Overview of coronavirus - Understanding origin, pathogenesis, clinical features & diagnostic approach to COVID-19 in Indian scenario

Abstract

In early December 2019, an outbreak of novel coronavirus (2019-nCoV) or the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) as it is now called, occurred in Wuhan City, Hubei Province, China. On January 30, 2020 the World Health Organization declared the outbreak as a Public Health Emergency of International Concern. Vaccines to prevent human coronavirus infections are not yet available. Coronavirus disease 2019 (COVID-19) spreads primarily when people are in close contact with small droplets produced by an infected person, identified as “super spreaders”. COVID-19 can be fatal among high-risk groups patients >60 yr. The envelope spike “S” protein receptor binding domain of SARS-CoV-2 use host receptor angiotensin-converting enzyme 2 (ACE2) to enter the cells of airway epithelium and alveolar type 2 (AT2) pneumocytes, and pulmonary cells. The most common clinical features are fever (80-90%), cough (60-80%) and breathlessness (18-46%). The other symptoms include myalgia, sore throat, loss of taste and smell, headache, nausea, vomiting and diarrhoea. Infection control practices to be followed stringently by Health Care Workers (HCW). Standard precautions to be maintained. Specimen to be packed in triple container packing. Cold temperature to be maintained during transport and storage. Laboratory tests of COVID-19 are broadly categorized into two methods: (1) Nucleic acid based assay: RT-PCR, TrueNAT, CBNAAT & (2) Immunoassay: Can be broadly divided into 2 types: Antigen based assay: Rapid antigen test, Antibody based assay: enzyme-linked immunosorbent assay (ELISA).

Keywords

• coronavirus
• covid-19
• laboratory diagnosis
• sars-cov-2