In December 2019 a novel coronavirus emerged in Wuhan city of China. As of this moment it has infected over 28000 people and killed over 490 individuals globally. This is by far the highest counts a coronavirus pandemic has reached and it is only expected to increase.
Classification Of Coronavirus:
Coronaviruses are the members of the subfamily of Coronavirinae which belongs to the family Coronaviridae under order Nidovirales. The subfamily of Orthocoronavirinae further consists of 4 genera which are alpha, beta, gamma, and delta. Alpha and Beta coronaviruses only infect mammals while the gamma and delta coronaviruses infect birds mainly, but a few infect mammals as well. Alpha and beta coronaviruses usually cause respiratory illness in humans.
- Virus: nCoV-2019
- Genus: Betacoronavirus
- Subfamily: Orthocoronavirinae
- Family: Coronaviridae
- Suborder: Cornidovirineae
- Order: Nidovirales
There are seven strains of coronaviruses which are known to infect humans:
- Human coronavirus 229E (HCoV-229E)
- Human coronavirus OC43 (HCoV-OC43)
- Severe acute respiratory syndrome-related coronavirus (SARS-CoV)
- Human coronavirus NL63 (HCoV-NL63, New Haven coronavirus)
- Human coronavirus HKU1
- The Middle East respiratory syndrome-related coronavirus (MERS-CoV), previously known as novel coronavirus 2012 and HCoV-EMC.
- Novel coronavirus (2019-nCoV), also known as Wuhan coronavirus.
Out of these SARS-CoV and MERS-CoV, cause a severe respiratory syndrome in humans. The other four human coronaviruses (HCoV-NL63, HCoV-229E, HCoV-OC43, and HKU1) cause mild upper respiratory diseases in immunocompetent hosts, although some of them are known to cause severe infections in infants, young children, and elderly individuals.
Viruses in the family Coronaviridae are enveloped, positive-sense, single-stranded RNA viruses. It has the largest viral RNA genome. The virus on its outer surface shows large club-shaped projections which under an electron microscope resemble the solar corona. An envelope is made up of glycoproteins which help in the entry of the virus into the host cells.
The virus has been seen to be transmitted from person to person among close contact (within about 6 feet). This mainly occurs by the route of respiratory droplets formed while an infected person sneezes or coughs.
These droplets can further be inhaled or consumed unintentionally via the oral route by healthy individuals. There have also been reports of spread from an infected person with no symptoms to a close contact.
Coronavirus which affects humans has been found to have a reservoir in mammals.
|Human Coronavirus||Natural Host/ Reservoir|
Currently, 7 of 11 Alpha coronavirus species and 4 of 9 Beta-coronavirus species were identified only in bats. Thus, bats are likely the major natural reservoirs of alpha and beta coronaviruses.
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nCov-2019 is seen to cause respiratory illness in infected individuals. Pneumonia is commonly reported in affected individuals. For confirmed 2019-nCoV infections, reported illnesses have ranged from people with little to no symptoms to people being severely ill and dying.
Symptoms can include:
- Shortness of breath
Reports of chest radiographs showing bilateral infiltrate have been seen in the infected patients. Currently, it is believed that symptoms of 2019-nCoV may appear in as few as 2 days or as long as 14 after exposure.
The WHO has suggested that the case fatality rate is approximately 3%, that is 3 out of 100 infected individuals die.
There has been no definitive treatment found against this virus. At the moment only symptomatic treatment is being provided. It was recently discovered that a protease enzyme in the host cell helps the Beta coronavirus to gain entry into the host cells. (Source: bioRXIV)
Research for using drugs such as protease inhibitors (lopinavir/ritonavir) has begun in late January. Many authorities have found anti-virals used in the treatment of HIV to be effective to some extent.
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Preventive Measures of Coronavirus:
- Wash your hands frequently with an alcohol-based hand rub or soap and water.
- When coughing and sneezing, cover mouth and nose with flexed elbow or tissue (not with hands) and discard tissue immediately into a closed bin. Then clean your hands with alcohol-based hand rub or soap and water.
- Avoid touching eyes, nose and mouth. Touching your eyes, nose or mouth with your contaminated hands, could transfer the virus to you.
- Maintain adequate distance (at least 3 feet) between yourself and other people, particularly those who are sick (fever/cough/difficulty in breathing).
- As a general precaution, practice general hygiene measures when visiting live animal markets, wet markets or animal product markets. Ensure regular hand washing with soap and potable water after touching animals and animal products; avoid touching eyes, nose or mouth with hands; and avoid contact with sick animals or spoiled animal products. Strictly avoid any contact with other animals in the market.
- Avoid the consumption of raw or undercooked animal products.
- If you have a fever, cough and difficulty breathing seek medical care early and inform your medical practitioner, if you’re in close contact with an infected individual or have traveled to China recently.
- If you have mild respiratory symptoms and no relevant history of being in close contact with an infected individual or travel to China recently, be careful and maintain basic respiratory and hand hygiene and if possible, try to stay home until you have recovered.