What is the Coronavirus?
A
coronavirus is a type of virus which can cause illness in animals and
people. Viruses break into cells inside their host and use them to
reproduce itself and disrupt the body's normal functions.
Coronaviruses
are named after the Latin word 'corona', which means crown, because they
are encased by a spiked shell which resembles a royal crown.
The
coronavirus from Wuhan is one which has never been seen before this
outbreak. It has been named SARS-CoV-2 by the International Committee on
Taxonomy of Viruses. The name stands for
Severe Acute Respiratory
Syndrome coronavirus 2.
Experts say the
bug, which has killed around one in 50 patients since the outbreak
began in December, is a 'sister' of the SARS illness which hit China in
2002, so has been named after it.
The disease that the virus causes has been named COVID-19, which stands for coronavirus disease 2019.
Dr
Helena Maier, from the Pirbright Institute, said: 'Coronaviruses are a
family of viruses that infect a wide range of different species
including humans, cattle, pigs, chickens, dogs, cats and wild animals.
'Until
this new coronavirus was identified, there were only six different
coronaviruses known to infect humans. Four of these cause a mild common
cold-type illness, but since 2002 there has been the emergence of two
new coronaviruses that can infect humans and result in more severe
disease (Severe acute respiratory syndrome (SARS) and Middle East
respiratory syndrome (MERS) coronaviruses)
'Coronaviruses
are known to be able to occasionally jump from one species to another
and that is what happened in the case of SARS, MERS and the new
coronavirus. The animal origin of the new coronavirus is not yet
known.'
The first human
cases were publicly reported from the Chinese city of Wuhan, where
approximately 11million people live, after medics first started publicly
reporting infections on December 31,2019
By
January 8, 59 suspected cases had been reported and seven people were
in critical condition. Tests were developed for the new virus and
recorded cases started to surge
The
first person died that week and, by January 16, two were dead and 41
cases were confirmed. The next day, scientists predicted that 1,700
people had become infected, possibly up to 7,000
Where does the virus come from?
According
to scientists, the virus almost certainly came from bats. Coronaviruses
in general tend to originate in animals – the similar SARS and MERS
viruses are believed to have originated in civet cats and camels,
respectively
The first cases of
COVID-19 came from people visiting or working in a live animal market in
Wuhan, which has since been closed down for investigation
Although
the market is officially a seafood market, other dead and living
animals were being sold there, including wolf cubs, salamanders, snakes,
peacocks, porcupines and camel meat
A
study by the Wuhan Institute of Virology, published in February 2020 in
the scientific journal Nature, found that the genetic make-up virus
samples found in patients in China is 96 per cent identical to a
coronavirus they found in bats
However,
there were not many bats at the market so scientists say it was likely
there was an animal which acted as a middle-man, contracting it from a
bat before then transmitting it to a human. It has not yet been
confirmed what type of animal this was
Dr
Michael Skinner, a virologist at Imperial College London, was not
involved with the research but said: 'The discovery definitely places
the origin of nCoV in bats in China
'We
still do not know whether another species served as an intermediate
host to amplify the virus, and possibly even to bring it to the market,
nor what species that host might have been.'
So far the fatalities are quite low. Why are health experts so worried about it?
Experts
say the international community is concerned about the virus because so
little is known about it and it appears to be spreading quickly
It
is similar to SARS, which infected 8,000 people and killed nearly 800
in an outbreak in Asia in 2003, in that it is a type of coronavirus
which infects humans' lungs. It is less deadly than SARS, however, which
killed around one in 10 people, compared to approximately one in 50 for
COVID-19.
Another reason for concern
is that nobody has any immunity to the virus because they've never
encountered it before. This means it may be able to cause more damage
than viruses we come across often, like the flu or common cold
Speaking
at a briefing in January, Oxford University professor, Dr Peter Horby,
said: 'Novel viruses can spread much faster through the population than
viruses which circulate all the time because we have no immunity to
them
'Most seasonal flu viruses have a
case fatality rate of less than one in 1,000 people. Here we're talking
about a virus where we don't understand fully the severity spectrum but
it's possible the case fatality rate could be as high as two per cent.'
If the death rate is truly two per cent, that means two out of every 100 patients who get it will die.
'My
feeling is it's lower,' Dr Horby added. 'We're probably missing this
iceberg of milder cases. But that's the current circumstance we're in
'Two per cent case fatality rate is comparable to the Spanish Flu pandemic in 1918 so it is a significant concern globally.'
How does the virus spread?
The
illness can spread between people just through coughs and sneezes,
making it an extremely contagious infection. And it may also spread even
before someone has symptoms
It is
believed to travel in the saliva and even through water in the eyes,
therefore close contact, kissing, and sharing cutlery or utensils are
all risky. It can also live on surfaces, such as plastic and steel, for
up to 72 hours, meaning people can catch it by touching contaminated
surfaces
Originally, people were
thought to be catching it from a live animal market in Wuhan city. But
cases soon began to emerge in people who had never been there, which
forced medics to realise it was spreading from person to person
What does the virus do to you? What are the symptoms?
Once
someone has caught the COVID-19 virus it may take between two and 14
days, or even longer, for them to show any symptoms – but they may still
be contagious during this time
If and
when they do become ill, typical signs include a runny nose, a cough,
sore throat and a fever (high temperature). The vast majority of
patients will recover from these without any issues, and many will need
no medical help at all
In a small
group of patients, who seem mainly to be the elderly or those with
long-term illnesses, it can lead to pneumonia. Pneumonia is an infection
in which the insides of the lungs swell up and fill with fluid. It
makes it increasingly difficult to breathe and, if left untreated, can
be fatal and suffocate people
Figures
are showing that young children do not seem to be particularly badly
affected by the virus, which they say is peculiar considering their
susceptibility to flu, but it is not clear why
What have genetic tests revealed about the virus?
Scientists
in China have recorded the genetic sequences of around 19 strains of
the virus and released them to experts working around the world
This allows others to study them, develop tests and potentially look into treating the illness they cause
Examinations
have revealed the coronavirus did not change much – changing is known
as mutating – much during the early stages of its spread
However,
the director-general of China's Center for Disease Control and
Prevention, Gao Fu, said the virus was mutating and adapting as it
spread through people
This means
efforts to study the virus and to potentially control it may be made
extra difficult because the virus might look different every time
scientists analyse it
More study
may be able to reveal whether the virus first infected a small number of
people then change and spread from them, or whether there were various
versions of the virus coming from animals which have developed
separately
How dangerous is the virus?
The
virus has a death rate of around two per cent. This is a similar death
rate to the Spanish Flu outbreak which, in 1918, went on to kill around
50million people
Experts have been
conflicted since the beginning of the outbreak about whether the true
number of people who are infected is significantly higher than the
official numbers of recorded cases. Some people are expected to have
such mild symptoms that they never even realise they are ill unless
they're tested, so only the more serious cases get discovered, making
the death toll seem higher than it really is
However, an investigation into government surveillance in China said it had found no reason to believe this was true
Dr
Bruce Aylward, a World Health Organization official who went on a
mission to China, said there was no evidence that figures were only
showing the tip of the iceberg, and said recording appeared to be
accurate
Can the virus be cured?
The COVID-19 virus cannot be cured and it is proving difficult to contain
Antibiotics
do not work against viruses, so they are out of the question. Antiviral
drugs can work, but the process of understanding a virus then
developing and producing drugs to treat it would take years and huge
amounts of money
No vaccine exists for
the coronavirus yet and it's not likely one will be developed in time
to be of any use in this outbreak, for similar reasons to the above
The
National Institutes of Health in the US, and Baylor University in Waco,
Texas, say they are working on a vaccine based on what they know about
coronaviruses in general, using information from the SARS outbreak. But
this may take a year or more to develop, according to Pharmaceutical Technology
Currently,
governments and health authorities are working to contain the virus and
to care for patients who are sick and stop them infecting other people
People
who catch the illness are being quarantined in hospitals, where their
symptoms can be treated and they will be away from the uninfected
public
And airports around the world
are putting in place screening measures such as having doctors on-site,
taking people's temperatures to check for fevers and using thermal
screening to spot those who might be ill (infection causes a raised
temperature)
However, it can take
weeks for symptoms to appear, so there is only a small likelihood that
patients will be spotted up in an airport
Is this outbreak an epidemic or a pandemic?
The
outbreak was declared a pandemic on March 11,2020.
A pandemic is defined by
the World Health Organization as the 'worldwide spread of a new
disease'
Previously, the UN agency
said most cases outside of Hubei had been 'spillover' from the
epicentre, so the disease wasn't actually spreading actively around the
world.
