A pandemic strain of calicivirus threatens rabbit industries in the Americas.
Rabbit Hemorrhagic Disease (RHD) is a severe acute viral disease specifically affecting the European rabbit Oryctolagus cuniculus. As the European rabbit is the predominant species of domestic rabbit throughout the world, RHD contributes towards significant losses to rabbit farming industries and endangers wild populations of rabbits in Europe and other predatory animals in Europe that depend upon rabbits as a food source. Rabbit Hemorrhagic Disease virus (RHDV) - a Lagovirus belonging to the family Caliciviridae is the etiological agent of RHD. Typically, RHD presents with sudden death in 70% to 95% of infected animals. There have been four separate incursions of RHDV in the USA, the most recent of which occurred in the state of Indiana in June of 2005. Animal inoculation studies confirmed the pathogenicity of the Indiana 2005 isolate, which caused acute death and pathological changes characterized by acute diffuse severe liver necrosis and pulmonary hemorrhages. Complete viral genome sequences of all USA outbreak isolates were determined and comparative genomics revealed that each outbreak was the result of a separate introduction of virus rather than from a single virus lineage. All of the USA isolates clustered with RHDV genomes from China, and phylogenetic analysis of the major capsid protein (VP60) revealed that they were related to a pandemic antigenic variant strain known as RHDVa. Rapid spread of the RHDVa pandemic suggests a selective advantage for this new subtype. Given its rapid spread, pathogenic nature, and potential to further evolve, possibly broadening its host range to include other genera native to the Americas, RHDVa should be regarded as a threat.
McIntosh
Michael T
MT
Foreign Animal Disease Diagnostic Laboratory, Animal and Plant Health Inspection Services, United States Department of Agriculture, Plum Island Animal Disease Center, P,O, Box 848, Greenport, NY 11944, USA. michael.t.mcintosh@aphis.usda.gov
Behan
Shawn C
SC
Mohamed
Fawzi M
FM
Lu
Zhiqiang
Z
Moran
Karen E
KE
Burrage
Thomas G
TG
Neilan
John G
JG
Ward
Gordon B
GB
Botti
Giuliana
G
Capucci
Lorenzo
L
Metwally
Samia A
SA
D000818:Animals; D000956:Antigens, Viral / Q000235:genetics; D001483:Base Sequence; D017250:Caliciviridae Infections / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D004196:Disease Outbreaks; D016679:Genome, Viral; D006470:Hemorrhage / Q000473:pathology; D017929:Hemorrhagic Disease Virus, Rabbit / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D007196:Indiana / Q000453:epidemiology; D008099:Liver / Q000473:pathology; D008168:Lung / Q000473:pathology; D008969:Molecular Sequence Data; D009336:Necrosis / Q000473:pathology; D010802:Phylogeny; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012376:Rodent Diseases / Q000453:epidemiology* / Q000821:virology; D015678:Viral Structural Proteins / Q000235:genetics; D014774:Virulence
D000956:Antigens, Viral; D015678:Viral Structural Proteins; C081149:viral protein 60, rabbit hemorrhagic disease virus