Comparison of the diagnostic accuracy of commercial NS1-based diagnostic tests for early dengue infection.
BACKGROUND
We compared the diagnostic accuracy and reproducibility of commercially available NS1-based dengue tests and explored factors influencing their sensitivities.


METHODS
Paired analysis of 310 samples previously characterized as positive (n = 218) and negative (n = 92) for viral isolation and/or RT-PCR and/or IgM seroconversion. Masked samples were tested by two observers with Platelia™ Dengue NS1 Ag, second generation Pan-E™ Dengue Early ELISA, SD Dengue NS1 Ag ELISA, Dengue NS1 Ag STRIP™, and SD BIOLINE™ Dengue Duo (NS1/IgM/IgG).


RESULTS
SD BIOLINE™ NS1/IgM/IgG had the highest sensitivity (80.7% 95%CI 75-85.7) with likelihood ratios of 7.4 (95%CI 4.1-13.8) and 0.21 (95%CI 0.16-0.28). The ELISA-format tests showed comparable sensitivities; all below 75%. STRIP™ and SD NS1 had even lower sensitivities (<65%). The sensitivities significantly decreased in samples taken after 3 days of fever onset, in secondary infections, viral serotypes 2 and 4, and severe dengue. Adding IgM or IgG to SD NS1 increased its sensitivity in all these situations.


CONCLUSIONS
The simultaneous detection of NS1/IgM/IgG would be potentially useful for dengue diagnosis in both endemic and non endemic areas. A negative result does not rule out dengue. Further studies are required to assess the performance and impact of early laboratory diagnosis of dengue in the routine clinical setting.
Grupo de Epidemiologia y Salud Poblacional (GESP) Escuela de Salud Publica, Facultad de Salud, Universidad del Valle, Cali, Colombia Calle 4b 36-140, Cali-Colombia. lyda1oso@gmail.com
Lyda
L
Osorio
Meleny
M
Ramirez
Anilza
A
Bonelo
Luis A
LA
Villar
Beatriz
B
Parra
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000914:Antibodies, Viral / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003715:Dengue / Q000175:diagnosis*; D003955:Diagnostic Tests, Routine / Q000379:methods*; D005260:Female; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011933:Reagent Kits, Diagnostic; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D017361:Viral Nonstructural Proteins / Q000097:blood*; D014773:Virology / Q000379:methods*; D055815:Young Adult
D000914:Antibodies, Viral; D011933:Reagent Kits, Diagnostic; D017361:Viral Nonstructural Proteins