DENV type 3 NS1 (50 kDa)

Dengue is an important arboviral disease of tropical and subtropical regions, with significant morbidity and mortality. Dengue virus is antigenically classified into four serotypes, which are further classified into 4-5 genotypes based on their genetic diversity. Since genotypes vary in their virulence, their detection and analysis of spatial and temporal transition are essential. We utilized sequence information from the E-NS1 gene region for molecular and phylogenetic characterization of dengue viruses isolated from dengue patients between 2007 and 2009. All four serotypes and multiple genotypes were detected, with predominance and emergence of DENV-1 genotype V. Phylogenetic analysis revealed the emergence of DENV-1 genotype V from India for the first time, which has replaced the earlier circulating genotype III and genotype I. The circulation of multiple genotypes and genotype replacement is critical, since genotypes vary in their virulence, and this should be a point of concern for healthcare agencies.

Dengue non-structural protein 1 (NS1 DENV) is considered a biomarker for dengue fever in an early stage. A sensitive and rapid assay for distinguishing positive from negative dengue infection samples is imperative for epidemic control and public health in tropical regions because it enables the development of instantaneous updatable databases and effective surveillance systems. Presently, we successfully report, for the first time, the use of the electrochemical capacitive method for the detection of NS1 DENV biomarker in human serum samples. By using a ferrocene-tagged peptide modified surface containing anti-NS1 as the receptor, it was possible to differentiate positive from negative samples with a p < 0.01 in a reagentless and label-free capacitive format. This capacitive assay had a cut-off of 1.36% (confidence interval of 99.99%); it therefore opens new avenues for developing miniature label-free electrochemical devices for infectious diseases.