corona virus (COVID-19)
Introduction:-
On
December 31, 2019, China informed the World Health Organization of a cluster of
cases of pneumonia of an unknown cause in Wuhan City in Hubei province. On January
9, 2020, the WHO issued a statement saying Chinese researchers have made
“preliminary determination” of the virus as a novel corona virus.
Since then, more than 6,000 deaths
have been reported due to COVID-19 across the world till March 20, 2020. Cases
have been reported from more than 180 countries, including India. Lockdowns,
curfews, massive airport screenings, quarantines, and social distancing have
become the norm across the globe.
In these critical times, access to
authentic information is of paramount importance. The Hindu has been covering
the pandemic since
the early days with
the highest journalistic standards, ensuring
that science and safety are the primary focus. For the benefit of our
readers, we are now compiling the most relevant parts of our coverage
in the form of an eBook, that we hope will be a handy guide
to good health practices as well as in fighting misinformation.
dksjksukok;jl
D;k gS?
dksjksukok;jl ok;jl dk ,d cMk ifjokj gS ftlesa dqN
xaHkhj lkekU; lnhZ ls ysdj xaHkhj ‘olu flaMªkse ¼ SARS ½ vkSj fefMy
bZLVjsfLijsVjh flaMªkse ¼ MERS ½ tSls xaHkhj jksx gksrs
gS SARS-Cov-21 ,d dksjksukok;l gS tks xaHkhj
‘olu flaMªkse¼
SARS ½
ds dkj.k gksrk gSA dbZ dksjksukok;jl twuksfVd¼ Zoonotic½ gS] ftldk vFkZ ;g gksrk
gS fd ;g jksx tkuokjks ls euq”;ksa esa iszf”kr gksrk gSA tcfd ¼ SARS ½ dksjksukok;jl ,d lkWMuh
i’kq ok;jl ekuk tkrk gS D;kasfd ;g ,d vleku&vfuf’fpr i’kq tyk’k; gS] ’kk;n
pexknM] tks fd vU; tkuojksa ¼flosV dSV~l½ esa QSyrk gS vkSj 2002 essa nf{k.kh
phu ds XokaMksax izkar esa igys laØfer euq”;ksa esa ls ,d gS] dksjksukok;jl
2012 essa lmnh vjc esa balkuks dks MªksesMjh ÅaV ls ikfjr fd;k x;k FkkA bl ckr
ds izek.k gS fd SARS-Cov-21 dks pexknMksa ls Hkh izsf”kr
fd;k x;k gSA
What are corona viruses?
Corona viruses are a
large family of viruses with some causing less severe common cold to more
severe diseases such as severe acute respiratory syndrome (SARS) and Middle
East respiratory syndrome (MERS). The SARS-CoV-21 is a corona virus very
similar to the one that caused SARS. Many corona viruses are zoonotic, meaning
they are transmitted from animals to humans.
While the SARS corona
virus is thought to be an animal virus from an as-yet-uncertain animal
reservoir, perhaps bats, that spread to other animals (civet cats) and first
infected humans in the Guangdong province of southern China in 2002, the MERS corona
virus was passed on from dromedary camels to humans in Saudi Arabia in 2012.
There is evidence that the
SARS-CoV-2 has also been transmitted from bats
 |
1 The Corona
virus Study Group of the International Committee on Taxonomy of Viruses, which
had assessed the novelty of the human pathogen, has named the virus as “Severe
acute respiratory syndrome corona virus 2”,
or “SARS-CoV-2”. The Corona virus
Study Group is responsible for developing the official classification of
viruses and taxa naming of the Coronaviridae
family
Like
other corona viruses, SARS-CoV-2 virus particles are spherical and have
mushroom-shaped proteins called spikes protruding from their surface, giving
the particles a crown-like appearance. The spike binds and fuses to human
cells, allowing the virus to gain entry.
Researchers at the
University of Texas at Austin and the National Institutes of Health, U.S., have
produced a 3D atomic scale map of the protein of the SARS-CoV-2 that binds to
and infects human cells.
Mapping the 3D structure
of the protein — spike (S) glycoprotein — will allow better understanding of
how the virus binds to the human cells. Knowing the structure of the spike
protein will, in turn, allow scientists to develop vaccines and antivirals
against the virus and even better diagnostics.
The spike protein of the novel coronovirus shares 98% sequence
identity with the spike protein of the bat corona virus, the researchers say.
The results were published in the journal Science.
Similar yet different
The researchers also
found that like in the case of the SARS corona virus, the spike protein of the SARS-CoV-2
that causes Corona virus Disease 19 (COVID-19)2 binds to the cellular receptor
called angiotensin-converting enzyme 2 (ACE2), which serves as the entry point
into human cells. But unlike in the case of SARS, the spike protein of the
novel corona virus binds to the cell receptor with much higher affinity — 10-
to 20-fold higher.
|
2 Concerned about the stigma that names of
new diseases can cause to certain people and religion, the WHO came up with the
new guidelines in May 2015. According
to the guidelines, name of a new disease should consist of a combination of
terms. These terms consist of a generic descriptive term based on clinical
symptoms (respiratory), physiological processes (diarrhoea), and anatomical or
pathological references (cardic). It can refer to specific descriptive terms
such as those who are afflicted (infant, juvenile, and maternal), seasonality
(summer, winter) and severity (mild, severe). The name can also include other
factual elements such as the environment (ocean, river), causal pathogen (corona
virus) and the year the new disease is first detected with or without
mentioning the month.
High transmissibility
The much greater binding
affinity to the cell receptor explains the apparent high human-to-human
transmissibility of the virus compared with the SARS corona virus.
“The high affinity of the
2019-nCoV S for human ACE2 may contribute to the apparent ease with which the
2019-nCoV can spread from human-to-human,” the researchers write. “Additional
studies are needed to investigate this possibility.”
Since both the SARS corona
virus and the 2019 novel corona virus share structural similarity and bind to
the same receptor, the researchers tested three monoclonal antibodies specific
to SARS virus for their ability to bind to the novel corona virus. But none of the
three antibodies tested were found to be effective in inhibiting the novel corona
virus from binding to the human receptor ACE2 and prevent or treat the disease.
Spike structure
However, the 3D map of the
S protein will help researchers design new antiviral to stop the virus from
binding and infecting human cells. “Knowing the atomic-level structure of the
2019-nCoV spike will allow for additional protein engineering efforts that
could improve Antigenicity and protein expression for vaccine development,” the
researchers write.
The researchers were able
to determine the structure of the spike protein as the Chinese researchers
shared the whole genome sequence data in the global database.
Genome sequencing
When the entire genome is
sequenced it helps researchers understand the arrangement of the four chemical
entities or bases that make up the
DNA or RNA. The differences in the arrangement of the bases make organisms
different from one another. Sequencing the genome of SARS-CoV-2 will help us
understand where the virus came from and how it spread. For instance, by
sequencing the genome of the virus isolated from an Indian patient, it will
become possible to know if the virus had come from China or any other country
In India, the Pune-based
National Institute of Virology (NIV)3 has sequenced the SARS-CoV-2
genome collected from two patients in Kerala.
|
3 NIV is the only lab in India which has a
bio-safety level-4 (BSL-4) facility to culture pathogenic, novel viruses, study
the origin of such viruses and provide a comprehensive characterization of them
by sequencing the entire viral genome.
Understanding the disease
The World Health Organization
has declared COVID-19 to be a pandemic4. The symptoms of COVID-19
appear within two to 14 days after
exposure and include fever, cough, a runny nose and difficulty in breathing.
How does the disease spread?
It primarily spreads through
the respiratory droplets
of infected people. If a person touches a surface or
object that has been infected by the virus and then touches his own mouth,
nose, or eyes, he may get infected.
Who is affected?
While people
of all ages can be affected by the disease,
people aged 80 and
above are at the highest
risk of dying due to COVID-19, according to case records analyzed
by the Disease Control and Prevention Centers in China and South Korea. Victims
of the virus with pre-existing medical conditions such as cardiovascular
disease and diabetes have a higher fatality rate than others. Also the rate of
fatalities was relatively higher for retirees.
|
A ‘Pandemic’ generally refers to an epidemic that has spread on a more global scale, affecting large numbers of people. Exactly when enough places have enough infections to declare one isn’t a black-and-white decision. But generally, the WHO is looking for sustained outbreaks on different continents. An ‘Epidemic’ is a large outbreak, one that spreads among a population or region. An ‘Outbreak’ is a sudden rise in cases of a disease in a particular place.
 |
Data visualisations
by Vignesh Radhakrishnan and Sumant Sen
What are the symptoms?
The guidelines from the
Union Health Ministry for early recognition of
COVID-19 patients are those who come in with Severe Acute Respiratory Infection
(SARI) who also have a history of foreign travel or close contact with another COVID-19
patient.
As per the guidelines,
“COVID–19 may present with mild, moderate, or severe illness; the latter
includes severe pneumonia, ARDS [Acute Respiratory Distress Syndrome], sepsis
and septic shock.”
How can it be detected?
The virus can be detected using a RT-PCR
test6. An RT-PCR
or reverse transcription
polymerase chain reaction test is DNA-based and can quickly tell if someone harbors
the virus. In India, the government facilities to test for the virus include 52
labs belonging to the Viral Research and Diagnostic Laboratories network of the
Indian Council of Medical Research (ICMR), 10 labs under the National Centre
for Disease Control (NCDC), and the NIV.
What is the treatment?
There is no current
evidence from randomized controlled trial to recommend any specific treatment for suspected or confirmed COVID- 19 patients. No specific anti-virals
are recommended for treatment of those suffering from respiratory ailment due
to lack of adequate evidence from medical literature.
|
4
Guidelines on
Clinical Management of COVID – 19
5
The National Human
Genome Research Institute on PCR:
“Sometimes called "molecular photocopying," the
polymerase chain reaction (PCR) is a fast and inexpensive technique used to
"amplify" - copy - small segments of DNA. Because significant amounts
of a sample of DNA are necessary for molecular and genetic analyses, studies of
isolated pieces of DNA are nearly impossible without PCR amplification.
Often heralded as one of the most important scientific advances
in molecular biology, PCR revolutionized the study of DNA to such an extent
that its creator, Kary B. Mullis, was awarded the Nobel Prize for Chemistry in
1993.”
In India, the Union
Health Ministry guidelines has recommended use of anti-HIV drug combinations
Lopinavir and Ritonavir on a case-to- case basis depending upon the severity of
the condition of a person having corona virus infection.
The
Ministry recommended Lopinavir-Ritonavir for high-risk groups: patients aged
above 60, suffering from diabetes mellitus, renal failure, chronic lung disease
and are immuno-compromised.
However, the use of
Lopinavir-Ritonavir in PEP regimens for HIV is also associated with significant adverse events which many times leads
to discontinuation of therapy.
The guidelines advise the
treating doctors to closely monitor patients with severe acute respiratory
infection for signs of clinical deterioration,
such as rapidly progressive respiratory failure and sepsis, and apply supportive care
interventions immediately.
“Application of timely,
effective, and safe supportive therapies is the cornerstone of therapy for
patients that develop severe manifestations of COVID-19,” it said.
Can a vaccine be developed for COVID-19?
According to Raman. R. Gangakhedkar, head of the Epidemiology and Communicable Diseases-I (ECD-I),
Division of ICMR, there are two ways of going for vaccine preparation — either
you look at the sequences of the gene which then may lead to development of
antibodies, or you actually have the strain and then you try to develop a
vaccine which is always an easier option. He said Indian scientists have managed
to successfully isolate
the COVID-19 virus and about 11
isolates are available which is a prime requisite for doing any kind of research
related to viruses and developing the vaccine.
Internationally, several
institutes and pharmaceutical companies are in various stages of developing the vaccine with some set to go on clinical trials soon.
|
6 From a report in The
Guardian dated March 19, 2020: “The Oxford [University]
vaccine, known as ChAdOx1, is one of five frontrunner vaccines in development
around the world. The US biotech Moderna gave its first vaccine shot to a person in Seattle earlier
this week. Another
US firm, Inovio,
will soon start
trials on its own
Protecting yourself against COVID-19
Guidelines
by the World Health Organization specify that one of the ways to reduce the
risk of infection is by regularly and thoroughly cleaning one’s hands with an
alcohol-based hand rub or washing them with soap and water. Regular washing
becomes important as the virus tends to be viable from hours to more than a day
on different surfaces that are regularly touched with hands.
Washing with soap
The grime on our hands
contains innumerable viruses and bacteria. Washing with water without using
soap helps reduce the amount of microbes but does not remove most of the virus
and bacteria completely. Using soap, therefore, becomes far more effective in removing
microbes.
Viruses such as corona
virus, influenza-causing viruses, Ebola, Zika have their genetic material
encased in a layer of fat called the lipid envelope8. Soap molecules
are pin-shaped with a head that is water- loving (hydrophilic) and a tail that
is oil-loving (oleophilic). Being oleophilic, the tail portion of the molecule
tends to have an affinity for and ‘competes’ with the lipids in the virus envelope.
Since the chemical bonds holding the virus together are not very strong, the long oleophilic tail gets inserted into the envelope
and tends to have a ‘crowbar’ effect that breaks the lipid envelope of
the virus. The tail also competes with the bond that binds the RNA and the
lipid envelop thus dissolving the virus into its components which are then
removed by water.
|
corona virus vaccine, which requires a special device to
administer through the skin. In Germany, CureVac is working on a vaccine, while
others are in development in China.”
7
Do
all viruses have the lipid layer? No, certain viruses do not have the lipid
envelope and are called the non- enveloped viruses. Rotavirus
which causes severe
diarrhoea, poliovirus, adenovirus that cause pneumonia and even human papillomavirus (HPV) do not contain the lipid envelope.
Alcohol-based hand sanitisers
Like soap, the alcohol
present in hand sanitizers dissolve the lipid envelope, thus inactivating the virus. In addition, the alcohol also tends
to change the shape or denature the mushroom-shaped protein structures that
stick out of the lipid envelope. The mushroom-shaped protein structures help
the virus to bind to special structures found on human cells and enter the
cells. To be effective, the sanitizers should contain at least 60% alcohol.
Unlike soap lather, the
alcohol does not come in contact with all parts of the hand. So care needs to
be taken to use sufficient sanitizer to increase the coverage. Unlike water,
alcohol run does not remove the dead viruses from the hand. While a sanitiser
can quickly reduce the number of microbes, it does not get rid of all types of germs, and is “not as effective when hands are visibly
dirty or greasy”.
Using a mask
Medical masks help
prevent the spread of corona virus infection. If worn properly, masks may be effective
in preventing transmission of corona virus. An article published in the Journal
of the American Medical Association (JAMA) says there is no evidence to suggest
that masks worn by healthy individuals can help prevent infection.
But a 2010 study says:
“Mask wearing was associated with reduced secondary transmission and should be
encouraged during outbreak situations.”
Even the World Health
Organization says wearing a medical mask is “one of the prevention measures to
limit spread of certain respiratory diseases, including novel corona virus
(SARS-CoV-2), in affected areas”.
Transmission through
droplets from coughing and sneezing is one of the major routes of virus spread.
When worn correctly, a mask can reduce the risk of inhaling droplets containing
the virus.
With many
studies showing that
people infected with
novel corona virus transmit the virus even before symptoms
show up, it may be prudent to wear a mask especially when the virus
is spreading in the community.
In
a country like India, maintaining at least one metre distance can be a challenge, especially when there
is no way of knowing
who is infected till such time the person starts showing visible symptoms.
Social distancing
The WHO says that you
should maintain at least 1 metre (3 feet) distance between yourself and anyone
who is coughing or sneezing.
This is because when
someone coughs or sneezes they spray small liquid droplets from their nose or
mouth which may contain virus. “If you are too close, you can breathe in the
droplets, including the COVID-19 virus if the person coughing has the disease,”
says the WHO.
Avoid touching eyes, nose and mouth
Hands can pick up viruses as they come in contact
with many surfaces. It can then transfer the virus
to your eyes, nose or mouth. From there, the virus can enter your body and can
make you sick.
Practise respiratory hygiene
Cover your mouth and nose
with your bent elbow or tissue when you cough or sneeze. Then dispose of the
used tissue immediately.
Some common queries answered.
Ø Are the re differences between symptoms caused by the flu and COVID-19?
Cough and cold could mean
an allergy. A fever with cough and cold is
a symptom of the flu. When you have fever with a cough which is complicated by breathlessness, it is a symptom of Corona
virus infection and you must call your doctor to rule it out.
Ø How effective are thermal scanners in detecting people infected with the new corona virus?
Thermal scanners
are effective in detecting people
who have developed a fever (i.e. have a higher
than normal body temperature) because of infection with the new corona virus.
However, they cannot detect people who are infected but are not yet sick with fever.
This is because it takes between 2 and 10 days before people who are
infected become sick and develop a fever.
Ø Can a person exposed to Corona virus transmit it to others if he/she uses a swimming pool?
Highly unlikely. The Corona
virus is a droplet infection. It has to be inhaled to cause the disease.
Chlorination of swimming pools to recommended levels can certainly inactivate
any virus, including COVID-19.
Ø Should people avoid eating meat-based food to prevent transmission?
It is a respiratory virus
and not a food-borne one. Corona virus has nothing to do with food or pet
animals or eating chicken and mutton. People can eat whatever they want and how
much ever they want.
Ø Is there a link between a person’s immunity and COVID-19 transmission?
Coronovirus is one of the weakest
family of viruses.
The deaths caused so far or people affected could
have been ones with less immunity like children or the elderly. Sometimes, the virus
enters a person’s lungs and causes pneumonia. People with vulnerable immunity
like the elderly succumb to this. For young people with good immunity, the
effects of the virus may not be too strong but if you are someone with comorbid
conditions like diabetes or cardiac disease, or if you are on immunosuppressive
drugs, then the risk of infection is severe.
Ø Are there any home remedies to treat COVID-19?
Home remedies and
treatment other than allopathy is not proven science. The best thing is precaution only. You must keep away from a patient who coughs and sneezes. If you are coughing, you need to cover
your face with a mask and not spread the droplets around. COVID-19 spreads
through droplets.
Ø Are antibiotics effective in preventing and treating the new corona virus?
No, antibiotics do not
work against viruses, only bacteria. The new corona virus (2019-nCoV) is a
virus and, therefore, antibiotics should not be used as a means of prevention
or treatment.
However, if you are
hospitalized for the 2019-nCoV, you may receive antibiotics because bacterial
co-infection is possible.
Ø Do vaccines against pneumonia protect you against the new corona virus?
No. Vaccines against
pneumonia, such as pneumococcal vaccine and Haemophilus influenza type B (Hib) vaccine,
do not provide protection
against the new corona virus. The virus is so new and different that it needs
its own vaccine.
Although these vaccines
are not effective against 2019-nCoV, vaccination against respiratory illnesses
is highly recommended to protect your health.
Ø Myths around COVID-19
There have been several
myths around the disease, like consuming more
garlic, curry leaves
or cow’s urine would treat or protect
one from the disease.
The World Health Organization has busted such misleading claims.
On garlic, WHO said it is a healthy
food that may have some antimicrobial
properties but there is no evidence that it has prevented people from
contracting the 2019 nCoV.
Ø Here are some other myths and the WHO’s response to them:
Myth: “COVID-19 virus cannot be transmitted in areas with hot and humid
climates”
From
the evidence so far, the COVID-19 virus can be transmitted in ALL AREAS,
including areas with hot and humid weather.
Regardless of
climate, adopt protective measures if you live in, or travel
to an area reporting COVID-19. The best way to protect
yourself against COVID- 19 is by frequently cleaning your hands.
By doing this you eliminate viruses that may be on your hands and avoid
infection that could occur by then
touching your eyes, mouth, and nose.
Myth: The new corona
virus can be transmitted through mosquito bites.
To
date there has been no information nor evidence to suggest that the new corona
virus could be transmitted by mosquitoes. The new corona virus is a respiratory
virus which spreads primarily through droplets generated when an infected
person coughs or sneezes, or through droplets of saliva or discharge from the
nose. To protect yourself, clean your hands frequently with an alcohol-based
hand rub or wash them with soap and water. Also, avoid close contact with
anyone who is coughing and sneezing.
National and State helplines
(Please note that these numbers
are subject to change.)
The
new national helpline numbers are 1075 / 1800-112-545 /011-23978046
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State / UT
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State Helpline No.
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Andhra
Pradesh
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0866-2410978
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Arunachal
Pradesh
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9436055743
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Assam
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6913347770
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Bihar
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104
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Chhattisgarh
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077122-35091
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Goa
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104
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Gujarat
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104
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Haryana
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8558893911
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Himachal
Pradesh
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104
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Jharkhand
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104
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Karnataka
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104
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Kerala
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0471-2552056
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Madhya
Pradesh
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0755-2527177
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Maharashtra
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020-26127394
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Manipur
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3852411668
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Meghalaya
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108
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Mizoram
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102
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Nagaland
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7005539653
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Odisha
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9439994859
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Punjab
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104
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Rajasthan
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0141-2225624
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Sikkim
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104
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Tamil
Nadu
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044-29510500
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Telangana
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104
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Tripura
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0381-2315879
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Uttarakhand
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104
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Uttar
Pradesh
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18001805145
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West Bengal
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3323412600
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Andaman and
Nicobar Islands
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03192-232102
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Chandigarh
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9779558282
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Dadra
and Nagar Haveli and Daman & Diu
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104
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Delhi
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011-22307145
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Jammu
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01912520982
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Kashmir
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01942440283
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Ladakh
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01982256462
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Lakshadweep
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104
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Puducherry
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104
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corona virus (COVID-19)
Introduction:-
On December 31, 2019, China informed the World
Health Organization of a cluster of cases of pneumonia of an unknown cause in
Wuhan City in Hubei province. On January 9, 2020, the WHO issued a statement
saying Chinese researchers have made “preliminary determination” of the virus
as a novel corona virus.
Since then,
more than 6,000 deaths have been reported due to COVID-19 across the world till
March 20, 2020. Cases have been reported from more than 180 countries,
including India. Lockdowns, curfews, massive airport screenings, quarantines,
and social distancing have become the norm across the globe.
In these
critical times, access to authentic information is of paramount importance. The Hindu has been covering
the pandemic since
the early days with
the highest journalistic standards, ensuring
that science and safety are the primary focus. For the benefit of our
readers, we are now compiling the most relevant parts of our coverage
in the form of an eBook, that we hope will be a handy guide
to good health practices as well as in fighting misinformation.
dksjksukok;jl D;k
gS?
dksjksukok;jl ok;jl dk ,d cMk
ifjokj gS ftlesa dqN xaHkhj lkekU; lnhZ ls ysdj xaHkhj ‘olu flaMªkse ¼ SARS ½
vkSj fefMy bZLVjsfLijsVjh flaMªkse ¼ MERS ½ tSls
xaHkhj jksx gksrs gS SARS-Cov-21 ,d
dksjksukok;l gS tks xaHkhj ‘olu flaMªkse¼ SARS ½ ds
dkj.k gksrk gSA dbZ dksjksukok;jl twuksfVd¼ Zoonotic½ gS]
ftldk vFkZ ;g gksrk gS fd ;g jksx tkuokjks ls euq”;ksa esa iszf”kr gksrk gSA
tcfd ¼ SARS ½ dksjksukok;jl ,d lkWMuh i’kq ok;jl ekuk tkrk gS D;kasfd
;g ,d vleku&vfuf’fpr i’kq tyk’k; gS]
’kk;n pexknM] tks fd vU; tkuojksa ¼flosV dSV~l½ esa QSyrk gS vkSj 2002 essa
nf{k.kh phu ds XokaMksax izkar esa igys laØfer euq”;ksa esa ls ,d gS]
dksjksukok;jl 2012 essa lmnh vjc esa balkuks dks MªksesMjh ÅaV ls ikfjr fd;k
x;k FkkA bl ckr ds izek.k gS fd SARS-Cov-21 dks pexknMksa ls Hkh izsf”kr fd;k x;k gSA
What are corona viruses?
Corona
viruses are a large family of viruses with
some causing less severe common cold to more severe diseases such as severe
acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS).
The SARS-CoV-21 is a corona virus very similar to the one that caused SARS. Many
corona viruses are zoonotic, meaning they are transmitted from animals to
humans.
While
the SARS corona virus is thought to be an animal virus from an as-yet-uncertain
animal reservoir, perhaps bats, that spread to other animals (civet cats) and
first infected humans in the Guangdong province of southern China in 2002, the MERS
corona virus was passed on from dromedary camels to humans in Saudi Arabia in 2012.
There
is evidence that the SARS-CoV-2 has also been transmitted from bats
1 The Corona virus Study Group of the International Committee on
Taxonomy of Viruses, which had assessed the novelty of the human pathogen, has
named the virus as “Severe acute respiratory syndrome corona virus 2”, or “SARS-CoV-2”. The Corona virus Study Group is
responsible for developing the official classification of viruses and taxa
naming of the Coronaviridae family
Like other corona viruses, SARS-CoV-2 virus particles
are spherical and have mushroom-shaped proteins called spikes protruding from
their surface, giving the particles a crown-like appearance. The spike binds
and fuses to human cells, allowing the virus to gain entry.
Researchers
at the University of Texas at Austin and the National Institutes of Health,
U.S., have produced a 3D atomic scale map of the protein of the SARS-CoV-2 that
binds to and infects human cells.
Mapping
the 3D structure of the protein — spike (S) glycoprotein — will allow better
understanding of how the virus binds to the human cells. Knowing the structure
of the spike protein will, in turn, allow scientists to develop vaccines and
antivirals against the virus and even better diagnostics.
The
spike protein of the novel coronovirus shares 98% sequence identity with the
spike protein of the bat corona virus, the researchers say. The results were published
in the journal Science.Similar yet
different
The
researchers also found that like in the case of the SARS corona virus, the
spike protein of the SARS-CoV-2 that causes Corona virus Disease 19 (COVID-19)2
binds to the cellular receptor called angiotensin-converting enzyme 2 (ACE2),
which serves as the entry point into human cells. But unlike in the case of SARS,
the spike protein of the novel corona virus binds to the cell receptor with
much higher affinity — 10- to 20-fold higher.
2
Concerned about the stigma that names of
new diseases can cause to certain people and religion, the WHO came up with the
new guidelines in May 2015. According
to the guidelines, name of a new disease should consist of a combination of
terms. These terms consist of a generic descriptive term based on clinical
symptoms (respiratory), physiological processes (diarrhoea), and anatomical or
pathological references (cardic). It can refer to specific descriptive terms
such as those who are afflicted (infant, juvenile, and maternal), seasonality
(summer, winter) and severity (mild, severe). The name can also include other
factual elements such as the environment (ocean, river), causal pathogen (corona
virus) and the year the new disease is first detected with or without
mentioning the month.
High transmissibility
The
much greater binding affinity to the cell receptor explains the apparent high
human-to-human transmissibility of the virus compared with the SARS corona
virus.
“The
high affinity of the 2019-nCoV S for human ACE2 may contribute to the apparent
ease with which the 2019-nCoV can spread from human-to-human,” the researchers
write. “Additional studies are needed to investigate this possibility.”
Since
both the SARS corona virus and the 2019 novel corona virus share structural
similarity and bind to the same receptor, the researchers tested three
monoclonal antibodies specific to SARS virus for their ability to bind to the novel
corona virus. But none of the three antibodies tested were found to be
effective in inhibiting the novel corona virus from binding to the human
receptor ACE2 and prevent or treat the disease.
Spike structure
However, the 3D map of the
S protein will help researchers design new antiviral to stop the virus from
binding and infecting human cells. “Knowing the atomic-level structure of the
2019-nCoV spike will allow for additional protein engineering efforts that
could improve Antigenicity and protein expression for vaccine development,” the
researchers write.
The researchers were able
to determine the structure of the spike protein as the Chinese researchers
shared the whole genome sequence data in the global database.
Genome sequencing
When the entire genome is
sequenced it helps researchers understand the arrangement of the four chemical
entities or bases that make up the
DNA or RNA. The differences in the arrangement of the bases make organisms
different from one another. Sequencing the genome of SARS-CoV-2 will help us
understand where the virus came from and how it spread. For instance, by
sequencing the genome of the virus isolated from an Indian patient, it will
become possible to know if the virus had come from China or any other country
In India, the Pune-based
National Institute of Virology (NIV)3 has sequenced the SARS-CoV-2
genome collected from two patients in Kerala.
 |
3
NIV is the only lab in India which has a
bio-safety level-4 (BSL-4) facility to culture pathogenic, novel viruses, study
the origin of such viruses and provide a comprehensive characterization of them
by sequencing the entire viral genome.
Understanding the disease
The World Health Organization
has declared COVID-19 to be a pandemic4. The symptoms of COVID-19
appear within two to 14 days after
exposure and include fever, cough, a runny nose and difficulty in breathing.
How does the disease spread?
It primarily spreads through
the respiratory droplets
of infected people. If a person touches a surface or
object that has been infected by the virus and then touches his own mouth,
nose, or eyes, he may get infected.
Who is affected?
While people
of all ages can be affected by the disease,
people aged 80 and
above are at the highest
risk of dying due to COVID-19, according to case records analyzed
by the Disease Control and Prevention Centers in China and South Korea. Victims
of the virus with pre-existing medical conditions such as cardiovascular
disease and diabetes have a higher fatality rate than others. Also the rate of
fatalities was relatively higher for retirees.
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A ‘Pandemic’ generally refers to an epidemic that has spread on a more global scale, affecting large numbers of people. Exactly when enough places have enough infections to declare one isn’t a black-and-white decision. But generally, the WHO is looking for sustained outbreaks on different continents. An ‘Epidemic’ is a large outbreak, one that spreads among a population or region. An ‘Outbreak’ is a sudden rise in cases of a disease in a particular place.
What are the symptoms?
The guidelines from the
Union Health Ministry for early recognition of
COVID-19 patients are those who come in with Severe Acute Respiratory Infection
(SARI) who also have a history of foreign travel or close contact with another COVID-19
patient.
As per the guidelines,
“COVID–19 may present with mild, moderate, or severe illness; the latter
includes severe pneumonia, ARDS [Acute Respiratory Distress Syndrome], sepsis
and septic shock.”
How can it be detected?
The virus can be detected using a RT-PCR
test6. An RT-PCR
or reverse transcription
polymerase chain reaction test is DNA-based and can quickly tell if someone harbors
the virus. In India, the government facilities to test for the virus include 52
labs belonging to the Viral Research and Diagnostic Laboratories network of the
Indian Council of Medical Research (ICMR), 10 labs under the National Centre
for Disease Control (NCDC), and the NIV.
What is the treatment?
There is no current
evidence from randomized controlled trial to recommend any specific treatment for suspected or confirmed COVID- 19 patients. No specific anti-virals
are recommended for treatment of those suffering from respiratory ailment due
to lack of adequate evidence from medical literature.
|
4
Guidelines on Clinical Management of COVID – 19
5 The National Human
Genome Research Institute on PCR:
“Sometimes called "molecular photocopying," the
polymerase chain reaction (PCR) is a fast and inexpensive technique used to
"amplify" - copy - small segments of DNA. Because significant amounts
of a sample of DNA are necessary for molecular and genetic analyses, studies of
isolated pieces of DNA are nearly impossible without PCR amplification.
Often heralded as one of the most important scientific advances
in molecular biology, PCR revolutionized the study of DNA to such an extent
that its creator, Kary B. Mullis, was awarded the Nobel Prize for Chemistry in
1993.”
In India, the Union
Health Ministry guidelines has recommended use of anti-HIV drug combinations
Lopinavir and Ritonavir on a case-to- case basis depending upon the severity of
the condition of a person having corona virus infection.
The
Ministry recommended Lopinavir-Ritonavir for high-risk groups: patients aged
above 60, suffering from diabetes mellitus, renal failure, chronic lung disease
and are immuno-compromised.
However, the use of
Lopinavir-Ritonavir in PEP regimens for HIV is also associated with significant adverse events which many times leads
to discontinuation of therapy.
The guidelines advise the
treating doctors to closely monitor patients with severe acute respiratory
infection for signs of clinical deterioration,
such as rapidly progressive respiratory failure and sepsis, and apply supportive care
interventions immediately.
“Application of timely,
effective, and safe supportive therapies is the cornerstone of therapy for
patients that develop severe manifestations of COVID-19,” it said.
Can a vaccine be developed for COVID-19?
According to Raman. R. Gangakhedkar, head of the Epidemiology and Communicable Diseases-I (ECD-I),
Division of ICMR, there are two ways of going for vaccine preparation — either
you look at the sequences of the gene which then may lead to development of
antibodies, or you actually have the strain and then you try to develop a
vaccine which is always an easier option. He said Indian scientists have managed
to successfully isolate
the COVID-19 virus and about 11
isolates are available which is a prime requisite for doing any kind of research
related to viruses and developing the vaccine.
Internationally, several
institutes and pharmaceutical companies are in various stages of developing the vaccine with some set to go on clinical trials soon.
|
6 From
a report in The Guardian dated March 19,
2020: “The Oxford [University] vaccine, known as ChAdOx1, is one of five
frontrunner vaccines in development around the world. The US biotech Moderna
gave its first vaccine shot to a person
in Seattle earlier
this week. Another
US firm, Inovio,
will soon start
trials on its own
Protecting yourself against COVID-19
Guidelines
by the World Health Organization specify that one of the ways to reduce the
risk of infection is by regularly and thoroughly cleaning one’s hands with an
alcohol-based hand rub or washing them with soap and water. Regular washing
becomes important as the virus tends to be viable from hours to more than a day
on different surfaces that are regularly touched with hands.
Washing with soap
The grime on our hands
contains innumerable viruses and bacteria. Washing with water without using
soap helps reduce the amount of microbes but does not remove most of the virus
and bacteria completely. Using soap, therefore, becomes far more effective in removing
microbes.
Viruses such as corona
virus, influenza-causing viruses, Ebola, Zika have their genetic material
encased in a layer of fat called the lipid envelope8. Soap molecules
are pin-shaped with a head that is water- loving (hydrophilic) and a tail that
is oil-loving (oleophilic). Being oleophilic, the tail portion of the molecule
tends to have an affinity for and ‘competes’ with the lipids in the virus envelope.
Since the chemical bonds holding the virus together are not very strong, the long oleophilic tail gets inserted into the envelope
and tends to have a ‘crowbar’ effect that breaks the lipid envelope of
the virus. The tail also competes with the bond that binds the RNA and the
lipid envelop thus dissolving the virus into its components which are then
removed by water.
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corona virus vaccine, which requires a special device to
administer through the skin. In Germany, CureVac is working on a vaccine, while
others are in development in China.”
7
Do all viruses have the lipid layer? No,
certain viruses do not have the lipid envelope and are called the non-
enveloped viruses. Rotavirus
which causes severe
diarrhoea, poliovirus, adenovirus that cause pneumonia and even human papillomavirus (HPV) do not contain the lipid envelope.
Alcohol-based hand sanitisers
Like soap, the alcohol
present in hand sanitizers dissolve the lipid envelope, thus inactivating the virus. In addition, the alcohol also tends
to change the shape or denature the mushroom-shaped protein structures that
stick out of the lipid envelope. The mushroom-shaped protein structures help
the virus to bind to special structures found on human cells and enter the
cells. To be effective, the sanitizers should contain at least 60% alcohol.
Unlike soap lather, the
alcohol does not come in contact with all parts of the hand. So care needs to
be taken to use sufficient sanitizer to increase the coverage. Unlike water,
alcohol run does not remove the dead viruses from the hand. While a sanitiser
can quickly reduce the number of microbes, it does not get rid of all types of germs, and is “not as effective when hands are visibly
dirty or greasy”.
Using a mask
Medical masks help
prevent the spread of corona virus infection. If worn properly, masks may be effective
in preventing transmission of corona virus. An article published in the Journal
of the American Medical Association (JAMA) says there is no evidence to suggest
that masks worn by healthy individuals can help prevent infection.
But a 2010 study says:
“Mask wearing was associated with reduced secondary transmission and should be
encouraged during outbreak situations.”
Even the World Health
Organization says wearing a medical mask is “one of the prevention measures to
limit spread of certain respiratory diseases, including novel corona virus
(SARS-CoV-2), in affected areas”.
Transmission through
droplets from coughing and sneezing is one of the major routes of virus spread.
When worn correctly, a mask can reduce the risk of inhaling droplets containing
the virus.
With many
studies showing that
people infected with
novel corona virus transmit the virus even before symptoms
show up, it may be prudent to wear a mask especially when the virus
is spreading in the community.
In
a country like India, maintaining at least one metre distance can be a challenge, especially when there
is no way of knowing
who is infected till such time the person starts showing visible symptoms.
Social distancing
The WHO says that you
should maintain at least 1 metre (3 feet) distance between yourself and anyone
who is coughing or sneezing.
This is because when
someone coughs or sneezes they spray small liquid droplets from their nose or
mouth which may contain virus. “If you are too close, you can breathe in the
droplets, including the COVID-19 virus if the person coughing has the disease,”
says the WHO.
Avoid touching eyes, nose and mouth
Hands can pick up viruses as they come in contact
with many surfaces. It can then transfer the virus
to your eyes, nose or mouth. From there, the virus can enter your body and can
make you sick.
Practise respiratory hygiene
Cover your mouth and nose
with your bent elbow or tissue when you cough or sneeze. Then dispose of the
used tissue immediately.
Some common queries answered.
Ø Are the re differences between symptoms caused by the flu and COVID-19?
Cough and cold could mean
an allergy. A fever with cough and cold is
a symptom of the flu. When you have fever with a cough which is complicated by breathlessness, it is a symptom of Corona
virus infection and you must call your doctor to rule it out.
Ø How effective are thermal scanners in detecting people infected with the new corona virus?
Thermal scanners
are effective in detecting people
who have developed a fever (i.e. have a higher
than normal body temperature) because of infection with the new corona virus.
However, they cannot detect people who are infected but are not yet sick with fever.
This is because it takes between 2 and 10 days before people who are
infected become sick and develop a fever.
Ø Can a person exposed to Corona virus transmit it to others if he/she uses a swimming pool?
Highly unlikely. The Corona
virus is a droplet infection. It has to be inhaled to cause the disease.
Chlorination of swimming pools to recommended levels can certainly inactivate
any virus, including COVID-19.
Ø Should people avoid eating meat-based food to prevent transmission?
It is a respiratory virus
and not a food-borne one. Corona virus has nothing to do with food or pet
animals or eating chicken and mutton. People can eat whatever they want and how
much ever they want.
Ø Is there a link between a person’s immunity and COVID-19 transmission?
Coronovirus is one of the weakest
family of viruses.
The deaths caused so far or people affected could
have been ones with less immunity like children or the elderly. Sometimes, the virus
enters a person’s lungs and causes pneumonia. People with vulnerable immunity
like the elderly succumb to this. For young people with good immunity, the
effects of the virus may not be too strong but if you are someone with comorbid
conditions like diabetes or cardiac disease, or if you are on immunosuppressive
drugs, then the risk of infection is severe.
Ø Are there any home remedies to treat COVID-19?
Home remedies and
treatment other than allopathy is not proven science. The best thing is precaution only. You must keep away from a patient who coughs and sneezes. If you are coughing, you need to cover
your face with a mask and not spread the droplets around. COVID-19 spreads
through droplets.
Ø Are antibiotics effective in preventing and treating the new corona virus?
No, antibiotics do not
work against viruses, only bacteria. The new corona virus (2019-nCoV) is a
virus and, therefore, antibiotics should not be used as a means of prevention
or treatment.
However, if you are
hospitalized for the 2019-nCoV, you may receive antibiotics because bacterial
co-infection is possible.
Ø Do vaccines against pneumonia protect you against the new corona virus?
No. Vaccines against
pneumonia, such as pneumococcal vaccine and Haemophilus influenza type B (Hib) vaccine,
do not provide protection
against the new corona virus. The virus is so new and different that it needs
its own vaccine.
Although these vaccines
are not effective against 2019-nCoV, vaccination against respiratory illnesses
is highly recommended to protect your health.
Ø Myths around COVID-19
There have been several
myths around the disease, like consuming more
garlic, curry leaves
or cow’s urine would treat or protect
one from the disease.
The World Health Organization has busted such misleading claims.
On garlic, WHO said it is a healthy
food that may have some antimicrobial
properties but there is no evidence that it has prevented people from
contracting the 2019 nCoV.
Ø Here are some other myths and the WHO’s response to them:
Myth: “COVID-19
virus cannot be transmitted in areas with hot and humid climates”
From
the evidence so far, the COVID-19 virus can be transmitted in ALL AREAS,
including areas with hot and humid weather.
Regardless of
climate, adopt protective measures if you live in, or travel
to an area reporting COVID-19. The best way to protect
yourself against COVID- 19 is by frequently cleaning your hands.
By doing this you eliminate viruses that may be on your hands and avoid
infection that could occur by then
touching your eyes, mouth, and nose.
Myth: The new corona virus can be transmitted through mosquito bites.
To
date there has been no information nor evidence to suggest that the new corona
virus could be transmitted by mosquitoes. The new corona virus is a respiratory
virus which spreads primarily through droplets generated when an infected
person coughs or sneezes, or through droplets of saliva or discharge from the
nose. To protect yourself, clean your hands frequently with an alcohol-based
hand rub or wash them with soap and water. Also, avoid close contact with
anyone who is coughing and sneezing.
National and State helplines
(Please note that these numbers are subject to change.)
The new national helpline
numbers are 1075 / 1800-112-545 /011-23978046
State / UT
|
State Helpline No.
|
Andhra
Pradesh
|
0866-2410978
|
Arunachal
Pradesh
|
9436055743
|
Assam
|
6913347770
|
Bihar
|
104
|
Chhattisgarh
|
077122-35091
|
Goa
|
104
|
Gujarat
|
104
|
Haryana
|
8558893911
|
Himachal
Pradesh
|
104
|
Jharkhand
|
104
|
Karnataka
|
104
|
Kerala
|
0471-2552056
|
Madhya
Pradesh
|
0755-2527177
|
Maharashtra
|
020-26127394
|
Manipur
|
3852411668
|
Meghalaya
|
108
|
Mizoram
|
102
|
Nagaland
|
7005539653
|
Odisha
|
9439994859
|
Punjab
|
104
|
Rajasthan
|
0141-2225624
|
Sikkim
|
104
|
Tamil
Nadu
|
044-29510500
|
Telangana
|
104
|
Tripura
|
0381-2315879
|
Uttarakhand
|
104
|
Uttar
Pradesh
|
18001805145
|
West Bengal
|
3323412600
|
Andaman and
Nicobar Islands
|
03192-232102
|
Chandigarh
|
9779558282
|
Dadra
and Nagar Haveli and Daman & Diu
|
104
|
Delhi
|
011-22307145
|
Jammu
|
01912520982
|
Kashmir
|
01942440283
|
Ladakh
|
01982256462
|
Lakshadweep
|
104
|
Puducherry
|
104
|
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