An Update on the Recent Diagnostic Modalities of SARS-CoV-2: A Review

The pandemic of respiratory viral pneumonia initiated as an outbreak during December 2019, at the Hubei region, China. The demanding research work conducted by the scientific community across the globe identified the causative agent as Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). The Case Fatality Rate (CFR) is high for the infection. Laboratory diagnosis of infectious diseases has an integral role in case surveillance, diagnosis, treatment and prevention. SARS-CoV-2 is a positive sense single stranded Ribonucleic Acid (RNA) virus grouped under the order Nidovirales, family Coronaviridae, and subfamily Orthocoronavirinae. The structural proteins are spike protein (S), membrane protein (M), nucleocapsid protein (N), and the envelope protein (E). The common symptoms are fever, cough, dyspnoea, fatigue, headache, muscle pain, anosmia and ageusia. The less common symptoms are sore throat, congestion, nausea, vomiting and diarrhoea. Sample collection is a critical step in the laboratory diagnosis of SARS-CoV-2 infection. The molecular methods used for diagnosis of SARS-CoV-2 are Real time Reverse Transcription Polymerase Chain Reaction (r-RT-PCR), Reverse Transcription Loop Mediated Isothermal Amplification (RT-LAMP), digital PCR, Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) based assay and sequencing methods. The antigen and antibody detection methods supplement the molecular tests. Although, a huge array of tests are available, the pertinent choice of diagnostic test is crucial. The molecular detection methods are highly sensitive, accurate and reliable.