Coronavirus and Coronavirus disease 2019 (COVID-19): An overview

Coronavirus and Coronavirus disease (COVID-19): An overview

Introduction

Coronaviruses are a group of associated viruses that cause diseases in humans, birds and other mammals. Coronavirus disease 2019 (COVID-19) is an infectious respiratory disease produced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) also known as a novel coronavirus (nCoV-2019). It was first detected in 2019. Other important Coronavirus that effect human are severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome coronavirus (MERSC).

Phylum	Incertae sedis
Order:	Nidovirales
Family:	Coronaviridae
Subfamily:	Orthocoronavirinae
Genus:	Betacoronavirus
Strains	Severe acute respiratory syndrome (SARS) and Middle east respiratory syndrome coronavirus, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)

Table: Taxonomy classification of novel Coronavirus (SARS-CoV-2)

Morphological characteristics of novel coronavirus (SARS-CoV-2)

"Coronavirus" name is derived from Latin word corona, meaning "crown" or "wreath".  It has large fringe, bulbous surface projections and viral spike peplomers, which are proteins on the external of the virus. The outer viral envelope comprises of a lipid bilayer where the membrane, envelope and spike structural proteins are attached

Coronavirus (SARS-CoV-2)

Origin of novel coronavirus (SARS-CoV-2): 

This disease was first recognized on 17 November 2019 at Wuhan, the capital city of China's Hubei region (Huanan Seafood Wholesale Market of Wuhan, through animal-to-human transmission)  

Host: 

The natural host of this virus is still unknown and is believed to have an animal origin e.g pangolins, Bats, etc. It is assumed human acquired infection from these animals, but research is still going on.

Occurrence and distribution of coronavirus:

Nowadays the infection and outbreak of SARS-CoV-2 are distributed throughout the world.   Till date, most effected countries are Italy, China, Iran, USA etc. In India, the first case of SARS-CoV-2 was reported in Kerala. Most numbers of the positive case reported states till date in India are Maharashtra, Kerala, and Uttar Pradesh etc.

Molecular and Genome information of coronavirus:

 In the genome analysis study of nCoV-2019 revealed that two viruses may have been combined. It is RNA molecule contains a positive-sense, single-stranded RNA genome with a genome size range for 30 to 34 kilobases (largest among RNA viruses). It contains at least 15 genes including the S gene which codes for surface proteins. Molecular phylogenetic analysis showed nCoV is 88% similar to bat derived SAR- like coronavirus 79% close to SAR-Cov and 50% similar to MERS‐Cov (Middle East respiratory syndrome coronavirus)

Sign and symptoms of coronavirus:

 The following sign and symptoms are reported from the person who has received SARS-CoV-2 infection.

·         Higher Fever

·         Dry Cough

·         Fatigue

·         Sore throat

·         Shortness of breath

·         Sputum production

The incubation period for SARS-CoV-2 is normally 5 to 6 days but may range from 2 to 14 days. On 11 March 2020 World Health Organization (WHO) declared coronavirus outbreak a pandemic and Public Health Emergency of International Concern (PHEIC) on 30 January 2020

Diagnosis and testing of coronavirus (SARS-CoV-2):

·         Polymerase chain reaction (PCR) tests

·         rt polymerase chain reaction (rtPCR)

·         Serological techniques

Mode of Transmission of coronavirus:

·         Human to human contact (personal contact)

·         Cough and sneeze through air

·         Contaminated object

Prevention of coronavirus:

·         Keep personal distance from the infected person

·         Wash your hand regularly with sanitizers or soap  or 70% alcohol

·         Wear face mask and always cover your mouth while coughing or sneezing.

Mortality rate of coronavirus: 

·  It is mortality rate is very low i.e 2% to  8% and the highest is observed in older persons.

Treatments of coronavirus: 

So far no permanent treatment is available, however on trial basis antiviral drugs have been used are mentioned below.

·         Remdesivir

·         Chloroquine

·         Hydroxychloroquine,

·         Favipiravir

·         Ritonavir/lopinavir

·         Ritonavir/lopinavir

 A clinical trial of vaccine development has been started by different companies across the globe.