title: The diagnostic sensitivity of dengue rapid test assays is significantly enhanced by using a combined antigen and antibody testing approach.
abstract: BACKGROUND
  Serological tests for IgM and IgG are routinely used in clinical laboratories for the rapid diagnosis of dengue and can differentiate between primary and secondary infections. Dengue virus non-structural protein 1 (NS1) has been identified as an early marker for acute dengue, and is typically present between days 1-9 post-onset of illness but following seroconversion it can be difficult to detect in serum.
  
  
  OBJECTIVE
  To evaluate the performance of a newly developed Panbio® Dengue Early Rapid test for NS1 and determine if it can improve diagnostic sensitivity when used in combination with a commercial IgM/IgG rapid test.
  
  
  METHODS
  The clinical performance of the Dengue Early Rapid was evaluated in a retrospective study in Vietnam with 198 acute laboratory-confirmed positive and 100 negative samples. The performance of the Dengue Early Rapid in combination with the IgM/IgG Rapid test was also evaluated in Malaysia with 263 laboratory-confirmed positive and 30 negative samples.
  
  
  RESULTS
  In Vietnam the sensitivity and specificity of the test was 69.2% (95% CI: 62.8% to 75.6%) and 96% (95% CI: 92.2% to 99.8) respectively. In Malaysia the performance was similar with 68.9% sensitivity (95% CI: 61.8% to 76.1%) and 96.7% specificity (95% CI: 82.8% to 99.9%) compared to RT-PCR. Importantly, when the Dengue Early Rapid test was used in combination with the IgM/IgG test the sensitivity increased to 93.0%. When the two tests were compared at each day post-onset of illness there was clear differentiation between the antigen and antibody markers.
  
  
  CONCLUSIONS
  This study highlights that using dengue NS1 antigen detection in combination with anti-glycoprotein E IgM and IgG serology can significantly increase the sensitivity of acute dengue diagnosis and extends the possible window of detection to include very early acute samples and enhances the clinical utility of rapid immunochromatographic testing for dengue.
authors.affiliation: Research and Development, Alere, Brisbane, Australia.
authors.forename: Scott R
authors.initials: SR
authors.lastname: Fry
authors.forename: Michelle
authors.initials: M
authors.lastname: Meyer
authors.forename: Matthew G
authors.initials: MG
authors.lastname: Semple
authors.forename: Cameron P
authors.initials: CP
authors.lastname: Simmons
authors.forename: Shamala Devi
authors.initials: SD
authors.lastname: Sekaran
authors.forename: Johnny X
authors.initials: JX
authors.lastname: Huang
authors.forename: Catriona
authors.initials: C
authors.lastname: McElnea
authors.forename: Chang-Yi
authors.initials: CY
authors.lastname: Huang
authors.forename: Andrea
authors.initials: A
authors.lastname: Valks
authors.forename: Paul R
authors.initials: PR
authors.lastname: Young
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Cooper
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D019411:Clinical Laboratory Techniques / Q000379:methods*; D003715:Dengue / Q000175:diagnosis*; D003716:Dengue Virus / Q000276:immunology*; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014744:Vietnam; D017361:Viral Nonstructural Proteins / Q000097:blood; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D017361:Viral Nonstructural Proteins