NOVEL CORONAVIRUS DISEASE 2019 (COVID-19): IN THE EYES OF BIOLOGISTS

“Refuting Misconceptions & Rumors in Scientific light”

Origin: There were a few pneumonia cases in China (December 2019) among a group of people associated with the sea-food and animal market in Wuhan District. The disease gradually spread to near associates and family members. The causative agent was detected to be a previously unknown virus recently named SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) and the disease named COVID-19 (Coronavirus Disease 2019). The origin of the virus is animal while a ‘spillover’ event led to a human being the host of this virus. Two reasons have been postulated i.e. natural selection in the animal host before becoming zoonotic, or natural selection in the human following zoonotic transfer. The reservoir and intermediate hosts of this virus are identified as Bat and Pangolin, respectively. The World Health Organization (WHO) declared the COVID-19 outbreak as a pandemic.

About the Coronavirus: Coronavirus is a large group of viruses having genetic material (RNA) with protein coat (Capsid) and protein spikes. The crown-like structure gave rise to the name ‘Corona’. They are normally responsible for respiratory and sometimes gastrointestinal diseases.

Various other Coronaviruses: Severe disease-causing: SARS-CoV: Severe Acute Respiratory Syndrome Coronavirus (emergence in 2003, China) and MERS: Middle East Respiratory Syndrome Coronavirus (emergence in 2012, Saudi Arabia). MERS-CoV originated in Dromedary Camels (intermediate host) and SERS-CoV originated in Civet cats (intermediate host). In both cases the reservoir host was bats. There are four other Coronaviruses known that causes the common cold in human (mild disease-causing): HCoV-229E (reservoir host: Bats; intermediate host: Dromedary Camels), HCoV-OC43 (reservoir host: Mice; intermediate host: Cattle), HCoV-NL63 (reservoir host: Bats), and HCoV-HKU1 (reservoir host: Mice).

SARS-CoV-2 (Novel Coronavirus): The animal reservoir is predicted to be Bats. It is the seventh coronavirus known to infect humans. The receptor-binding protein in the spike is the most variable part of the genome that uses the Human ACE2 (Angiotensin-converting enzyme 2) receptor to enter into the human cell.

Transmission: Though the exact mechanism is not known, a major route of transmission is through respiratory droplets. Person to Person transmission makes the virus more dangerous.

Symptoms: Ranges from mild to severe – Primary Symptoms (Respiratory): Cough, Breathlessness; Severe: Pneumonia, Death. Loss of ability to smell and taste may be another early symptom of Coronavirus infection according to a recent report.

Incubation Period of the Virus (i.e. infection to development of symptoms): Generally 2-5 days; can go up to 14 days; rarely longer than 14 days, but possible in certain cases.

Mortality: Not exactly known however varies between 3-4%. However for a few countries where community transmission has started the mortality rate can be higher.

Diagnostics: Polymerase Chain Reaction based diagnostics is the only method presently available for detection. Several Hospitals and Institutes have developed the capacity to do the diagnostic test.

Who should get diagnosed? At present, diagnosis is not based on symptoms like fever, cold, sore throat, etc. It is based on 2 criteria: travel to a country of occurrence or incidence of contact with a +ve case /patient of COVID-19.

Treatment: There is no definite treatment as of now. Supportive care is the only option presently available. No drugs/ vaccines are yet approved/ available against COVID-19.

Isolation/ Quarantine Rules:

1. Self-quarantine/ Self-isolation:

• Recommended for asymptomatic individual
• Individual who are having a risk of exposure
• Carefully observe for the onset of symptoms

2. Protective self-separation

• Recommended for the elderly population and children
• A major reason is a non-optimal immunity
• Immuno-compromised individuals
• People having risk factors: Asthma, Hypertension, Diabetes, etc.

3. Social distancing:

• Recommended for all (population measure)
• Avoid crowded places, schools, social gatherings, mass religious programs, rallies, workplaces, amusement centers, shopping malls, movie theatres, etc.

4. Clinical isolation/ Mandatory-quarantine:

• Recommended for the symptomatic individual having a risk of exposure.
• Deals with suspected/ +ve cases.

Prevention: Preventive measure for most of the viruses is vaccines, however, till date there is no such vaccine for COVID-19. Therefore, the main preventive option is to stop the transmission which is challenging due to aerial/ respiratory mode of transmission between humans to humans. The first level of prevention can be the successful identification of infected individual followed by quarantine & treatment. The second level of prevention is to prevent community transfer.

Stages of COVID-19: There are four stages of Transmission as mentioned below:

• Stage 1: High risk of an imported case
• Stage 2: Local Transmission-INDIA Stands here at present
• Stage 3: Community Transmission Epidemic
• Stage 4: Pandemic

Stability of the virus on the surface: Quite stable on inert objects: Aerosol: 3 h or more; Copper: 8 h or more; Cardboard: 24-48 h or more; Plastic: up to 4 days. Real-time situations may vary depending on climatic conditions i.e. temperature and relative humidity.

Are 14 hours of isolation enough to stop the spread?

• Absolutely No.
• It can be a very encouraging step to prevent but certainly not sufficient.
• The concept of 14 h isolation can break the cycle of the virus is baseless and unscientific.

Should all people start using a mask?

• Absolutely No.
• Mask is a way of prevention.
• N95 Mask is not required and is troublesome to breathe. It is also not advisable for a normal individual (asymptomatic) to use such a mask. In case you are comfortable using a mask it implies that you are not wearing it properly.

Does the sipping of Hot water help in killing the virus on the throat?

• Absolutely No.
• Sipping lukewarm water is good to rehydrate the body but not effective to kill the virus.

Does Drinking Alcohol can reduce risk?

• The concept originated since alcohol-based sanitizers are found to be effective in cleaning hands.
• However, Cells in our hands are not the host of the virus. But epithelial cells of the throat (Respiratory / Gastrointestinal tract) are.
• Therefore, the virus stays on the surface of the skin in hands but on your throat, it stays inside the cell.
• This makes the alcohol inaccessible to the virus.
• Moreover, more alcohol consumption can lead to dehydration and other cardiac or related problems.

Does this virus spread through the consumption of Non-veg?

• The virus was of animal origin but the human is its host now.
• Until finding in any animals further, it’s safe.
• Consumption of well-cooked not-veg food should not be a reason to worry.

Does Cow urine serve as a medicine?

• Not known.
• No research/literature suggests this.
• Hence it should be strictly avoided to prevent other complications of bringing in unwanted infections.

Is the virus man-made?

• There is no such scientific basis for this discussion.
• There have always been conspiracy theories in case of large events, but they can be considered as rumors than events.
• Instead, recent research reports suggest that SARS-CoV-2 is not a laboratory construct or a purposefully manipulated virus based on genomic features.

Latest Research:                                 

There have been 900+ publications found on Pubmed with a single key-word COVID-19. That indicated the huge amount of research being carried out in a short period. It also signifies the urgency of reporting scientific information to the world community in case of such a pandemic outbreak. A few important observations are:

1. Probable Pangolin Origin of SARS-CoV-2 Associated with the COVID-19 Outbreak. While exploring potential intermediate hosts of SARS-CoV-2 to control COVID-19 spread they found genomic and evolutionary evidence of the occurrence of a SARS-CoV-2-like CoV (named Pangolin-CoV) in dead Malayan pangolins. The study suggests that pangolin species are a natural reservoir of SARS-CoV-2-like CoVs.

2. Recent reports have brought attention to the possible benefit of chloroquine (CQ), a broadly used anti-malarial drug, in the treatment of patients infected by the novel emerged coronavirus (SARS-CoV-2).

3. Another report proposed that hydroxychloroquine (HCQ), which exhibits an antiviral effect highly similar to that of CQ, could serve as a better therapeutic approach.

A virus essentially stalled the world today and researchers around the world, especially Biotechnologists and Microbiologists, actively working to find a cure. In light of this recent development, it is more essential for the students to choose Biotechnology or Microbiology as a career so that in future the world would have more knowledgeable hands and minds to fight similar outbreaks.