COVID-19: Genomic structure, viral replication and pathophysiology

The whole world is facing a highly challenging and extremely difficult task of facing a pandemic of coronavirus disease-2019 (COVID-19) caused by a very deadly and highly contagious virus named by WHO as severe acute respiratory syndrome coronavirus-2 (SARS CoV-2). This dangerous virus originated probably from bats and through undetermined intermediate hosts entered humans and first reported in seafood market of Hubei province of Wuhan, China in December 2019. Covid-19 spreads very fast by personal contact with patients and by micro droplets generated by sneezing and coughing by the patients. Covid-19 has infected more than 3.2 million people across the globe and claimed more than 229000 deaths to date (30/04/2020). The virus spreads faster than its two ancestors which are Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle East Respiratory Syndrome Coronavirus (MERS-CoV), but has lower mortality then them. The spectrum of disease varies from asymptomatic to pneumonia, acute respiratory distress syndrome (ARDS) and multi organ dysfunction. The case fatality rate is estimated to range from 3 to 4%. Treatment is essentially supportive because of lack of definitive antiviral drugs or effective vaccine. As this disease is spreading across the continents very fast and due to lack of definitive treatment only way left is to prevent the infection is its containment. Prevention entails creating public awareness about this highly infectious disease, home isolation of suspected cases and those with mild illnesses and strict infection control measures at hospitals that include contact and droplet precautions. This review focuses on the genomic structure, viral replication and pathophysiology of SARS CoV-2 known till date as new studies are continuously shedding lights on the various aspects of this virus.