Recombinant Dengue virus type 3 NS1 protein

ELISAs and rapid diagnostic tests (RDTs) are widely used for diagnosing dengue virus (DENV) infection. Using 138 single blood samples, we compared the ability to detect non-structural (NS)-1 antigen and anti-DENY IgM/IgG antibodies among (1) DENV Detect NS1 ELISA, DENV Detect IgM capture ELISA and DENV Detect IgG ELISA (InBios International, Inc.); (2) Anti-Dengue virus IgM Human ELISA and Anti-Dengue virus IgG Human ELISA (Abeam); (3) Dengue virus NS1 ELISA, Anti-Dengue virus ELISA (IgM) and Anti-Dengue virus ELISA (IgG) (Euroimmun); (4) Asan Easy Test Dengue NS1 Ag 100 and Asan Easy Test Dengue IgG/IgM (Asan Pharm); (5) SD BIOLINE Dengue Duo (Standard Diagnostics); and (6) Ichroma Dengue NS1 and Ichroma Dengue IgG/IgM (Boditech Med). For NS1 antigen detection, InBios and Euroimmun showed higher sensitivities (100%) than the RDTs (42.9-64.3%). All tests demonstrated variable sensitivities for IgM (38.1-90.5%) and IgG (65.7-100.0%). InBios and Boditech Med demonstrated higher sensitivity (95.6% and 88.2%, respectively) than the other tests for combined NS1 antigen and IgM antibody. Five NS1 antigen tests had good agreement (92.8-98.6%) without showing positivity for chikungunya. However, all IgG tests demonstrated potential false-positivity with variable ranges. Clinical laboratories should note performance variations across tests and potential cross-reactivity.

Dengue has caused a significant public health impact globally. With the diverse genetic of the causative viruses, analysis of dengue virus (DENV) genomes is important to supplement epidemiological data with information that can be used to reconstruct the history of epidemics in time and space. We have reported the clinical and virological characteristics of dengue in Surabaya, Indonesia and revealed the presence of all four DENV serotypes and the predominance of DENV-1. The further classification of Surabaya DENV-1 into two different genotypes warrants in-depth genomic analysis to study the dynamics of both genotypes and their contribution to virus evolution, virus transmission, and disease. We performed full-length genome sequencing to nine isolates' representatives from DENV-1 Genotype I and Genotype IV. Phylogenetic and evolutionary analyses suggested the more recent introduction of Genotype I viruses compared to the more endemic Genotype IV. Comparative analysis of Surabaya DENV-1 genomes and other sequences available publicly revealed that the majority of the DENV-1 codons were under strong purifying selection, while seven codon sites identified to be under positive selection. We highlight a unique codon site under the positive pressure in the NS1 gene of DENV-1. Our results provide additional genomic data of DENV from Indonesia that may contribute to the better understanding of dengue disease dynamics.