Coronavirus

Coronavirus are a family of viruses responsible for ongoing coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-cov-2).  On 11 March 2020, the World Health Organization (WHO) declared the outbreak a pandemic. First described in detail in the 1960s, the coronavirus gets its name from a distinctive corona or 'crown' of sugary-proteins that project from the envelope surrounding the particle. Encoding the virus's make-up is the longest genome of any RNA-based virus – a single strand of nucleic acid roughly 26,000 to 32,000 bases long.

Coronaviruses are large pleomorphic spherical particles with bulbous surface projections. The diameter of the virus particles is around 120 nm. The envelope of the virus in electron micrographs appears as a distinct pair of electron dense shells.

There are four known genuses in the family, named Alphacoronavirus, Betacoronavirus, Gammacoronavirus, and Deltacoronavirus. The first two only infect mammals, including bats, pigs, cats, and humans. Gammacoronavirus mostly infects birds such as poultry, while Deltacoronavirus can infect both birds and mammals. SARS-CoV-2 is closely related to the original SARS-Cov. It is thought to have a zoonotic origin. Genetic analysis has revealed that the coronavirus genetically clusters with the genus Betacoronavirus, in subgenus Sarbecovirus (lineage B) together with two bat-derived strains.

TRANSMISSION

The virus is thought to spread mainly from person-to-person.

• Between people who are in close contact with one another (within about 6 feet).

• Through respiratory droplets produced when an infected person coughs or sneezes .These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

• People are thought to be most contagious when they are most symptomatic (the sickest).

It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

INCUBATION PERIOD 

The usual incubation period (the time between infection and symptom onset) ranges from one to fourteen days; it is most commonly five days. In one case, it had an incubation period of 27 days.

SYMPTOMS

Symptoms of COVID-19 are non-specific and those infected may either be asymptomatic or develop flu like symptoms . The typical signs and symptoms are dry cough, fever, shortness of breath, fatigue, sputum production, muscle or joints pain, nasal congestion, diarrhea and vomiting. Further development can lead to severe complications like pneumonia, acute respiratory distress syndrome, sepsis, septic shock, kidney failure and death. 

DIAGNOSIS

Infection by the virus can be provisionally diagnosed on the basis of symptoms and CT imaging, though confirmation is ultimately by reverse transcription polymerase chain reaction (rt-PCR) of infected secretions or blood samples.

A person is considered to be at risk of having COVID-19 if they have travelled to an area with ongoing community transmission within the previous 14 days or have had close contact with an infected person. Common key indicators include fever, coughing, and shortness of breath. Other possible indicators include fatigue, myalgia, anorexia, sputum production, and sore throat. Signs of pneumonia may precede confirmation of COVID-19 infection through RT-PCR.

 Characteristic imaging features on radiographs and computed tomography have been described in a limited case series. However, due to overlap with other infections such as adenovirus, imaging without confirmation by PCR is of limited use in identifying COVID-19.

 OUTBREAK 

The virus was first reported in Wuhan, Hubei, China on 17 November 2019. 

The animal source of the latest outbreak has not yet been identified, but the original host is thought to be bats. As of 13 March 2020, more than 142,000 cases have been confirmed worldwide. There is thought to be a substantial under-reporting of cases, particularly of cases with milder symptoms. 

On 31 December 2019, a cluster of pneumonia cases of unknown cause was reported by health authorities in Wuhan, the capital of Hubei province, China, and an investigation was launched in early January 2020. These cases mostly had links to the Huanan Seafood Wholesale Market, which also sold live animal, consequently the virus is thought to have a zoonotic origin. The virus that caused the outbreak is known as SARS-cov-2, a new virus that is closely related to bat coronaviruses pangolin coronaviruses and SARS-cov. It is believed that the virus possibly originated in bats of the Rhinolophus genus. The WHO declared the outbreak to be a Public Health Emergency of International Concern on 30 January.

 During the early stages, the number of cases doubled within a week. In early and mid-January 2020, the virus was spread to other Chinese provinces. By the end of January, China reported nearly 140 new cases in a day, including two people in Beijing and one in Shenzhen. Later the figure increased around 6000 people had already developed symptoms.

In February 2020, the WHO reported that, as new cases reported dropped in China but suddenly increased in Italy, Iran, and South Korea, the number of new cases outside China had exceeded the number of new cases in China for the first time.

 SOCIO ECONOMIC IMPACT

The coronavirus outbreak has been attributed to several instances of supply shortages, stemming from: globally increased usage of equipment to fight the outbreaks, panic buying and disruption to factory and logistic operations. The FDA has issued warnings about shortages to drugs and medical equipment due to increased consumer demand and supplier disruption. Several localities, such as the United States, Italy and Hong Kong, also witnessed panic buying that led to shelves being cleared of grocery essentials such as food, toilet paper and bottled water, inducing supply shortages. The technology industry in particular has been warning about delays to shipments of electronic goods. According to WHO director-general Tedros Adhanom, the demand for personal protection equipment has risen 100-fold and this demand has led to the increase in prices of up to twenty times the normal price and also induced delays on the supply of medical items for four to six months. This has also caused a shortage of personal protective equipment worldwide as well. 

As mainland China is a major economy and a manufacturing hub, the viral outbreak has been seen to pose a major destabilizing threat to the global economy. Some analysts have estimated that the economic fallout of the epidemic on global growth could surpass that of the SARS outbreak. One estimate gives a $300+ billion impact on world's supply chain that could last up to two years. Organization of the Petroleum Exporting Countries reportedly "scrambled" after a steep decline in oil prices due to lower demand from China.  Global Stock markets fell on 24 February due to a significant rise in the number of COVID-19 cases. 

Tourism is one of the worst affected sectors due to a sharp fall in tourists from mainland China and travel advisories warning against travel to parts of Central China, Italy, South Korea and Iran. As a consequence, numerous airlines have cancelled flights due to lower demand, including British Airways, China Eastern and Qantas, while British regional airline Flybe collapsed. Several train stations and ferry ports have also been closed.  A number of events involving large crowds were cancelled by national and regional governments, including annual New Year festivals, with private companies also independently closing their shops and tourist attractions such as Hong Kong Disneyland and Shanghai Disneyland.  Many Lunar New Year events and tourist attractions have been closed to prevent mass gatherings, including the Forbidden City in Beijing and traditional temple fairs. In 24 of China's 31 provinces, municipalities and regions, authorities extended the New Year's holiday to 10 February, instructing most workplaces not to re-open until that date. These regions represented 80% of the country's GDP and 90% of exports. Hong Kong raised its infectious disease response level to the highest and declared an emergency, closing schools until March and cancelling its New Year celebrations. 

Saudi Arabia has temporarily banned foreigners from entering Mecca and Medina, two of Islam's holiest pilgrimage sites, to prevent the spread of coronavirus in the Kingdom.  Another recent, and rapidly accelerating fallout of the disease is the cancellation of major events in sports, the film industry, and other industries, such as music festivals and concerts, technology conferences, fashion shows and sports.

EDUCATIONAL IMPACT

 Millions of children and youth are not attending school because of temporary or indefinite country wide school closures mandated by governments in an attempt to slow the spread of COVID-19. Thirteen countries have shut schools nationwide, affecting students who would normally attend pre-primary to upper-secondary classes. Nine more countries including India have implemented localized school closures to prevent or contain COVID-19. 

Even when school closures are temporary, it carries high social and economic costs. The disruptions they cause affect people across communities, but their impact is more severe for disadvantaged children and their families including interrupted learning, compromised nutrition, childcare problems and consequent economic cost to families who cannot work. In response to school closures caused by COVID-19, UNESCO recommends the use of distance learning programs and open educational applications and platforms that schools and teachers can use to reach learners remotely and limit the disruption of education.

DEATHS

Among those who died from the disease, the time from development of symptoms to death has been shown to be between 6 and 41 days, with a median of 14 days.  As of 14 March 2020, more than 5,800 deaths have been attributed to COVID-19.  According to China's NHC, most of those who died were elderly – about 80% of deaths were in those over 60, and 75% had pre-existing health conditions including cardiovascular diseases and diabetes. 

The first confirmed death was on 9 January 2020 in Wuhan. The first death outside China occurred on 1 February 2020 in the Philippines, and the first death outside Asia was in France. As of 28 February 2020, outside mainland China, more than a dozen deaths have been recorded in each of Iran, South Korea, and Italy. Deaths have also been reported in North America, Australia, San Marino, Spain, Iraq, and the United Kingdom. By 13 March 2020, over 40 countries and territories had reported deaths, on every continent (except Antarctica). 

PREVENTION

Prevention suggestions include good hygiene, such as washing hands when appropriate, avoiding touching the eyes, nose or mouth with unwashed hands, coughing/sneezing into a tissue and putting the tissue directly into a dustbin and (for those who may already have the infection) wearing a surgical mask in public. Social distancing measures are also recommended to prevent transmission

Hand Washing

The Centers for Disease Control and Prevention (CDC) recommends to wash your hands frequently and thoroughly for at least 20 seconds. Use of alcohol-based hand sanitizer with 60% alcohol is advised and not to touch your eyes nose and mouth with unwashed hands.

 Respiratory Hygiene

Health organizations recommended that people cover their mouth and nose with a tissue when coughing or sneezing (which should then be disposed of immediately), or with a sleeve if a tissue is not available. 

Masks are not recommended for most people. Surgical masks are the lowest grade of protection, and are designed mainly to protect others from the wearer. The use of surgical masks by those who may be infected has been recommended as they can limit the volume and travel distance of expiratory droplets dispersed when talking, sneezing, and coughing The WHO has issued instructions on when and how to use masks, including: 

• Cover mouth and nose with mask and make sure there are no gaps between the face and the mask.

• Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water.

• Replace the mask with a new one as soon as it is damp and do not re-use single-use masks.

• Remove the mask using the lace from behind (do not touch the front of a mask); discard immediately and clean hands.

Self-Isolation and Self-Quarantine

Self-isolation at home has been recommended for those diagnosed with COVID-19 and those who suspect they have been infected. Among other instructions, the CDC advises individuals in self-isolation to: 

• Stay at home except to get medical care. Call ahead before visiting a doctor. Not go to work, school, or public areas and avoid using public transportation.

• Wash hands often. Cover coughs and sneezes with a tissue and if sick, wear a facemask around others.

• Stay separated from other people and animals at home; avoid sharing personal items; use a separate bathroom if available.

• Use a household cleaning spray or wipe to clean all frequently-touched surfaces every day.

Social Distancing 

Social distancing includes infection control actions intended to slow the spread of disease by minimizing close contact between individuals. Methods include quarantines, travel restrictions, and closing schools, workplaces, stadiums, theatres, or shopping centre. Individuals may also apply social distancing methods by limiting travel, avoiding crowded areas, and physically distancing themselves from sick individuals. 

Older adults and those with serious chronic conditions face increased risk of serious illness and complications from COVID-19 and have been advised by the US CDC to avoid crowds and stay home as much as possible in areas of community outbreak.

TREATMENT

 There are no specific antiviral medications or vaccine available but development efforts are underway. The symptoms may be relieved by taking regular (over-the-counter) cold medications, drinking fluids, and resting. Depending on the severity, oxygen therapy, intravenous fluids, and breathing support may be required. The use of steroids may worsen outcomes.

Several drugs which were previously approved for treatment of other viral diseases, such as favipiravir, ribavirin, remdesivir and galidesivir, are being investigated against the coronavirus.

VACCINE RESEARCH

There is no vaccine available against COVID-19 by now. A number of private companies and research institutions are trying to develop vaccines.

CONCLUSION

To the date, coronavirus has emerged as an alarming emergency situation all around the world. One must follow all the precautionary measures to protect them from this pandemic infection. Unnecessary travelling should be avoided. Affected individuals must remain in isolation to protect others. These are the ways by which we can fight against this virus.