Application of competitive enzyme-linked immunosorbent assay for the serologic diagnosis of classical swine fever virus infection.
A competitive enzyme-linked immunosorbent assay (C-ELISA), based on a truncated E2 recombinant protein of the Alfort/187 strain of classical swine fever virus (CSFV) and a specific monoclonal antibody M1669, was evaluated using 2,000 sera from clinically healthy pigs in Canada (a CSFV-free country) and sera from experimentally infected pigs. The relative specificity and sensitivity of the C-ELISA were 100% and 86%, respectively, at a cutoff of 25% inhibition using negative and positive pig sera, as defined by the neutralizing peroxidase-linked assay (NPLA). A kappa value of 0.91 was obtained, indicating an excellent level of agreement between the NPLA and the C-ELISA. When sera from 120 infected pigs were used in the test at > or = 21 days postinfection, the sensitivity of the C-ELISA and the kappa value increased to 97% and 0.98, respectively. This C-ELISA will be useful when a large number of samples must be tested, as could occur during a disease outbreak or for surveillance or prevalence studies.
Clavijo
A
A
National Centre for Foreign Animal Disease, Winnipeg, Manitoba, Canada.
Lin
M
M
Riva
J
J
Zhou
E M
EM
D000818:Animals; D006691:Classical Swine Fever / Q000175:diagnosis* / Q000235:genetics; D006692:Classical Swine Fever Virus / Q000235:genetics*; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary*; D005188:False Negative Reactions; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000662:veterinary; D013552:Swine
D017931:DNA Primers