Comparison of a commercial ELISA with an indirect fluorescent antibody test to detect antibodies to Lawsonia intracellularis in experimentally challenged pigs

Objective  The ability of a new commercial ELISA to detect pigs with subclinical proliferative enteropathy (PE) was compared with the traditional indirect fluorescent antibody test (IFAT). Methods  Serum samples were selected from pigs with known Lawsonia intracellularis infection status and clinical signs of PE, but the sample population consisted predominantly of pigs subclinically affected by PE. Results  Significant association and agreement were shown between the ELISA and IFAT assays. ELISA results correlated well with the duration of L. intracellularis shedding as detected by polymerase chain reaction. Conclusion  ELISA can be successfully used to monitor L. intracellularis infection in pigs.