Differentiation of foot-and-mouth disease virus-infected from vaccinated pigs by enzyme-linked immunosorbent assay using nonstructural protein 3AB as the antigen and application to an eradication program.
Baculovirus-expressed foot-and-mouth disease virus (FMDV) nonstructural protein 3AB was used as the antigen in an enzyme-linked immunosorbent assay. This assay allowed the differentiation of vaccinated from infected pigs. Serial studies were performed using sera collected from pigs in the field. Positive reactions were found in sera from fattening pigs and sows 16 weeks and 3.5 years postoutbreak, respectively. There was, however, no positive reaction in sows with at least 10 vaccinations. Maternally derived antibodies to the 3AB antigen persisted in piglets up to 13 weeks of age. A high correlation coefficient (r = 0.93) was found between the test results from sow sera and those from their offspring. Therefore, piglet serum was a good substitute for sow serum to monitor the infection status of the dam. The application of this assay to serological surveillance in an FMD eradication program in Taiwan showed that the positive reactors steadily decreased over time in both finishers and sows, indicating that the pig population risk of infection by FMDV has decreased.
Chung
Wen-Bin
WB
Department of Veterinary Medicine, National Pingtung University of Science and Technology, Taiwan. wbchung@mail.npust.edu.tw
Sorensen
Karl Johan
KJ
Liao
Pei-Chih
PC
Yang
Pin-Cheng
PC
Jong
Ming-Hwa
MH
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D000956:Antigens, Viral / Q000276:immunology; D016367:Baculoviridae / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005536:Foot-and-Mouth Disease / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D029544:Foot-and-Mouth Disease Virus / Q000276:immunology*; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D014611:Vaccination / Q000662:veterinary; D017361:Viral Nonstructural Proteins / Q000276:immunology*; D014765:Viral Vaccines / Q000008:administration & dosage / Q000276:immunology*
D000914:Antibodies, Viral; D000956:Antigens, Viral; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines; C089383:nsp3 protein, alphavirus