Recombinant DENV type 2 NS1 (patient M3, Fragment) [His]

Dengue remains an important public health problem in Indonesia. Rapid diagnosis of dengue infection is critical in disease management and control. A pan-dengue virus (DENV) RT-insulated isothermal (ii)PCR assay method, which is a field-deployable system, was evaluated in detection of DENV isolates and human serum samples collected in Indonesia in comparison with a DENV reference multiplex quantitative (q)RT-PCR assay system and a DENV NS1 antigen rapid test. RT-iiPCR and reference qRT-PCR showed comparable sensitivity in detecting DENV isolates of all four serotypes. Compared to composite results of serum samples (two out of the three methods giving the same result, ie 90 DENV positives and 69 DENV negatives), sensitivity, specificity and accuracy of the pan DENV RT-iiPCR assay was 100% [95% confidence interval (CI): 97-100], 100% (95% CI: 96-100) and 100% (95% CI: 98-100), respectively, reference multiplex qRT-PCR assay 98% (95% CI: 94-100), 98% (95% CI: 94-100) and 98% (95% CI: 95-100), respectively, and DENV NS1 antigen rapid test 89% (95% CI: 82-96), 81% (95% CI: 72-91) and 85% (95% CI: 80-91), respectively. Thus, this field-deployable battery-operated pan-DENV RT-iiPCR system should serve as an important tool to facilitate diagnosis of dengue infection in rural and remote communities of Indonesia and other developing countries.

Background: Due to the rapid geographic expansion, dengue has attracted much global attention. Hence, many research outputs have emanated from clinical and epidemiological studies. However, most of these studies, especially those from low- and middle-income countries, heavily relied on enzyme-linked immunosorbent assay (ELISA). Objective: In view of this, we sought to comment and remind dengue researchers within virology, immunology, and epidemiology disciplines regarding the limitations of ELISA protocols in establishing diagnosis of dengue virus (DENV) infections. Subsequently, we provided an update on the current diagnostic algorithm for dengue. Method: Extensive literature search was done using special key words on "PubMed", "Scopus", "Web of Science" and "Hinari". Suitable articles were selected and subjected to scrutiny for inclusion in this study. Result: It was discovered that over 90% of published articles from LMICs inferred about dengue mainly from available commercial serological kits, without further confirmation using more accurate, sensitive and specific protocols. In some instances (less than 5%), combination of either RNA positive and anti-DENV IgM or dengue NS1 and anti-DENV IGM were used to diagnose acute primary dengue; while presence anti-DENV IgG and DENV RNA were considered non-primary dengue. Conclusion: In view of the limitations of every protocol used for investigations of dengue virus infections, its necessary to utilize appropriate combination tests to differentiate primary from non-primary dengue in order to generate reliable clinical and epidemiological inferences.