Development of a competitive ELISA based on the LSDV A33 antigen

Goatpoxvirus (GTPV), sheeppoxvius (SPPV), and the Lumpy skin disease virus (LSDV) is a Capripoxvirus belonging to the family poxviridae. They can cause significant economic losses in countries where this disease are endemic. However, effective and convenient diagnostic tools against sera antibody are not readily available until now. Toward this goal, a polyclonal antibody competitive enzyme-linked immunosorbent assay (c-ELISA) of detecting serogroup-specific antibody is established based on major LSDV antigen A33. Serum samples (n = 605) were collected to optimize the c-ELISA from different areas. The cut-off value for the c-ELISA was estimate using percent inhibition (PI) values. The diagnostic performance of test including sensitivity (sn) and specificity (sp) were obtained by receiver operator characteristic (ROC) analysis. Among these analysis, > 57.61% PI value was accepted as cut-off of the c-ELISA, the diagnostic sn an diagnostic sp were reached to 96.4% and 98.5%, at > 95% confidence interval. These results show that the developed competitive ELISA is sensitive, specific, and reliable, which make it appropriate for serological investigation.