
Coronavirus disease is a fatal infectious disease caused by the novel Coronavirus (COVID-19). It creates severe acute respiratory syndrome Coronavirus 2 (Sars-CoV-2).
The first outbreak of the virus was reported in the city of Wuhan, China by the WHO on 31st December 2019.
The viruses are obligatory parasitic in nature and take over the host machinery to replicate itself. Soon enough, when the viral infection increases, the host body becomes weak against the virus and reaches to a fatal condition.
The first outbreak of the virus was reported in the city of Wuhan, China by the WHO on 31st December 2019.
The viruses are obligatory parasitic in nature and take over the host machinery to replicate itself. Soon enough, when the viral infection increases, the host body becomes weak against the virus and reaches to a fatal condition.

Coronavirus is an RNA virus and is antigenically similar to humans and cattle. The virus causes independent epidemics and is hard to isolate. The SARS-CoV-2 particles are spherical and have spikes proteins protruding from their surface. The outer protection regarded as the envelope has membrane (M), envelope (E) and spike (S). The E:S:M present in the lipid bilayer has a ratio of 1:20:300. The spike gets attached to the human cells and then lead to a structural conformation leading the proper fusion with the cell membrane of the host cell.
The viruses attain an enveloped structure with a single-stranded RNA, i.e. positive sense. The nucleocapsid residing in the cells has beads-on-a-string type conformation. This envelope actually protects the virus present outside the host cell. The genetic material has a nucleoprotein captured inside the capsid of the matrix protein. An electron microscope shows a similarity of the COVID-19 virus with the coronaviruses such as MERS and SARS with a distinctive crown-like appearance. The envelope has a diameter of 85 nm with each spike having a 20 nm length. The electron micrographs have distinct electron-dense shells that are opaque in nature.
The viruses attain an enveloped structure with a single-stranded RNA, i.e. positive sense. The nucleocapsid residing in the cells has beads-on-a-string type conformation. This envelope actually protects the virus present outside the host cell. The genetic material has a nucleoprotein captured inside the capsid of the matrix protein. An electron microscope shows a similarity of the COVID-19 virus with the coronaviruses such as MERS and SARS with a distinctive crown-like appearance. The envelope has a diameter of 85 nm with each spike having a 20 nm length. The electron micrographs have distinct electron-dense shells that are opaque in nature.

In December 2019, the first COVID-19 case emerged in the city of Wuhan, China. Within three months, there were nearly 1 million cases of people infected with the virus, among which 50,000 have died. The NIAID COVID-19 research was based on the earlier versions of the Coronavirus, such as the Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS).
In February 2003, the first SARS-CoV infection was reported in Asia. Within four months, 26 countries worldwide have cases from SARS. But since 2004, there have been no active cases. The SARS-CoV was the first highly pathogenic human CoV outbreak in the 21st century.
In September 2012, the first case of MERS was reported in Saudi Arabia and soon infected 27 other countries. Infected people have shown symptoms of acute respiratory illness, fever, cough and breathing problems. In 2020, WHO reposted laboratory-confirmed 2519 cases of MERS with 866 deaths. The SARS-CoV has been spread from infected civets to the healthy individual, whereas the MERS-CoV spread from infected dromedary camels to the healthy people.
In February 2003, the first SARS-CoV infection was reported in Asia. Within four months, 26 countries worldwide have cases from SARS. But since 2004, there have been no active cases. The SARS-CoV was the first highly pathogenic human CoV outbreak in the 21st century.
In September 2012, the first case of MERS was reported in Saudi Arabia and soon infected 27 other countries. Infected people have shown symptoms of acute respiratory illness, fever, cough and breathing problems. In 2020, WHO reposted laboratory-confirmed 2519 cases of MERS with 866 deaths. The SARS-CoV has been spread from infected civets to the healthy individual, whereas the MERS-CoV spread from infected dromedary camels to the healthy people.

The transmission of the COVID-19 virus spreads via respiratory droplets from an infected body to a healthy body. It is a respiratory infection and affects an individual via the droplets (less than 5 micrometres to 10 micrometres in diameter) or the contact routes. If any individual is in close contact with the infected person (within 1 m of distance) then the risk of mucosal exchange, conjunctiva increases leading to the infection. The infection can be spread by airborne transmission along with the presence of microbes in the droplets.
The most common mode of transmission involves when a healthy person comes in contact with the infected droplets or has touched a contaminated surface. They should avoid touching their mouth, nose and eyes followed by it.
The most common mode of transmission involves when a healthy person comes in contact with the infected droplets or has touched a contaminated surface. They should avoid touching their mouth, nose and eyes followed by it.