Coronavirus (Covid-19) Pandemic Crisis and Global Scenario: a Review

Coronavirus (Covid-19) Pandemic Crisis and Global Scenario: a Review

Himalayan J. Soc. Sci. & Humanities ISSN: 0975-9891 Vol. 15, (2020) 37-48 DOI: https://doi.org/10.51220/hjssh.v15i1.5 CORONAVIRUS (COVID-19) PANDEMIC CRISIS AND GLOBAL SCENARIO: A REVIEW SHRAVI SINGH1, SHREYANSH SINGH2, SHAILJA DOBRIYAL3, SUNIL KUMAR4 AND KUSUM DOBRIYAL5 1Rajshhree Medical College and Research Institute, Bareilly 2Rama Medical College, Hospital & Research Centre, NCR Delhi 3Saraswathi Institute of Medical Sciences, UP (Shivalik Apartment, Dehradun) 4Department of Zoology, D. A. V. (P.G.) College, Dehradun-248001 5Department of Sanskrit, HNB Garhwal University campus Pauri Garhwal-246001 *Corresponding Author Email: [email protected] Received: 28.11.2020; Revised: 15.12.2020; Accepted: 28.12. 2020 ©Society for Himalayan Action Research and Development Abstract: Novel coronavirus is a new strain that has not been previously found in human beings. Corona Virus Disease-2019 (COVID-19) is a respiratory disease that is originated in Wuhan, China during December, 2019 from where it spread to all over the world in more than 205 countries. Approximately 99 lac peoples were infected, about 1.4 lac death in India out of which more than 94 lac were recovered till December 2020. It was declared pandemic by the World Health Organization in March, 2020. The virus was found to infect people of all ages. It has resulted into more than 7crore infection in people and approximately 16 lac deaths globally till December 2020 and is continuing to cause further mortality. Its mortality rate is high on aged or co-morbid patients suffering from cardiovascular, diabetes, chronic respiratory disease and cancer. In India mortality rate is less than 2% may be due to genetic variation, immunity, feeding habits and specific socio-cultural traditions. Covid-19 pandemic has changed global economy, medical system and geopolitics. The present communication deals with a review on this pandemic, its current status and future perspectives. Keywords: COVID-19, Microbial diversity, Bio-weapon, Diagnosis, Genetic variations, Herd Immunity, Geopolitics, Traditional Medicine, Global Economy. Introduction Viruses are connecting link between living and non living. Chemically they have genetic material DNA or RNA with protein coat. They are non living outside the body and become active when come in contact of living organism. Among several types of human corona viruses, four types are most common (229E, NL63, OC43, and KHU1) and cause mild to moderate respiratory infections, like the common cold. Other two types, Severe Acute Respiratory Syndrome corona virus (SARS-CoV) and Middle East Respiratory Syndrome corona virus (MERS-CoV), can cause severe respiratory infections (Cheng et. al., 2007). The seventh type COVID-19 or (2019-nCoV) is a new strain recently discovered in China. ©SHARAD 37 http:// hjssh.sharadpauri.org Himalayan J. Soc. Sci. & Humanities ISSN: 0975-9891 Vol. 15, (2020) 37-48 DOI: https://doi.org/10.51220/hjssh.v15i1.5 Corona viruses were first discovered in the 1930s when an acute respiratory infection of domesticated chickens was shown to be caused by infectious bronchitis. In 1940s, two other animal corona viruses (mouse hepatitis virus, MHV and transmissible gastroenteritis virus, GTEV) were discovered. The Human corona viruses were discovered in the 1960s as human corona virus 229 E and OC 43 which caused common cold. SARS (severe acute respiratory syndrome) was another corona virus that circulated in China in 2003. MERS (Middle East Respiratory syndrome) was first reported in Saudi Arabia in 2012, which was also caused by a corona virus. The scientist, Zheng-Li Shi, of the Wuhan Institute of Virology, gave the name ‘nCoV-2019’, which is short for “novel corona virus of 2019”. She and her colleagues have been tracing corona virus and has warned that some of them are uniquely suited to cause human pandemics. Three strains of covid-19 (Type-A, Type-B and Type-C) have been identified till now globally. The corona virus belongs to kingdom Orthornavirae, phylum Pisuviricota, class Pisoniviricetes and family Coronaviridae. It is a single stranded RNA virus with genome size ranging of about 30 kb. It has spherical or pleomorphic enveloped particles with a nucleoprotein within a capsid comprised of matrix protein. The envelope bears club-shaped glycoprotein projections. Coronaviruses are named for these spikes that protrude from their surfaces, resembling a crown or the sun’s corona. These envelope glycoproteins are responsible for attachment to the host cell and also carry the main antigenic epitopes, particularly the epitopes recognized by neutralizing antibodies. Most human coronaviruses fall into one of two serotypes: OC43-like and 229E-like. They cause independent epidemics of indistinguishable disease. Coronavirus is made up of 29,903 nucleotides and its core is made up of 27 types of proteins. Several countries are involved in doing research on the structure and DNA sequencing of this virus. According to Professor Martin Hibi, from London school of Hygiene and Tropical Medicine, “For preparing the vaccine, scientists should target the S-protein, which helps in attachment with the human body present in the core of the virus.” The viral envelop consists of a lipid bilayer where the membrane (M), envelop (E) and spike (S) structural proteins are anchored. Inside the envelope, there is nucleocapsid, which is formed from multiple copies of the nucleocapsid protein (N), which are bound to the positive-sense single stranded RNA genome. The lipid bilayer envelope, membrane proteins, and nucleocapsid protect the virus when it is outside the host cell. Genome of novel coronavirus is small thus sequencing and analysis is simple (Lu et. al. 2020). Genome of COVID-19 RNA virus has been sequenced by China, USA, India and France. Council of Scientific and Industrial Research centers as CCMB Hyderabad and Institute of Genomics and Integrative Biology New Delhi are involved in virus genome studies. Infection begins when the viral spike (S) glycoprotein attaches to its complementary host cell receptor. After attachment, a protease of the host cell cleaves and activates the receptor-attached spike protein. Cleavage and activation allows the virus to enter into the host cell by direct diffusion or endocytosis. The virus particle is uncoated after entry into the cell and its genome enters in to the cell cytoplasm. The host ribosome translates the initial overlapping open reading frame of the virus genome and forms own a long polypeptide, which cleaves itself in to multiple nonstructural proteins. A number of the nonstructural proteins coalesce to form a multi protein replicase- transcriptase complex (RTC). The main replicase - transcriptase protein is the RNA dependent RNA polymerase (RdRp), which is directly involved in the replication and transcription of RNA from RNA strand. ©SHARAD 38 http:// hjssh.sharadpauri.org Himalayan J. Soc. Sci. & Humanities ISSN: 0975-9891 Vol. 15, (2020) 37-48 DOI: https://doi.org/10.51220/hjssh.v15i1.5 Figure 1. Structure of Coronavirus - COVID-19 The main function of the complex is to replicate the viral genome. RdRp directly mediates the synthesis of negative-sense genomic RNA from the positive-sense genomic RNA. This is followed by the replication of positive-sense genomic RNA from the negative-sense genomic RNA. The other important function of the complex is to transcribe the viral genome. The replicated positive-sense genomic RNA becomes the genome of the progeny viruses. The viral structural proteins S, E, and M move along the secretary pathway into Golgi intermediate compartment. There, the M proteins direct most protein-protein interactions required for assembly of viruses following its binding to nucleocapsid. Progeny viruses are then released from the host cell by exocytosis through secretary vesicles. Human Corona viruses Corona viruses vary significantly in risk factor. Some can kill more than 30% of those infected (MERS- CoV), and some are relatively harmless, such as the common cold. The major symptoms of Corona viruses are fever, sore throat and swollen adenoids occurring primarily in the winter and early spring seasons. Further it may cause pneumonia and bronchitis. The human coronavirus discovered in 2003, causes severe acute respiratory syndrome (SARS) having a unique pathogenesis because it causes both upper and lower respiratory tract infections (Cheng et. al., 2007). Six species of human corona viruses are known, with one species subdivided into two different strains, making seven strains of human corona viruses altogether. Four of these strains produce the generally mild symptoms like common cold (Human corona virus OC43 of genus β-CoV, HCoV-HKU1- β-CoV, HCoV-229E- α CoV and HCoV- NL63- α CoV). Three strains (two species) produce symptoms that are potentially severe; all three of these are β-CoV strains (MERS-CoV, SARS-CoV, SARS-CoV-2). Pathology Studies in both organ cultures and human volunteers show that corona viruses are extremely fastidious and grow only in differentiated respiratory epithelial cells. Infected cells become vacuolated, show damaged cilia, and may form syncytia. Cell damage triggers the production of inflammatory mediators, which increase nasal secretion and cause local inflammation and swelling. These responses in turn ©SHARAD 39 http:// hjssh.sharadpauri.org Himalayan J. Soc. Sci. & Humanities ISSN: 0975-9891 Vol. 15, (2020) 37-48 DOI: https://doi.org/10.51220/hjssh.v15i1.5 stimulate sneezing, obstruct the airway, and raise the temperature of the mucosa. ARDS (Acute Respiratory Distress Syndrome) is the main cause of death of COVID-19. ARDS is the common immune- pathological event for SARS-CoV-2. The main mechanisms for ARDS is the cytokine storm, the deadly uncontrolled systemic inflammatory response resulting from the release of large amounts of pro- inflammatory cytokines (IFN- α, IL-1, IL-6, IL-12, IL-18, IL-33, TNF- α, TGF) and chemokines (CCL-2, CCL-3, CCL-5, CXCL-8, CXCL-9, CXCL-10) by immune effecter cells in SARS-CoV-2 infection. Epidemiology The epidemiology of coronavirus colds has been little studied.

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