title: Comparison of ELISA and HI for detection of antibodies against Wesselsbron disease virus.
abstract: A two-graph Receiver Operating Characteristic analysis was done to determine the optimal cut-off value of an indirect enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Wesselsbron disease (WSL) virus. When ELISA and haemagglutination-inhibition (HI) results of WSL-positive and WSL-negative control sheep sera were compared, the sensitivity of ELISA was 97.9% and that of HI, 87.5%, while the specificity of ELISA and HI were 95.7% and 100%, respectively. The ELISA's superior sensitivity was confirmed by the results of the two assays performed on a simulated range of low-positive sera, which showed that the ELISA was able to detect WSL-antibody levels at least ten times lower than those the HI could. The ELISA was also less cross-reactive than the HI to guinea-pig antisera against nine flaviviruses relevant to southern Africa. The combination of the ELISA's ability to test untreated sera in single dilution and its superior sensitivity and lower cross-reactivity as compared to that of the traditional HI, makes it the assay of choice for automation and large-scale screening of animals for antibodies to WSL virus.
authors.affiliation: Virology Section, Onderstepoort Veterinary Institute, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Williams
authors.forename: M
authors.initials: M
authors.lastname: Schoeman
authors.forename: A
authors.initials: A
authors.lastname: Van Wyk
authors.forename: K
authors.initials: K
authors.lastname: Roos
authors.forename: E J
authors.initials: EJ
authors.lastname: Josemans
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary*; D005416:Flavivirus / Q000145:classification / Q000302:isolation & purification*; D018177:Flavivirus Infections / Q000175:diagnosis / Q000662:veterinary; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary*; D009500:Neutralization Tests / Q000662:veterinary; D012372:ROC Curve; D012680:Sensitivity and Specificity
chemical_list: D000914:Antibodies, Viral