BIRD'S-EYE VIEW OF CORONAVIRUS- Details, Symptoms, Treatment & it Impact on different Countries

Coronavirus belongs to a large family of viruses common in animals and humans. The microscopic virus SARS-CoV-2 / Novel COVID-19 has taken the form of pandemic and changed the world’s scenario thoroughly. 

Under microscopic examination, it has spikes of glycoprotein on its surface similar to the crown based on which it is named Corona. 

CLASSIFICATION OF SARS-CoV-2 VIRUS

ICTV (International Committee on Taxonomy of Viruses) put this virus in its defined taxonomic ranks for viruses. It has been put in family Coronaviridea which comprises two subfamilies, Torovirinae and Coronavirinae. 

This virus falls in the subfamily Coronavirinae which is further composed of four generes namely

• Alpha Coronavirus 
• Beta Coronavirus 
• Gamma Coronavirus 
• Delta Coronavirus 

Alpha & Beta CoVs are known to infect mammals i.e. animals and humans while Gamma & Delta infect avian creatures (Birds). The hierarchy of Novel COVID-19 from family up to Genus is shown below:

AILMENTS CAUSED BY CoVs

CoVs can cause respiratory, enteric (intestinal), hepatic (liver), neurological and cardiac ailments in various creatures like camels, cats, cows, felines, and humans. In the human host, those with underlying medical conditions, for example, diabetic or cardiac patients develop these ailments more severely than others if infected by coronaviruses and are more likely to confront death. 

However, ailments caused by CoVs differ from person to person depending on the type of CoV infecting and also the immune system as well as the medical conditions of the infected person.

HUMAN CoVs

As shown in the above hierarchy HCoV-229E and HCoV-NL63 (alphaCoVs) while in betaCoVs HCoV-OC43, HCoV-HKU1, SARS-CoV and MERS-CoV were known to infect humans before the outbreak of this SARS-CoV-2. 

It expresses the fact that mutation (changes) occurred in the genetic material of the pre-existing viruses of the family giving rise to a new virus SARS-CoV-2. 

Due to this evolution, it has also been called Novel Coronavirus. But in which organism and under what conditions this mutation occurred and how it reached humans is under research. Out of all the human CoVs, alphaCoVs and HCoV-OC43, HCoV-HKU1 from betaCoVs causes normal colds and upper respiratory tract diseases in immunocompetent (strong immune response) people. In immunodeficient subjects and the old, lower respiratory tract diseases can happen.

THREE HUMAN CoVs IN TWO DECADES

In two decades, 2001 ~ 2020 three human CoVs emerged; SARS-CoV (Severe Acute Respiratory Syndrome Coronavirus), MERS-CoV (the Middle East Respiratory Syndrome Coronavirus) and SARS-CoV-2. 

SARS-CoV was first reported in China in 2003 while MERS-CoV was first identified in Saudi Arabia in 2012. 

MERS-CoV & SARS-CoV had a higher mortality rate but lesser transmission. While SARS-CoV-2 has a lesser mortality rate than the pre-mentioned types but more infectious and has a higher transmission rate. 

The comparison of these three CoVs can be given as below where R_o is a reproduction number (Number of people infected by a virus carrier)

MORPHOLOGY

COVID-19 has a positive-strand RNA (Ribonucleic Acid) genome containing 29891 nucleotides which are building blocks of genetic material.

INTER SPECIES TRANSMISSION OF HUMAN CV

The primary vector of SARS-CoV & MERS-CoV was Bat!

From the bat, SARS-CV is transmitted to cats while the secondary host of MERS-CoV is Camels. From secondary vectors, these are transmitted to the dead-end host, Humans. But these causes no harm to bats due to their very strong immune system. 

Genomic examination of SARS-CoV-2 proposed that its RNA is 89 % the same as that of virus found in bats and 82 % as that of RNA of Human SARS-CV. Coronavirus separated from pangolins is 99 % similar to SARS-CoV-2 in membrane proteins, not in RNA, which is the most important part causing infections. 

But still, there is no final proposal about the intermediate host of SARS-CV-2.

BEGINNING OF COVID-19

The first case of SARS-CoV-2 was reported in Wuhan, the City of China on December 31, 2019. 

The initial patients had an association with the Hunan seafood market which confirmed the animal intermediate host. But which animal, it is uncertain to date. Then it spread at an exponential rate not only in china but in several other countries too as a result of international traveling and import-export of goods. 

On March 11, 2020, the WHO declared it a global pandemic that is going on till date but now diminishing to a great value.

SYMPTOMS OF CoV INFECTION

COVID-19 gives rise to different symptoms in different people. Some symptoms are more common than others which include fever, dry cough, sore throat, tiredness while aches and pains, troubled breathing, diarrhea, headache, loss of taste or smell, discoloration of fingers or toes are among the less common symptoms. 

CORONAVIRUS VACCINE/MEDICATION

To date the FDA (Food and Drug Administration) licensed COVID-19 and even SARS, MERS vaccine or medication have not been discovered. Hence, supportive medication is provided to the victims based on the symptoms that appeared. However, at present 40 teams of scientists from different countries are working day in day out to make an effective vaccine for it. It is hoped that in the future the world would have some vaccine to combat it.

CORONAVIRUS TREATMENT

At present, the only comparatively successful therapy for this infection is plasma therapy. In plasma treatment, plasma (blood liquor part) from the corona recovered person is extracted and injected into an infected person. The donor can give plasma after 14 days of recovery and is examined thoroughly before giving it to ensure that he or she is completely fit. The plasma of a recovered person is rich in antibodies (immune cells) which stay there for quite a long period even after recovery. These antibodies help the patients in battling the infection.

PREVENTIVE MEASURES

The virus has a very high transmission rate which may transfer from carrier person to surrounding people or from animals to humans and vice versa. “Prevention is better than cure”, hence we all are ethically responsible to adopt preventive measures for our's as well as our fellow beings' safety. Social distancing is the primary measure that signifies to avoid close and physical contact with others. One should stay 6 feet away from others to avoid catching or transferring of a virus. For coughing or sneezing, people should bend elbow to cover face so that droplets coming out of nose and mouth could not spread or inhaled by others. Wearing face mask when talking to others in time of need, either washing hands with soap or handwash for at least 20 seconds after every some time or using gloves when touching anything, touching high touch public items like a lift or ATM buttons with tissue paper are some other measures to prevent the spread of the virus. A healthy diet and more sleep time are other ways to improve immunity.

IMPACT OF CORONAVIRUS ON ECONOMY

The Coronavirus hit the world awfully putting malls, restaurants, shops, offices, in short, the whole international market shut down dwindling the world's economy. It badly affected especially small businesses, daily wagers, and private employees. Many companies downsized as a result of lockdown causing unemployment to a great value. It mainly caused a rise in dollar price and inflation in poor countries. 

IMPACT OF CORONAVIRUS ON INDIA

The virus was disastrous for India which caused the shutting down of offices like railways, planes, metros, roadways, and so forth. India had shut its entryways for outsiders and all the domestic flights were also halted affecting the economy of the Indian land. Indian Prime Minister Narendra Modi announced 21 days complete lockdown all across India on 24^th March 2020 implementing "section 144" to prevent the spread of the virus after the death of 10 corona patients.

IMPACT OF CORONAVIRUS ON AMERICA

America was not an exception to the adversities of Coronavirus. Residents were advised to stay at home; seashores, shopping centers were abandoned and like the rest of the world, it’s economy graph also dropped down.

IMPACT OF CORONAVIRUS ON CHINA

The city of “Wuhan” in the Hubei province of China was the initiating point of the virus across the globe and the most awful hit in China. After the outbreak in December 2019, China was under complete lockdown diminishing the overall economic activities and resumed on 24^th February 2020. The province of Hubei reported single-digit new cases for the first time on 28^th February since after the outbreak of the virus. There is a blame game in the world on the emergence of COVID-19 accusing China to artificially produce this bioweapon to become a superpower but no proof could be provided on this allegation.

 Dr. Li Wenliang, a Chinese doctor was the first one who informed his friends through the internet about the Coronavirus. He caught the virus himself and died in February 2020. But there are lots of rumors about him. Some information sources claim his message on the internet spread like fire due to which he was warned by Wuhan police for spreading false news. Other sources declare these as no more than rumors. What is the true story? is still unknown.

IMPACT OF CORONAVIRUS ON ITALY

Italy remained one of the worst affected countries by coronavirus both economically and healthwise with 245,338 confirmed cases and 35,092 deaths to date. Late March 2020 was the peak time for SARS-CoV-2 in Italy. The overall death rate was higher than China leading the country in strict lockdown. Now the situation is much better there. Also, the lockdown has been lifted.

CURRENT SCENARIO OF CORONAVIRUS

Now the situation is improving globally after almost seven months of a horrible pandemic affecting 216 countries or territories with 25.1 million confirmed case, out of which 16.5 million people recovered by the grace of God but unfortunately 844,000 people died due to this virus globally.

Especially people with 60+ age are found defenseless to the viral infection. But on the whole, there are more recouped cases than expired. It has been proposed that we will have to learn to live with this virus as it can never vanish and humans are developing immunization to it. Trails for inventing its vaccine are on its way. The lockdown has been lifted from most of the world restoring to normal. The history of mankind has gone through pandemics of this kind at regular intervals. Mankind experienced Spanish influenza in 1920, Cholera in 1820, and Plague in 1720.