Coronavirus: You Need To Know Its Origin, Symptoms & Cases

CORONAVIRUS ITSELF
Coronaviruses are a group of viruses that cause diseases in mammals and birds. ln humans, coronaviruses cause respiratory tract infections that are typically mild, such as the common cold, though rarer forms such as SARS, MERS and COVID-19 can be lethal. 

These viruses were originally transmitted between animals and people. SARS, for instance, was transmitted from civet cats to humans while MERS moved to humans from a type of camel.

The genome size of coronaviruses ranges from approximately 27 to 34 kilobases, the largest  known RNA viruses.

Coronavirus genomes encode a protein called RNA-dependent RNA polymerase (RdRp), which allows the viral genome to be transcribed into new RNA copies using the host cell's machinery. The RdRp is the first protein to be made.

Once the gene encoding the RdRp is translated, translation is stopped by a stop codon. This is known as a nested transcript. 

When the mRNA transcript only encodes one gene, it is monocistronic. 

Coronavirus non-structural proteins provide extra fidelity to replication, because they confer a proofreading function, which is lacking in RNA-dependent RNA polymerase enzymes alone.

In common with the genomes of all other RNA viruses, coronavirus genomes contain cis-acting RNA elements that ensure the specific replication of viral RNA by a virally encoded RNA-dependent RNA polymerase. The embedded cis-acting elements devoted to coronavirus replication constitute a small fraction of the total genome, but this is, as it is presumed, a reflection of the fact that coronaviruses have the largest genomes of all RNA viruses. The boundaries of cis-acting elements essential to replication are fairly well-defined, and an increasingly well-resolved picture of the RNA secondary structures of these regions is emerging. 

However, the understanding of how these cis-acting structures and sequences interact with the viral replicase and host cell components is only in the early stage, and much remains to be done before one understands the precise mechanistic roles of such elements in RNA synthesis.

The genome is replicated and a long polyprotein is formed, where all of the proteins are attached. Coronaviruses have a non-structural protein – a protease – which is able to cleave the polyprotein. This process is a form of genetic economy, allowing the virus to encode the greatest number of genes in a small number of nucleotides.

Proteins that contribute to the overall structure of all coronaviruses are the spike (S), envelope (E), membrane (M), and nucleocapsid (N). In the specific case of the SARS coronavirus, a defined receptor-binding domain on S mediates the attachment of the virus to its cellular receptor, angiotensin-converting enzyme 2 (ACE2). Some coronaviruses (specifically the members of Betacoronavirus subgroup A) also have a shorter spike-like protein called hemagglutinin esterase (HE).

Coronaviruses comprise the sub-family Orthocoronavirinae in the family Coronaviridae, in the order Nidovirales. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry.  

The novel coronavirus, identified by Chinese authorities on January 7 and since named COVID-19, is a new strain that had not been previously identified in humans. Little is known about it, although human-to-human transmission has been confirmed.

ORIGIN

According to reports, Coronaviruses were first identified in the 1960s, but we don't know where they come from. They get their name from their crown-like shape. Sometimes, but not often, a coronavirus can infect both animals and humans.

NOMENCLATURE

The name "coronavirus" is derived from the Latin corona and the Greek κορώνη (korṓnē, "garland, wreath"), meaning crown or halo. The name refers to the characteristic appearance of virions (the infective form of the virus) by electron microscopy, which have a fringe of large, bulbous surface projections creating an image reminiscent of a crown or of a solar corona. This morphology is created by the viral spike (S) peplomers, which are proteins on the surface of the virus that determine host tropism.

INFECTION/SYMPTOMS

Infections range from mild to serious. The virus can turn deadly if it leads to pneumonia, respiratory failure, or septic shock. Those most at risk of death are the elderly and people with weakened immune systems. In human, some of the symptoms include fever, cough and breathing difficulties. Symptoms vary in other species; in chickens, they cause an upper respiratory tract disease, while in cows and pigs they cause diarrhea. There are yet to be vaccines or antiviral drugs to prevent or treat human coronavirus infections.

CASES

According to report, almost everyone gets a coronavirus infection at least once in their life, most likely as a young child. In the United States, coronaviruses are more common in the fall and winter, but anyone can come down with a coronavirus infection at any time.

New cases of infection from the new coronavirus that emerged in the central Chinese city of Wuhan late last year(2019) are being reported daily around the world.

Chinese health officials have reported tens of thousands of cases of COVID‑19 in China, with the virus reportedly spreading from person-to-person in parts of that country. COVID‑19 illnesses, most of them associated with travel from Wuhan, also are being reported in a growing number of international locations, including the United States. 

As of Jan. 29, according to French authorities, "the conditions of the two earliest Paris cases had worsened and the patients were being treated in intensive care, according to French authorities. The patients have been described as a young couple aged 30 and 31 years old, both Chinese citizens from Wuhan who were asymptomatic when they arrived in Paris on January 18 ."

Some person-to-person spread of this virus outside China has been detected. The United States reported the first confirmed instance of person-to-person spread with this virus on January 30, 2020.

It was reported that, "the Centers for Disease Control and Prevention has confirmed multiple cases of novel coronavirus 2019 in people under federal quarantine at JBSA-Lackland in San Antonio. The first was a traveler who returned on a U.S. State Department-chartered flight from Wuhan City, China. The others returned on a State Department flight for passengers from the Diamond Princess cruise ship quarantined in Yokohama, Japan. The individuals will remain isolated at medical facilities until they test negative for the virus and are no longer at risk of spreading it. The CDC has the latest information on the number of people under quarantine who are infected and is updating its national numbers each Monday, Wednesday, and Friday."

According to Aljazeera report(29 - 02 - 2020), more than 2,900 people have died globally from COVID-19, as the illness is officially known, while more than 85,000 infections have been confirmed in dozens of countries, according to the World Health Organization.

The same report has given a comprehensive list of the countries that have so far confirmed cases of the new coronavirus as follows;

Afghanistan - 1

Afghanistan confirmed its first case of coronavirus on February, 24. The minister of public health declared a state of emergency in the western province of Herat which borders Iran.

Algeria - 1

A 61-year-old Italian, who arrived in Algeria on February 17 from Italy, tested positive for the coronavirus.

Australia - 23

Australia has confirmed 23 cases of the virus as of February 28, including several passengers evacuated from the Diamond Princess cruise ship in Japan, according to the Australian government. 

Austria - 5

Austria confirmed its first two cases of coronavirus on February 25, two Italians who live in the province and were probably infected in Italy's Lombardy region, according to authorities. 

Bahrain - 38

The total number of confirmed coronavirus infections in Bahrain rose 38 as of February 29.

Belgium - 1

Belgium said on February 4 that one of nine Belgian citizens repatriated from Wuhan had tested positive for the coronavirus.

Brazil - 1

Brazil's government confirmed on February 26 that a 61-year-old Brazilian man who traveled to Italy this month has Latin America's first confirmed case of the contagious new coronavirus.

The Brazilian man spent two weeks in northern Italy's Lombardy region on a work trip, where he contracted the contagious virus, the health ministry said.

Cambodia - 1

Cambodia confirmed its first case of coronavirus on January 27.

Minister of Health Mam Bunheng said the patient was a 60-year-old Chinese national in the coastal city of Sihanoukville.

Canada - 14

Canada has confirmed 14 cases of the coronavirus as of February 26 - the majority in the province of Ontario and British Columbia.

China - 79,355

As of February 29, a total of 79,251people in mainland China were confirmed as having been infected with the virus, most of them in the central province of Hubei. At least 2,744 people have died, according to the WHO.

The city of Macau has confirmed 10 cases. Hong Kong reported 94 confirmed cases, including two deaths.

Croatia - 5

Five people have tested positive for the virus, including a young man who recently stayed in Italy and his brother. A third case was detected on February 26 in a man who works in the Italian city of Parma.

Denmark - 1 

Denmark has confirmed its first coronavirus infection on February 27in a man who returned from a ski holiday in northern Italy. The man was put in isolation in his own home.

Egypt - 1

Egypt's health ministry reported its first confirmed case of the coronavirus on February 14. It is the first known case in Africa.

Officials said the infected person was a foreign national and on February 19, the World Health Organization said he had been discharged.

Estonia - 1

Estonia has confirmed its first coronavirus case on February 27 in a permanent resident of the country who returned from his native Iran.

Finland - 2

A Chinese tourist who was admitted to hospital for tests was confirmed on January 29 as infected with the coronavirus.

The patient is said to be a 32-year-old woman from Wuhan.

A female Finnish patient who had visited Milan in Italy was diagnosed with the coronavirus on February 26.

France - 57

The number of coronavirus infections in France has leapt to 57 after 19 new cases were confirmed on February 28, Health Minister Olivier Veran says.

An 80-year-old Chinese tourist died in France in mid-February, and a 60-year-old Frenchman died on Wednesday, the first death of a French citizen in France.

Georgia - 2

Georgia reported the first case of coronavirus in the country on February 26 involving a citizen who was travelling from Iran and crossed the border from neighbouring Azerbaijan.

Germany - 57

As of February 29, Germany's cases of coronavirus had risen to 57.

Greece - 3

Greece confirmed its first coronavirus case on February 26, involving a 38-year-old woman in Thessaloniki who returned from Italy's Milan.

On February 27, two new cases were confirmed, one of which concerned a relative of the first patient.

India - 3

On February 3, a third positive case of the coronavirus was reported in India's southern state of Kerala, the country's health ministry said.

All three are students who returned from Wuhan, according to local media.

Iran - 593

Forty-three people have been confirmed dead in Iran because of the coronavirus as of February 29, according tho the health ministry. Meanwhile, the total number of people diagnosed with the virus has risen to 593.

Among prominent people who tested positive for the virus is Masoumeh Ebtekar, vice president of Iran for Women. 

Iraq - 13

Iraq has reported 13 cases as of February 29. The most recent case was a man in Baghdad who had recently traveled to Iran.

Israel - 5

On February 27, Israel reported its third case of coronavirus after a man who returned from Italy tested positive. Two previous patients were evacuees from the Diamond Princess cruise ship in Japan. 

Italy - 888

As of February 29, the number of confirmed cases in Italy stood at 888, mostly centred in the country's north. The death toll is 18.

Japan - 236 and 705

A total of 705 people on the quarantined Diamond Princess cruise ship docked at Yokohama had tested positive for the virus as of February 27. Four elderly people who were on the ship have died. 

Japan does not include the people on board as part of its national tally, in accordance with WHO guidance. The national tally is 236 as of February 29, including five deaths.

Kuwait - 45

On February 28, Kuwait's heath ministry said 45 cases have been confirmed in the country. The two new cases had been in contact with infected people who recently arrived from Iran, health authorities said. 

Lebanon - 7

The first case of coronavirus was confirmed in Lebanon on February 21 after a woman arriving from Iran tested positive. The number of cases increased to seven on February 29.

Lithuania - 1 

Lithuania's government reported the country's first confirmed case of coronavirus in a woman who returned this week from a visit to Italy's northern city of Verona.

Malaysia - 24

Malaysia has a total of 22 confirmed cases as of February 29.

On February 19, the country's health ministry said 15 of the cases had recovered and been discharged from hospital. 

Mexico - 3

Mexico announced its first cases on February 28, with officials reporting that three men who had recently traveled to Italy had been infected.

Nepal - 1

Nepal said on January 24 that a 32-year-old man arriving from Wuhan had tested positive for coronavirus.

The patient, who was initially quarantined, recovered and was discharged. The government said surveillance has been increased at the airport "and suspicious patients entering Nepal are being monitored".

Netherlands - 6

On February 27, a patient in the Netherlands was diagnosed as the country's first case. 

The Dutch National Institute for Public Health said in a statement the patient in the southern city of Tilburg had recently travelled in northern Italy and was being treated in isolation.

As of February 29, six cases were confirmed in the country.

Nigeria - 1

Nigeria confirmed its first case of the virus on February 28, an Italian citizen working in Lagos who had traveled to Milan earlier February. Health officials said the man had been in Nigeria for two days before being isolated, sending authorities scrambling to identify anyone he had had contact with. 

The man was the first confirmed case in sub-Saharan Africa. 

North Macedonia - 1

North Macedonia's health minister said on February 26 that a woman who recently arrived from Italy is the country's first confirmed case.

The woman, who sought medical help early that day, drove to North Macedonia from Italy in a van. All other passengers from the van are undergoing tests, Health Minister Venko Filipce said.

Norway - 6

Norway raised its number of coronavirus cases to six after an employee at Oslo University Hospital's eye clinic was diagnosed with the virus on February 28. 

The employee had recently visited northern Italy and had been to work on Monday and Tuesday. The employee had mild symptoms and was isolated at home, the hospital said. Efforts to track down who he might have gotten in touch with are ongoing. 

Oman - 6

Oman has recorded four confirmed cases of coronavirus in the country as of February 29. All of the cases appeared to be linked to Iran.

Pakistan - 2

Pakistan's Health Minister Zafar Mirza confirmed the first two cases of coronavirus in the country on February 26.

The Philippines - 3

Philippine health officials confirmed a third case of coronavirus on February 5. The country also had the first death from coronavirus outside China, which was announced on February 2.

Qatar - 1 

Qatar reported its first case of coronavirus on February 29, a 36-year-old Qatari man who was recently evacuated from Iran on a government-chartered plane. He had been under quarantine with other evacuees since returning to Qatar, according to the health ministry. 

Romania - 3

Romania reported its first case on February 16 in a man who was in contact with an Italian who visited the country earlier in the month.

Russia - 5

Russia reported two cases of coronavirus on January 31. Both patients - Chinese nationals - have recovered and were discharged from hospital.

In February, Russia repatriated and quarantined eight passengers from the Diamond Princess cruise ship in Japan, three of whom have tested positive.

Singapore - 98

Singapore has a total of 98 cases as of February 29, including dozens of people who have recovered and been discharged from hospital.

South Korea - 3,150

South Korea reported 813 new coronavirus cases on February 29, raising the total number of infections to 3,150, including 17 deaths. The country has the most cases outside of China. 

Spain - 32

Spain has reported 32 confirmed cases in Madrid, Barcelona, Castellon, Tenerife, La Gomera and Mallorca as of February 28.

Sri Lanka - 1

Sri Lanka confirmed its first case of coronavirus on January 27.

The patient was identified as a 43-year-old Chinese woman from Hubei province who had arrived in Sri Lanka as a tourist. She was admitted to the Infectious Diseases Hospital.

Sweden - 11

Four more cases of coronavirus have been diagnosed in Sweden, raising the Scandinavian country's number of cases to 11, health authorities said on February 28. 

Two cases were diagnosed in Stockholm and traced to a woman who had recently visited Iran and was diagnosed the previous day. All three were isolated and in a hospital in the Swedish capital. 

Switzerland - 10

Switzerland reported its first case of coronavirus on February 25 when a 70-year-old man from southern canton of Ticino, which borders Italy, tested positive after a trip to Milan.

On February 29, the country raised the total number of confirmed cases to ten.

Taiwan - 39

Taiwan has 39 confirmed cases as of February 29, including a 61-year-old man with underlying health issues who died from the virus. 

Thailand - 42

Thailand reported a total of 42 cases as of February 29.

Two recent patients confirmed in the country, all of whom were Thai nationals, had returned from vacation in Japan's northern island of Hokkaido and came into contact with a third patient, an eight-year-old boy.

United Arab Emirates - 19

The UAE had a total of 19 confirmed cases as of February 29.

On February 1, the UAE became the first country in the Middle East to confirm cases of the coronavirus.

United Kingdom - 20

The United Kingdom said on February 28 that three additional patients tested positive for the new coronavirus, taking the total tally to 19. The three included one case from Wales, its first.

United States - 62

The US had confirmed 62 cases of the virus as of February 29. 

The cases include those evacuated from the Diamond Princess cruise ship in Japan.

Vietnam - 16

On February 13, the health ministry confirmed the nation's sixteenth case of coronavirus. The authorities have said at least 11 of the cases were in the northern province of Vinh Phuc.

The Son Loi commune in Vinh Phuc was placed under a 14-day quarantine by Vietnamese authorities on February 13.