title: Evaluating the sensitivity of a commercial dengue NS1 antigen-capture ELISA for early diagnosis of acute dengue virus infection.
abstract: BACKGROUND
  The aim of this report is to establish an accurate diagnosis of acute dengue virus infection early, in order to provide timely information for the management of patients and early public health control of dengue outbreak.
  
  
  METHODS
  224 serum samples from patients with a clinical diagnosis of acute dengue infection, which were subsequently confirmed by laboratory tests, were used to evaluate the performance of a commercially-available dengue NS1 antigen-capture ELISA kit.
  
  
  RESULTS
  The dengue NS1 antigen-capture ELISA gave an overall sensitivity rate of 93.3 percent (209/224). The sensitivity rate was significantly higher in acute primary dengue (97.4 percent) than in acute secondary dengue (68.8 percent). In comparison, the virus isolation gave an overall positive isolation rate of 64.7 percent, with a positive rate of 70.8 percent and 28.1 percent, for acute primary dengue and acute secondary dengue, respectively. Molecular detection of dengue RNA by RT-PCR gave an overall positive detection rate of 63.4 percent, with a positive rate of 62.5 percent and 68.8 percent, for acute primary dengue and acute secondary dengue, respectively. Of the 224 acute serum samples from patients with laboratory-confirmed acute dengue infection, dengue IgM was detected in 88 specimens, comprising 68 acute primary dengue specimens and 20 acute secondary dengue specimens. NS1 antigen-capture ELISA kit gave an overall sensitivity rate of 88.6 percent in the presence of anti-dengue IgM and 96.3 percent in the absence of anti-dengue IgM.
  
  
  CONCLUSIONS
  Of the 224 acute serum samples, the sample ages of 166 acute serum samples are known. The positive detection rate of dengue NS1 antigen-capture ELISA, on the whole, was higher than the other three established diagnostic test methods for laboratory diagnosis of acute dengue infection.
authors.affiliation: The National Public Health Laboratory, Ministry of Health, Lot 1853 Kg Melayu, Sungai Buloh 47000, Malaysia.
authors.forename: V
authors.initials: V
authors.lastname: Kumarasamy
authors.forename: S K
authors.initials: SK
authors.lastname: Chua
authors.forename: Z
authors.initials: Z
authors.lastname: Hassan
authors.forename: A H A
authors.initials: AH
authors.lastname: Wahab
authors.forename: Y K
authors.initials: YK
authors.lastname: Chem
authors.forename: M
authors.initials: M
authors.lastname: Mohamad
authors.forename: K B
authors.initials: KB
authors.lastname: Chua
mesh_terms: D003716:Dengue Virus / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D019595:Severe Dengue / Q000175:diagnosis* / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000097:blood* / Q000276:immunology
chemical_list: D007074:Immunoglobulin G; D011933:Reagent Kits, Diagnostic; D017361:Viral Nonstructural Proteins