Intra- and interlaboratory reproducibility of an ELISA serological test for Lyme disease

Abstract

OBJECTIVES: Lyme disease has been increasingly diagnosed throughout North America since the late 1970s. The clinical diagnosis and epidemiological monitoring of Lyme disease are aided by serological testing for the etiological agent, Borrelia burgdorferi. Numerous authorities have questioned the reproducibility of these serological tests. This study assessed the intra- and interlaboratory reproducibility of an ELISA used to aid in the diagnosis of Lyme disease. METHODS: Twenty-seven sera from cases and noncases were tested by three laboratories. Two of the laboratories repeated the tests once. These testings were part of the 1991 quality control assessment of provincial laboratories carried out by the Laboratory Centre for Disease Control (LCDC), Ottawa. RESULTS: The mean weighted kappa statistics were 0.87 for interlaboratory comparisons and 0.89 for intralaboratory comparisons. CONCLUSIONS: Overall, the ELISA assessed in this study demonstrated good to excellent intra- and interlaboratory reproducibility in the LCDC 1991 quality control assessment when the data were assessed in the categorical scale using the weighted kappa statistic. Generalization of these findings to clinical laboratory settings must be done with caution.