COVID-19: An Update on Pathogenesis and Treatment

Abstract

In 2019, a new virus -SARS-COV2 possibly emerged in China, which infected many people affecting mainly the respiratory system. SARS-COV2 gets transmitted by inhalation of droplets from the infected persons. Symptoms start to appear after the incubation period of the virus which ranges from 2 to 14 days. In most people, symptoms are usually mild such as fever, sore throat, cough, chest tightness and fatigue. In other people, the disease might progress into severe pneumonia leading to several fatal consequences. Treatment is usually supportive and the role of antiviral is not established yet. Home isolation for mild cases is important for the prevention of the transmission of infection. Although the rate of transmission of this virus is faster than other viruses from the family, such as MERS-CoV, it has a lower fatality rate. The main difference in the genome structure of this family, which makes it distinguishable from other viruses is its use of (+) ssRNA as genetic material, which comprise 5’ cap located at one end and 3' polyadenylation tract at the other end. During infection of an exposed host cell, viral-encoded protease cleaves the polyprotein that results from translation of 5’ open reading frame (ORF) of the genome, culminating in the release of multiple nonstructural proteins such as helicase (Hel), adenosine triphosphate (ATPase) and RNA-dependent RNA polymerase (Rep). These proteins are responsible for the replication process in addition to the syntheses of the sub genomic mRNA used as transcription template strand. In this review article, we discussed the transmission pathways, genetic sequence and current treatment approach of COVID-19.