title: Use of saliva for early dengue diagnosis.
abstract: BACKGROUND
  The necessity of a venous blood collection in all dengue diagnostic assays and the high cost of tests that are available for testing during the viraemic period hinder early detection of dengue cases and thus could delay cluster management. This study reports the utility of saliva in an assay that detects dengue virus (DENV)-specific immunoglobulin A (Ig A) early in the phase of a dengue infection.
  
  
  RESULTS
  Using an antigen capture anti-DENV IgA (ACA) ELISA technique, we tested saliva samples collected from dengue-confirmed patients. The sensitivity within 3 days from fever onset was over 36% in primary dengue infections. The performance is markedly better in secondary infections, with 100% sensitivity reported in saliva samples from day 1 after fever onset. Serum and salivary IgA levels showed good correlation (Pearson's r = 0.69, p<0.001). Specificity was found to be 97%.
  
  
  CONCLUSIONS
  Our findings suggest that this technique would be very useful in dengue endemic regions, where the majority of dengue cases are secondary. The ACA-ELISA is easy to perform, cost effective, and especially useful in laboratories without sophisticated equipment. Our findings established the usefulness and reliability of saliva for early dengue diagnosis.
authors.affiliation: Environmental Health Institute, National Environment Agency, Singapore, Singapore.
authors.forename: Grace
authors.initials: G
authors.lastname: Yap
authors.forename: Bijon Kumar
authors.initials: BK
authors.lastname: Sil
authors.forename: Lee-Ching
authors.initials: LC
authors.lastname: Ng
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis* / Q000097:blood; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003715:Dengue / Q000175:diagnosis*; D003716:Dengue Virus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007070:Immunoglobulin A / Q000032:analysis* / Q000097:blood; D012463:Saliva / Q000276:immunology*; D012680:Sensitivity and Specificity; D044967:Serum / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D007070:Immunoglobulin A