title: Detection and quantification of antibodies to Newcastle disease virus in ostrich and rhea sera using a liquid phase blocking enzyme-linked immunosorbent assay.
abstract: A liquid phase blocking ELISA (LPB-ELISA) was adapted for the detection and quantification of antibodies to Newcastle disease virus. Sera from vaccinated and unvaccinated commercial flocks of ostriches (Struthio camelus) and rheas (Rhea americana) were tested. The purified and nonpurified virus used as the antigen and the capture and detector antibodies were prepared and standardized for this purpose. The hemagglutination-inhibition (HI) test was regarded as the reference method. The cutoff point for the LPB-ELISA was determined by a two-graph receiver operating characteristic analysis. The LPB-ELISA titers regressed significantly (P < 0.0001) on the HI titers with a high correlation coefficient (r = 0.875). The two tests showed good agreement (kappa = 0.82; P < 0.0001), relative sensitivity (90.91%) and specificity (91.18%), and accuracy (91.02%), suggesting that they are interchangeable.
authors.affiliation: Graduate Program in Microbiology, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: R L
authors.initials: RL
authors.lastname: Moro de Sousa
authors.forename: H J
authors.initials: HJ
authors.lastname: Montassier
authors.forename: A A
authors.initials: AA
authors.lastname: Pinto
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods* / Q000706:statistics & numerical data; D006385:Hemagglutination Inhibition Tests; D009521:Newcastle Disease / Q000276:immunology* / Q000517:prevention & control; D009522:Newcastle disease virus / Q000276:immunology*; D020311:Rheiformes / Q000276:immunology; D012680:Sensitivity and Specificity; D020310:Struthioniformes / Q000276:immunology; D014611:Vaccination
chemical_list: D000914:Antibodies, Viral