title: Rabbit haemorrhagic disease: advantages of cELISA in assessing immunity in wild rabbits (Oryctolagus cuniculus).
abstract: Rabbit haemorrhagic disease (RHD) is an acute fatal disease of domestic and wild European rabbits (Oryctolagus cuniculus) caused by RHD virus (RHDV). Accurate assessment of immunity is of great importance for the conservation and control of wild rabbits. We evaluated a competitive ELISA (cELISA) against isotype ELISAs for assessing the protective immunity against the disease by challenging 50 wild-caught rabbits with a lethal dose of RHDV. Death or survival to the challenge was used as a criterion to determine the performance characteristics of the assay for the assessment of immunity in rabbits. At 1:10 dilution, a serum exhibiting ≥ 25% inhibition (1:10(25)) was regarded as the presence of RHDV-specific antibodies. Eleven of 16 (68.8%) rabbits with antibodies at 1:10(25) (<1:40) died of RHD. When the cut-off was moved from 25% to 50% inhibition (1:10(50)) at 1:10 serum dilution, the assay sensitivity, specificity and accuracy for the protective immunity were improved from 84%, 54.2% and 69.4% to 84%, 100% and 91.8%, respectively. We also demonstrated at the epitope amino acid sequence level why the presence of the RHDV-cross reactive benign rabbit calicivirus, which interfered with isotype ELISAs, had little impact on the specificity of the cELISA for the diagnosis of RHDV infection. The presence of RHDV-specific antibody at 1:10(50) by the cELISA is a reliable indicator for the protective immunity. In contrast to isotype ELISAs, the cELISA is a valuable specific tool for monitoring the herd immunity to RHD for the conservation and management of wild rabbits in the field.
authors: AgResearch Grasslands, Hopkirk Research Institute, Private Bag 11008, Palmerston North 4442, New Zealand. tao.zheng@agresearch.co.nz
authors: Tao
authors: T
authors: Zheng
authors: John P
authors: JP
authors: Parkes
mesh_terms: D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D000835:Animals, Wild / Q000276:immunology* / Q000821:virology; D000914:Antibodies, Viral / Q000097:blood; D049628:Body Size; D017250:Caliciviridae Infections / Q000276:immunology / Q000401:mortality / Q000662:veterinary*; D036022:Capsid Proteins / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D005260:Female; D017929:Hemorrhagic Disease Virus, Rabbit / Q000235:genetics / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D011817:Rabbits; D012680:Sensitivity and Specificity; D017386:Sequence Homology, Amino Acid; D012737:Sex Factors
chemical_list: D000914:Antibodies, Viral; D036022:Capsid Proteins