[Evaluation of the SD Dengue Duo diagnosis system for detection of NS1 protein and IgM and IgG dengue antibodies].

Abstract

Introduction: SD Dengue Duo (Standard Diagnosis) commercial kit is an immunochromatographic rapid test that detects NS1 protein and IgG/IgM dengue antibodies simultaneously.

Objective: to evaluate the operational and functional characteristics of this system for the detection of virological and serological markers.

Methods: sera panel was made up by 161 samples, 113 from patients with clinically and serologically confirmed dengue caused by any of the four dengue virus serotypes and 48 negative samples. All these samples were tested by SD Dengue Duo Kit and by Platelia Dengue NSI Ag, IgM Capture ELISA and ELISA Inhibition Method used as reference assays.

Results: the evaluated kit showed a 57.75% sensitivity for the detection of NS1 protein, false negatives were detected in samples collected 5 days or more after fever onset in secondary infection cases. IgM detection showed 96.0% sensitivity and 98.4% specificity. Furthermore, high agreement (95.7%) in classifying dengue infection types (primary or secondary infections) was observed. The global study of the 3 markers, the sensitivity rose to 100%.

Conclusions: SD Dengue Duo is a simple, easy and rapid assay; it does not require additional equipment, can be used for acute and convalescence serum samples and offers a good alternative for dengue diagnosis in those laboratories where a complete dengue virus diagnosis is difficult to perform.