An appraisal of some recent diagnostic assays for Japanese encephalitis.
A study was undertaken in South Arcot district of Tamil Nadu, India to assess relative merits of selected diagnostic techniques for Japanese encephalitis. During the transmission seasons of 1993-1995, a total of 85 patients (mostly pediatric) clinically diagnosed as acute encephalitis or other related central nervous system (CNS) disorders were examined; in 53 (62.4%) a laboratory diagnosis of JE was established. In terms of diagnostic value, immunoglobulin M (IgM) antibody capture ELISA (MAC ELISA) on convalescent serum had the highest sensitivity (89%) and negative predictive value (NPV) (50%). This was followed by MAC ELISA on acute serum and CSF which had similar sensitivity (84%) and NPV (40%). The hemagglutination inhibition test and Toxorhynchites splendens inoculation technique for virus isolation were also similar in sensitivity (68%) and NPV (25%). The virus antigen detection technique by IFA in cells of cerebrospinal fluid (CSF) was the least sensitive (58%). The distinct advantage of the acute serum ELISA is that it can be carried out on a single finger-prick blood specimen. The IFA on CSF cells is the most rapid diagnostic test since it requires only 2-3 hours to complete. Therefore, both these tests also offer potential tools for JE surveillance programs.
Gajanana
A
A
Center for Research in Medical Entomology, Chinna Chokkikulam, Madurai, India.
Samuel
P P
PP
Thenmozhi
V
V
Rajendran
R
R
D000328:Adult; D002648:Child; D002675:Child, Preschool; D004664:Encephalitis Virus, Japanese / Q000276:immunology; D004672:Encephalitis, Japanese / Q000134:cerebrospinal fluid / Q000175:diagnosis* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology; D007194:India; D007223:Infant
D007075:Immunoglobulin M