Evaluation of a novel immuno-magnetic assay technology for rapid detection of dengue NS1 antigen

Partha Roy, Ravi Gaur, Ankita Anand


Background: Serological diagnosis of dengue fever is based on the detection of NS1 antigen and further confirmed by the assay of dengue IgM and IgG. Rapid Diagnostic Tests (RDTs) are no longer recommended for use by the Government of India. However, there is a requirement of rapid results without compromising on the test quality. Accordingly, we undertook an evaluation of a novel cartridge-based system employing a unique table-top diagnostic device for dengue NS1 antigen by BluSense Diagnostics incorporating a patented Immuno-Magnetic Assay (IMA).

Methods: A total of 309 samples were tested on unlinked anonymous basis. Each sample was tested using NS1 Ag ELISA (Microlisa, J. Mitra), ViroTrack and NS1 RDT (SD Alere) and results were recorded. Discordant samples were further tested by dengue NS1 AG ELISA (Panbio) and dengue IgG/IgM Maclisa (J. Mitra).

Results: When compared with approved ELISA kits used globally the Virotrack test returned a sensitivity of 94.74%; specificity of 97.44%; PPV of 97.30%; NPV of 95% and accuracy of 96.10%. Hourly throughput is 5-6 samples.

Conclusions: The Virotrack system is highly suitable as a POCT module in HCFs with low to moderate workload that employs novel technology, is rapid, user friendly and comparable to the ELISA in sensitivity and specificity. The equipment is user friendly and can work both on plasma/serum and whole blood. Model with multiple modules (3-4) will improve the throughput and turnaround time. Evaluation of this novel technology has been done in India for the first time.


BluBox, Dengue NS1 Ag, Immuno-magnetic assay, Point of care testing, Virotrack

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National guidelines clinical management_dengue1. Publications and information resources. Available at: national_guidelines_clinical_management_dengue1.pdf?ua=1. Accessed 15 Nov 2019.

Guidelines for clinical management of dengue fever. Diseases, dengue, NVBDCP. Available at: Accessed 15 Nov 2019.

Biswas A, Pangtey G, Devgan V, Singla P, Murthy P, Dhariwal A et al. Indian national guidelines for clinical management of dengue fever. J Ind Med Assoc. 2015;113(12):196-206.

DTU Nanotech, Technical University of Denmark, Kongens Lyngby, Copenhagen, Denmark. Micro- and nanotechnology in new settings. Available at: Accessed 15 Nov 2019.

CIC NanoGUNE, San Sebastian, Spain. Nanomagnetism. Available at: nanomagnetism. Accessed 15 Nov 2019.

BluSense diagnostics, Copenhagen, Denmark. Nanoparticle based immunoassay technology. Available at: Accessed 15 Nov 2019.

Banerjee A, Paul UK, Bandyopadhyay A. Diagnosis of dengue fever: roles of different laboratory test methods. Int J Adv Medi. 2018 Mar 21;5(2):395-9.

World Health Organization. Global strategy for dengue prevention and control 2012-2020.

Gatteschi D, Sessoli R, Villain J. Molecular nanomagnets. Oxford University Press on Demand. 2006 Mar 2.

Donati F, Rusponi S, Stepanow S, W├Ąckerlin C, Singha A, Persichetti L, et al. Magnetic remanence in single atoms. Science. 2016 Apr 15;352(6283):318-21.

Ishikawa N, Sugita M, Wernsdorfer W. Nuclear spin driven quantum tunneling of magnetization in a new lanthanide single-molecule magnet: bis (phthalocyaninato) holmium anion. J Am Chem Soc. 2005 Mar 23;127(11):3650-1.

Yetisen AK, Akram MS, Lowe CR. based microfluidic point-of-care diagnostic devices. Lab Chip. 2013;13(12):2210-51.

Whitesides GM. The origins and the future of microfluidics. Nature. 2006 Jul;442(7101):368-73.