Evaluation of three commercially available Japanese encephalitis virus IgM enzyme-linked immunosorbent assays.

We evaluated performance of three commercial Japanese encephalitis virus (JEV) IgM antibody capture enzyme-linked immunosorbent assay (MAC ELISA) kits with a panel of serological specimens collected during a surveillance project of acute encephalitis syndrome in India and acute meningitis and encephalitis syndrome in Bangladesh. The serum and cerebral spinal fluid specimens had been referred to the Centers for Disease Control and Prevention (CDC) for confirmatory testing. The CDC results and specimen classifications were considered the reference standard. All three commercial kits had high specificity (95-99.5%), but low sensitivities, ranging from 17-57%, with both serum and cerebrospinal fluid samples. Specific factors contributing to low sensitivity compared with the CDC ELISA could not be determined through further analysis of the limits and dilution end points of IgM detection.

Evaluation of IgM antibody capture enzyme-linked immunosorbent assay kits for detection of IgM against Japanese encephalitis virus in cerebrospinal fluid samples.

Infection with Japanese encephalitis virus (JEV) is a major public health problem in Asia. Detection of JEV-specific IgM in serum and cerebrospinal fluid (CSF) by the IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) is currently the most widely used diagnostic method to detect JEV infection. Because of the possible presence of IgM cross-reactivity with other flaviviruses in serum and the high ratio of inapparent-to-apparent JEV infections, a positive result in serum only suggests a recent infection and not necessarily an encephalitic illness caused by JEV. Consequently, detection of JEV-specific IgM in CSF assumes great diagnostic relevance. We evaluated two commercial JEV MAC-ELISA kits using 60 CSF samples obtained from patients with acute encephalitis syndrome. The Panbio and XCyton kits had sensitivities of 65-80% and 95% and specificities of 90% and 97.5%, respectively. Performance information on these commercial JEV MAC-ELISA kits for CSF should assist in laboratory-based JE surveillance programs.