title: Evaluation of two commercially available ELISAs for the diagnosis of Japanese encephalitis applied to field samples.
abstract: OBJECTIVE
  To compare two commercially available kits, Japanese Encephalitis-Dengue IgM Combo ELISA (Panbio Diagnostics) and JEV-CheX IgM capture ELISA (XCyton Diagnostics Limited), to a reference standard (Universiti Malaysia Sarawak - Venture Technologies VT ELISA).
  
  
  METHODS
  Samples were obtained from 172/192 children presenting to a site in rural India with acute encephalitis syndrome.
  
  
  RESULTS
  Using the reference VT ELISA, infection with Japanese encephalitis virus (JEV) was confirmed in 44 (26%) patients, with central nervous system infection confirmed in 27 of these; seven patients were dengue seropositive. Of the 121 remaining patients, 37 (31%) were JEV negative and 84 (69%) were JEV unknown because timing of the last sample tested was <10 day of illness or unknown. For patient classification with XCyton, using cerebrospinal fluid alone (the recommended sample), sensitivity was 77.8% (59.2-89.4) with specificity of 97.3% (90.6-99.2). For Panbio ELISA, using serum alone (the recommended sample), sensitivity was 72.5% (57.2-83.9) with specificity of 97.5% (92.8-99.1). Using all available samples for patient classification, sensitivity and specificity were 63.6% (95% CI: 48.9-76.2) and 98.4% (94.5-99.6), respectively, for XCyton ELISA and 75.0% (59.3-85.4) and 97.7% (93.3-99.2) for Panbio ELISA.
  
  
  CONCLUSIONS
  The two commercially available ELISAs had reasonable sensitivities and excellent specificities for diagnosing JEV.
authors.affiliation: Brain Infections Group, University of Liverpool, Liverpool, UK. pennylewthwaite@doctors.org.uk
authors.forename: Penny
authors.initials: P
authors.lastname: Lewthwaite
authors.forename: M Veera
authors.initials: MV
authors.lastname: Shankar
authors.forename: Phaik-Hooi
authors.initials: PH
authors.lastname: Tio
authors.forename: Janet
authors.initials: J
authors.lastname: Daly
authors.forename: Anna
authors.initials: A
authors.lastname: Last
authors.forename: R
authors.initials: R
authors.lastname: Ravikumar
authors.forename: Anita
authors.initials: A
authors.lastname: Desai
authors.forename: V
authors.initials: V
authors.lastname: Ravi
authors.forename: Jane M
authors.initials: JM
authors.lastname: Cardosa
authors.forename: Tom
authors.initials: T
authors.lastname: Solomon
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D004672:Encephalitis, Japanese / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011933:Reagent Kits, Diagnostic; D012015:Reference Standards; D012680:Sensitivity and Specificity
chemical_list: D011933:Reagent Kits, Diagnostic