Detection of porcine epidemic diarrhea virus (PEDV) IgG and IgA in muscle tissue exudate (“meat juice”) specimens

The diagnostic performance of porcine epidemic diarrhea virus (PEDV) IgG and IgA ELISAs was evaluated using paired serum and meat juice samples collected from PEDV-negative (n = 50) and PEDV-inoculated pigs (n = 87). Serum samples were tested by PEDV (IgG, IgA) ELISAs using a procedure performed routinely at the Iowa State University-Veterinary Diagnostic Laboratory (ISU-VDL). Serum samples were tested using PEDV serum IgG and IgA ELISA procedures as routinely performed at the Iowa State University-Veterinary Diagnostic Laboratory (ISU-VDL). Serum samples were diluted 1:50 and conjugate concentrations were 1/20,000 for IgG and 1/3000 for IgA. Meat juice samples were tested using the serum PEDV IgG and IgA ELISAs, with modifications, i.e., meat juice samples were diluted 1:25 and conjugate concentrations were 1/40,000 for IgG and 1/10,000 for IgA. Receiver operator characteristic (ROC) curve analyses were used to estimate diagnostic sensitivities and specificities over a range of sample-to-positive (S/P) cutoffs. Consistent with previous reports, this study showed that the PEDV IgG and IgA meat juice ELISAs provided excellent diagnostic performance and suggest that meat juice recovered from samples collected at slaughter could be used in routine PEDV surveillance.