title: Novel calicivirus identified in rabbits, Michigan, USA.
abstract: We report a disease outbreak in a Michigan rabbitry of a rabbit calicivirus distinct from the foreign animal disease agent, rabbit hemorrhagic disease virus (RHDV). The novel virus has been designated Michigan rabbit calicivirus (MRCV). Caliciviruses of the Lagovirus genus other than RHDV have not been described in US rabbit populations. The case-fatality rate was 32.5% (65/200). Clinical signs included hemorrhage and sudden death, with hepatic necrosis. Analysis of viral RNA sequence from >95% of the viral genome showed an average similarity of 79% with RHDV. Similarity of the predicted MRCV capsid amino acid sequence ranged from 89.8% to 91.3%, much lower than the 98% amino acid similarity between RHDV strains. Experimentally infected rabbits lacked clinical disease, but MRCV was detected in tissues by PCR. We propose that MRCV primarily causes subclinical infection but may induce overt RHD-like disease under certain field conditions.
authors: University of Michigan, Unit for Laboratory Animal Medicine, 1150 W Medical Center Drive, Ann Arbor, MI 48109, USA. ingridbe@med.umich.edu
authors: Ingrid L
authors: IL
authors: Bergin
authors: Annabel G
authors: AG
authors: Wise
authors: Steven R
authors: SR
authors: Bolin
authors: Thomas P
authors: TP
authors: Mullaney
authors: Matti
authors: M
authors: Kiupel
authors: Roger K
authors: RK
authors: Maes
mesh_terms: D000818:Animals; D017250:Caliciviridae Infections / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D004196:Disease Outbreaks; D005260:Female; D017929:Hemorrhagic Disease Virus, Rabbit / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008824:Michigan; D010802:Phylogeny; D011817:Rabbits / Q000821:virology*; D017422:Sequence Analysis, DNA