Coronavirus infection

So far, there have been seven coronaviruses detected in humans. The four most common types of coronaviruses which cause upper respiratory tract infection are:

• 229E (alpha coronavirus)
• NL63 (alpha coronavirus)
• OC43 (beta coronavirus)
• HKU1 (beta coronavirus)

The other two viruses MERS-CoV (beta coronavirus) and SARS-CoV (beta coronavirus) are the more severe forms of coronaviruses which can be fatal. The virus responsible for COVID-19 infection has been named SARS-CoV-2.

Previously known as the 2019 Novel Coronavirus (2019-nCoV), COVID-19 was first identified on 31 December 2019, in Wuhan City, Hubei Province, China.

Since the initial report of cases on 31 December 2019, and as of 12 March 2020, there were over one lakh confirmed cases of COVID-19 infection worldwide. This included 4,638 deaths globally, of which over 3,100 deaths were reported from China.

The symptoms of the disease are known to be:

• Fever
• Chills
• Muscle pain
• Runny nose
• Cough
• Difficulty breathing
• Pneumonia

Severe acute respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). SARS was first reported in Asia in February 2003. According to the WHO, the 2003 outbreak of SARS which started in Southern China and spread to 37 countries ended up making 8,098 people sick and claiming 774 lives.

The virus spread to various countries in North America, South America, Europe, and Asia before it was contained in 2003.

The symptoms of SARS are:

• High fever
• Headache
• Lethargy
• Body ache
• Some patients may develop diarrhoea as well
• After two to seven days, people affected with SARS may develop a dry cough.

Middle East Respiratory Syndrome (MERS), also known as camel flu, is a viral respiratory illness first reported in Saudi Arabia in 2012.

The source of MERS-CoV is said to be an animal from the Arabian Peninsula. Some traces of MERS-CoV were seen in camels and it is believed to be one of the reasons for its spread.

The symptoms of MERS-CoV are:

• Cough
• Fever
• Shortness of breath

This viral infection is life-threatening - three to four out of every 10 people infected with MERS-CoV die.

Human coronaviruses 229E, NL63, OC43, and HKU1 are mostly responsible for causing mild to moderate upper-respiratory tract illnesses like the common cold. They can sometimes cause lower respiratory tract or chest infections, too, like bronchitis or pneumonia. 

The symptoms of coronavirus infection include: 

• Sore throat
• Sneezing and runny nose
• Persistent headache
• Dry cough
• Mild fever
• Lethargy and body pain

Coronavirus can be transmitted through airborne droplets. If a person carrying the Coronavirus sneezes, their nasal mucosa acts as a carrier and transfers it to healthy individuals.

The virus only grows in the hair-like tissues of the respiratory system. The virus results in cell damage and inflammation, this triggers sneezing, obstructs the airway and raises the temperature of the mucosa.

Human Coronaviruses mostly spread through human contact. People can contract the infection by:

• Inhaling the air infected by coughing and sneezing by a carrier of the infection.
• Touching or shaking hands with the carrier.
• Touching an object or surface that has the virus on it.
• In rare cases, the virus can also spread through faecal contamination.

Coronavirus is diagnosed with the help of two different types of tests:

• Molecular tests: Tests like Real-time reverse-transcription polymerase chain reaction (rRT-PCR) are used to detect the viral RNA in the body.\
• Serology tests: Tests like ELISA, or enzyme-linked immunosorbent assay, are done to check the blood for antibodies against the virus.

Though there is no specific treatment available for the human coronavirus, most people suffering from it recover on their own. Symptomatic relief can be given through:

• Antipyretics like paracetamol for fever and body pain.
• Drinking plenty of liquids to prevent dehydration.
• Staying at home to rest, and secluding your belongings from the rest of the family members to prevent the spread of the infection.
• Your doctor may prescribe antibiotics for your sore throat.

In case of severe viral infections, hospitalization may be required to prevent the condition from worsening and also to prevent the spread of infection to others.

Since there are no specific drugs or vaccination for human coronavirus infection, prevention is the only way to safeguard yourself. These small steps can help you avoid the infection:

• Avoid close contact with people who are contaminated with the virus.
• Wash your hands with soap for at least 20 seconds.
• Alcohol-based hand sanitizers may be used if soap and water are not immediately available.
• Do not touch your eyes, nose, or mouth with unwashed hands.
• In the case of the COVID-19, the Indian government has issued advisories to avoid non-essential travel to countries where the infection is widespread.
• In addition to this, there is also an appeal to quarantine yourself for 14 days if you observe any signs of infection in yourself - such as coughing. This will help to prevent the spread of infection to family members and colleagues.