDV-2, an emerging infectious disease, in Japan.

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

“…The North American strains, including our 12 California sequences, are more similar to European than to Australian strains collected from 2016 onwards. In fact, RHDV2 originated in France in 2010 (Le Gall‐Reculé et al., 2011), and in 10 years has spread to five different continents (Ambagala, Ababio, et al., 2021; Fukui et al., 2021; Hu et al., 2021; Rouco et al., 2019). WGS and vp60 sequencing data from different parts of the world have confirmed that the circulating strains derive from European viruses (Mahar et al., 2018; O'Donnell et al., 2021).…”

“…In this line, human intervention is considered a key factor in the rapid, worldwide spread of RHDV2 (Rouco et al, 2019). Reculé et al, 2011), and in 10 years has spread to five different continents (Ambagala, Ababio, et al, 2021;Fukui et al, 2021;Hu et al, 2021;Rouco et al, 2019). WGS and vp60 sequencing data from different parts of the world have confirmed that the circulating strains derive from European viruses (Mahar et al, 2018;O'Donnell et al, 2021).…”

“…Mortality associated with RHDV2 infection varies across different reports; it was initially considered lower than with classic RHDV, but there have been recent descriptions of more virulent RHDV2 strains with similar mortality, incubation period, and disease course as classic RHDV (Capucci et al., 2017; OIE, 2021). This new virus rapidly spread across Europe and the rest of the world and, as of July 2021, it has been detected in several European countries, Australia, Africa, North America, and Asia (Ambagala, Ababio, et al., 2021; Fukui et al., 2021; Hu et al., 2021; Rouco et al., 2019).…”

Genetics of the rabbit haemorrhagic disease virus strains responsible for rabbit haemorrhagic disease outbreaks in Japan between 2000 and 2020

“…Eleven RHD outbreaks were reported between 1998 and 2020 [9–14]. Thus far, genetic characterisation of Japanese strains has been performed using only a partial sequence of the major capsid gene, VP60 [10–13]. In this study, whole-genome sequencing of the Japanese RHDV strains and analysis of viral recombination events, followed by phylogenetic characterisation, were performed to completely understand the genetics of RHDV in Japan.…”

“…Eleven RHD outbreaks were reported between 1998 and 2020 [9][10][11][12][13][14]. Thus far, genetic characterisation of Japanese strains has been performed using only a partial sequence of the major capsid gene, VP60 [10][11][12][13].…”