Evaluation of current diagnostic methods for COVID-19

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the agent responsible for the coronavirus disease of 2019 (COVID-19), which triggers lung failure, pneumonia, and multi-organ dysfunction. This enveloped, positive sense and single-stranded RNA virus can be transmitted through aerosol droplets, direct and indirect contacts. Thus, SARS-CoV-2 is highly contagious and has reached a pandemic level in a few months. Since COVID-19 has caused numerous human casualties and severe economic loss posing a global threat, the development of readily available, accurate, fast, and cost-effective diagnostic techniques in hospitals and in any places where humans spread the virus is urgently required. COVID-19 can be diagnosed by clinical findings and several laboratory tests. These tests may include virus isolation, nucleic acid-based molecular assays like real-time polymerase chain reactions, antigen or antibody-based immunological assays such as rapid immunochromatographic tests, enzyme-linked immunosorbent assays, immunofluorescence techniques, and indirect fluorescent antibody techniques, electrochemical sensors, etc. However, current methods should be developed by novel approaches for sensitive, specific, and accurate diagnosis of COVID-19 cases to control and prevent this outbreak. Thus, this review will cover an overview and comparison of multiple reports and commercially available kits that include molecular tests, immunoassays, and sensor-based diagnostic methods for diagnosis of COVID-19. The pros and cons of these methods and future perspectives will be thoroughly evaluated and discussed.

Current and innovative methods for the diagnosis of COVID‑19 infection (Review)

“…Apart from these approaches, other methods have been developed, including biosensors, CRISPR/Cas-based tests, nucleic acid isothermal amplification methods, electron microscopy, etc. ( 25 , 95 ).…”

“…At present, NGS is not used for diagnostic purposes, but for molecular epidemiology and for the discovery of novel molecular variants. Indeed, its diagnostic application is limited due to the high costs of the analysis, the requirement of expensive technologies and the need for highly trained personnel with molecular and bioinformatics skills ( 25 ). Despite the high procedural costs, some companies have proposed commercial tests for the sequencing of SARS-CoV-2 through NGS platforms.…”

“…Each of these three types of diagnostic tests can be applied at a precise moment of infection. Of note, only kits, reagents and molecular probes validated by the Centers for Diseases Control and Prevention (CDC) and the World Health Organization (WHO) and approved at the American and European level by the FDA and by the EMA can be used for diagnostic purposes ( 25 ).…”

Rigid monoclonal antibodies improve detection of SARS-CoV-2 nucleocapsid protein

“…The ongoing SARS-CoV-2 pandemic has highlighted the need for sensitive point-of-care diagnostics (POCs), which are primarily antibody-based technologies ( Alpdagtas et al, 2020 ). Currently, mAbs are widely used to detect antigen molecules, including the nucleocapsid protein from SARS-CoV-2.…”

“…The US Food and Drug Administration recently authorized a lateral flow antigen test as the first over-the-counter, fully at-home diagnostic test for the qualitative detection of SARS-CoV-2 nucleocapsid antigens ( FDA, 2020 ). However, there is an urgent need to improve the detection limit of these diagnostic devices that use various types of colorimetric mAb-based assays ( Alpdagtas et al, 2020 ). Multiple approaches, like florescent immunoassays ( Ahn et al, 2009 ; Loeffelholz & Tang, 2020 ; Wang et al, 2020 ), nanoparticle luminescence ( Hesari & Ding, 2020 ; Teengam et al, 2017 ) or magnetic beads as the antibody support surface ( Fabiani et al, 2021 ), are used to enhance the detection of antigen.…”