title: Multi-country evaluation of the sensitivity and specificity of two commercially-available NS1 ELISA assays for dengue diagnosis.
abstract: BACKGROUND
  Early diagnosis of dengue can assist patient triage and management and prevent unnecessary treatments and interventions. Commercially available assays that detect the dengue virus protein NS1 in the plasma/serum of patients offers the possibility of early and rapid diagnosis.
  
  
  RESULTS
  The sensitivity and specificity of the Pan-E Dengue Early ELISA and the Platelia Dengue NS1 Ag assays were compared against a reference diagnosis in 1385 patients in 6 countries in Asia and the Americas. Platelia was more sensitive (66%) than Pan-E (52%) in confirmed dengue cases. Sensitivity varied by geographic region, with both assays generally being more sensitive in patients from SE Asia than the Americas. Both kits were more sensitive for specimens collected within the first few days of illness onset relative to later time points. Pan-E and Platelia were both 100% specific in febrile patients without evidence of acute dengue. In patients with other confirmed diagnoses and healthy blood donors, Platelia was more specific (100%) than Pan-E (90%). For Platelia, when either the NS1 test or the IgM test on the acute sample was positive, the sensitivity versus the reference result was 82% in samples collected in the first four days of fever. NS1 sensitivity was not associated to disease severity (DF or DHF) in the Platelia test, whereas a trend for higher sensitivity in DHF cases was seen in the Pan-E test (however combined with lower overall sensitivity).
  
  
  CONCLUSIONS
  Collectively, this multi-country study suggests that the best performing NS1 assay (Platelia) had moderate sensitivity (median 64%, range 34-76%) and high specificity (100%) for the diagnosis of dengue. The poor sensitivity of the evaluated assays in some geographical regions suggests further assessments are needed. The combination of NS1 and IgM detection in samples collected in the first few days of fever increased the overall dengue diagnostic sensitivity.
authors.affiliation: Virology Department, Pan American Health Organization/World Health Organization Collaborating Center, Instituto de Medicina Tropical Pedro Kouri, Habana, Cuba.
authors.forename: Maria G
authors.initials: MG
authors.lastname: Guzman
authors.forename: Thomas
authors.initials: T
authors.lastname: Jaenisch
authors.forename: Roger
authors.initials: R
authors.lastname: Gaczkowski
authors.forename: Vo Thi
authors.initials: VT
authors.lastname: Ty Hang
authors.forename: Shamala Devi
authors.initials: SD
authors.lastname: Sekaran
authors.forename: Axel
authors.initials: A
authors.lastname: Kroeger
authors.forename: Susana
authors.initials: S
authors.lastname: Vazquez
authors.forename: Didye
authors.initials: D
authors.lastname: Ruiz
authors.forename: Eric
authors.initials: E
authors.lastname: Martinez
authors.forename: Juan C
authors.initials: JC
authors.lastname: Mercado
authors.forename: Angel
authors.initials: A
authors.lastname: Balmaseda
authors.forename: Eva
authors.initials: E
authors.lastname: Harris
authors.forename: Efren
authors.initials: E
authors.lastname: Dimano
authors.forename: Prisca Susan A
authors.initials: PS
authors.lastname: Leano
authors.forename: Sutee
authors.initials: S
authors.lastname: Yoksan
authors.forename: Elci
authors.initials: E
authors.lastname: Villegas
authors.forename: Herminia
authors.initials: H
authors.lastname: Benduzu
authors.forename: Iris
authors.initials: I
authors.lastname: Villalobos
authors.forename: Jeremy
authors.initials: J
authors.lastname: Farrar
authors.forename: Cameron P
authors.initials: CP
authors.lastname: Simmons
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000914:Antibodies, Viral / Q000097:blood; D000956:Antigens, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D007223:Infant; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D017361:Viral Nonstructural Proteins / Q000097:blood*; D014773:Virology / Q000379:methods*; D055815:Young Adult
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic; D017361:Viral Nonstructural Proteins
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