Agreement of two ELISAs for Mycobacterium avium subspecies paratuberculosis in cattle in Korea

Lee, Kyung Woo; Jung, Byeong Yeal; Hwang, In Yeong; Lee, Su Hwa; Kim, Ji Yeon; Kim, Young Hoan; Lee, Seong Hyo; Moon, Oun Kyoung; Lee, O Soo

Korean Journal of Veterinary Research 2009;49(2):121-125.

Kyung Woo Lee¹, Byeong Yeal Jung¹, In Yeong Hwang², Su Hwa Lee¹, Ji Yeon Kim¹, Young Hoan Kim³, Seong Hyo Lee⁴, Oun Kyoung Moon¹, O Soo Lee¹

¹Animal Disease Diagnostic Center
²Bacteriology and Parasitology Division, National Veterinary Research and Quarantine Service
³Gyeongbuk Veterinary Service Laboratory
⁴Institute of Livestock and Veterinary Research

Abstract

Paratuberculosis caused by Mycobacterium avium subspecies paratuberculosis (Mpt) is a chronic infectious enteric disease with deleterious impact on the performance in ruminants. In Korea, ELISA has been introduced to detect antibodies to Mpt in individual cattle. However, comparison study with ELISA has not been studied until now. In total, a panel of 899 serum samples obtained from dairy cattle was analyzed with two commercial ELISAs for Mpt to assess the performance. Two ELISAs employed in this study were both licensed worldwide. Two ELISAs applied onto same serum samples showed the moderate agreement (kappa value = 0.60). There was non-significant McNemar test (p = 0.0614) between two ELISA results indicating that each proportion detected by two kits did not differ. In addition, the percent agreement between two ELISA results was turned out to be 96.8% which interpreted excellent reproducibility. It was shown from this study that two ELISAs revealed moderate kappa agreement performance. The implication raised is that when ELISAs as diagnostics are used to detect Mpt in individual cattle, positive reaction by either ELISA should be interpreted as serologically Mpt positive due to presumed low sensitivity of ELISAs and their test agreement being less than 100%.

Key Words: agreement, dairy cattle, ELISA, kappa value, Mycobacterium avium subspecies paratuberculosis