A person infected with the coronavirus can spread it with a simple cough or sneeze, scientists say.
It is now confirmed that more than 1,380 people with the virus have died and more than 64,400 have been infected in at least 28 countries and regions. But experts predict that the true number of people with the disease could reach 350,000 in Wuhan alone, as they warn that it can kill up to two out of every 100 cases. This is what we know so far:
What is the coronavirus?
A coronavirus is a type of virus that can cause diseases in animals and people. Viruses break down in cells within their host and use them to reproduce and disrupt normal body functions. Coronaviruses are named after the Latin word & # 39; crown & # 39 ;, which means crown, because they are enclosed by a spiked shell that resembles a royal crown.
Wuhan's coronavirus is one that had never been seen before this outbreak. It has been named SARS-CoV-2 by the International Virus Taxonomy Committee. The name means coronavirus of severe acute respiratory syndrome 2.
Experts say the mistake, which has killed about one in 50 patients since the outbreak began in December, is a "sister,quot; of the SARS disease that affected China in 2002, so it got its name.
The disease that causes the virus has been called COVID-19, which means coronavirus 2019 disease.
Dr. Helena Maier, of the Pirbright Institute, said: & # 39; Coronaviruses are a family of viruses that infect a wide range of different species, including humans, cattle, pigs, chickens, dogs, cats and wild animals.
& # 39; Until this new coronavirus was identified, only six different coronaviruses were known to infect humans. Four of these cause a mild common cold disease, but since 2002 two new coronaviruses have emerged that can infect humans and cause more serious diseases (severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronavirus) .
It is known that coronaviruses can 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 reported publicly from the Chinese city of Wuhan, where approximately 11 million people live, after doctors began to report infections publicly on December 31.
By January 8, 59 suspected cases had been reported and seven people were in critical condition. Tests were developed for the new virus and the registered cases began to increase.
The first person died that week and, on January 16, two were dead and 41 cases were confirmed. The next day, scientists predicted that 1,700 people had been infected, possibly up to 7,000.
Only a week after that, there were more than 800 confirmed cases and those same scientists estimated that about 4,000, possibly 9,700, were infected in Wuhan alone. By that time, 26 people had died.
By January 27, it was confirmed that more than 2,800 people had been infected, 81 had died and estimates of the total number of cases ranged from 100,000 to 350,000 in Wuhan alone.
By January 29, the number of deaths had increased to 132 and the cases exceeded 6,000.
By February 5, there were more than 24,000 cases and 492 deaths.
By February 11, this had increased to more than 43,000 cases and 1,000 deaths.
A change in the way cases are confirmed on February 13 (doctors decided to start using lung scanners as a formal diagnosis, as well as laboratory tests) caused an increase in the number of cases, to more than 60,000 and 1,369 deaths .
Where does the virus come from?
According to scientists, it is almost certain that the virus comes from bats. Coronaviruses generally tend to originate in animals: it is believed that similar SARS and MERS viruses 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 the city, which has since been closed for investigation.
Although the market is officially a seafood market, other dead and live animals were sold, including wolf cubs, salamanders, snakes, peacocks, porcupines and camel meat.
A study by the Wuhan Institute of Virology, published in the February 2020 issue of the scientific journal Nature, found that the samples of viruses of genetic composition found in patients in China are 96% similar to a coronavirus found in bats.
However, there were not many bats on the market, so scientists say it was likely that there was an animal acting as an intermediary, contracting it from a bat before transmitting it to a human. It has not yet been confirmed what kind of animal this was.
Dr. Michael Skinner, a virologist at Imperial College London, did not participate in the research, but said: "The discovery definitely locates the origin of nCoV in bats in China."
"We still don't know if another species served as an intermediate host to amplify the virus, and possibly even to bring it to the market, or what species that host could have been."
So far the deaths are quite low. Why are health experts so worried?
Experts say the international community is worried about the virus because very little is known about it and it seems that it is spreading rapidly.
It is similar to SARS, which infected 8,000 people and killed almost 800 in an outbreak in Asia in 2003, as it is a type of coronavirus that infects the lungs of humans.
Another cause for concern is that nobody has immunity to the virus because they had never found it before. This means that it can cause more damage than the viruses we encounter often, such as the flu or the common cold.
Speaking in an information session in January, Oxford University professor Dr. Peter Horby said: & # 39; New viruses can spread much faster through the population than viruses that circulate all the time because We have no immunity against them.
& # 39; Most seasonal flu viruses have a lethality rate of less than one in 1,000 people. Here we are talking about a virus in which we do not fully understand the severity spectrum, but it is possible that the lethality rate is as high as two percent & # 39; & # 39 ;.
If the mortality rate is really two percent, that means that two out of every 100 patients who suffer from it will die.
"My feeling is that it is less," added Dr. Horby. & # 39; We are probably missing out on this iceberg of milder cases. But that is the current circumstance in which we are.
"The lethality rate of two percent is comparable to the Spanish flu pandemic of 1918, so it is a major concern worldwide."
How does the virus spread?
The disease can spread among people through coughing and sneezing, which makes it an extremely contagious infection. And it can also spread even before someone has symptoms.
It is believed that it travels in saliva and even through water in the eyes, therefore, close contact, kissing and sharing cutlery or utensils are risky.
Originally, it was thought that people were catching him in a live animal market in Wuhan City. But cases soon began to arise in people who had never been there, forcing doctors to realize that it was spreading from person to person.
Now there is evidence that it can spread to third parties, to someone from one person who caught it from another person.
What does the virus do to you? What are the symptoms?
Once someone has contracted the COVID-19 virus, it may take two to 14 days, or even more, for them to show any symptoms, but they can still be contagious during this time.
If they get sick and when they get sick, typical signs include a runny nose, cough, sore throat and fever (high temperature). The vast majority of patients, at least 97 percent, according to available data, will recover from these without any medical problems or help.
In a small group of patients, who appear to be mainly elderly or people with long-term illness, it can cause pneumonia. Pneumonia is an infection in which the inside of the lungs swells and fills with fluid. It makes it increasingly difficult to breathe and, if left untreated, can be fatal and suffocate people.
What have genetic tests revealed about the virus?
Scientists in China have recorded the genetic sequences of about 19 strains of the virus and delivered them to experts who work around the world.
This allows others to study them, develop tests and possibly investigate the treatment of the disease they cause.
Tests have revealed that the coronavirus did not change much, the change is known as mutation, much during the early stages of its spread.
However, the general director of the China Disease Control and Prevention Center, Gao Fu, said the virus was mutating and adapting as it spread through people.
This means that efforts to study the virus and potentially control it can be more difficult because the virus may look different each time scientists analyze it.
More studies can reveal whether the virus first infected a small number of people and then changed and spread from them, or if there were several versions of the virus from animals that developed separately.
How dangerous is the virus?
So far, the virus has killed 1,383 people out of a total of at least 64,441 officially confirmed cases, a mortality rate of about two percent. This is a mortality rate similar to the Spanish flu outbreak that, in 1918, killed about 50 million people.
However, experts say that the actual number of patients is probably considerably higher and, therefore, the mortality rate is considerably lower. Researchers at Imperial College London estimate that there were 4,000 (up to 9,700) cases in the city of Wuhan alone until January 18; officially, there were only 444 there until that date. If the cases are in fact 100 times more common than official figures, the virus may be much less dangerous than is currently believed, but also much more widespread.
Experts say that only patients with more serious illnesses are likely to seek help and, therefore, be registered; The vast majority will have only mild cold-like symptoms. For those whose conditions become more severe, there is a risk of developing pneumonia that can destroy the lungs and kill it.
Can the virus be cured?
The COVID-19 virus cannot be cured currently and is proving difficult to contain.
Antibiotics do not work against viruses, so they are out of the question. Antiviral medications may work, but the process of understanding a virus and then developing and producing medications to treat it would take years and huge amounts of money.
A coronavirus vaccine is not yet available and is not likely to be developed in time to be of any use in this outbreak, for reasons similar to the previous ones.
The National Institutes of Health of the USA. UU. And the University of Baylor in Waco, Texas, says 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 prevent them from infecting other people.
People who get the disease are in quarantine in hospitals, where their symptoms can be treated and they will be away from the uninfected public.
And airports around the world are implementing detection measures, such as having doctors in place, taking people's temperature to check for fever and using thermal tests to detect those who might be sick (the infection causes an increase in temperature).
However, it may take weeks until symptoms appear, so there is a small chance that patients will be detected at an airport.
Is this outbreak an epidemic or a pandemic?
The outbreak is an epidemic, which occurs when a disease takes over a community, such as a country or region.
Although it has spread to dozens of countries, the outbreak is not yet classified as a pandemic, which the World Health Organization defines as the "global spread of a new disease."
WHO's director of global infectious risk preparedness, Dr. Sylvie Briand, said: & # 39; We are not currently in a pandemic. We are in the phase in which it is an epidemic with multiple foci, and we try to extinguish the transmission in each one of these foci & # 39 ;, The Guardian reported.
She said that most cases outside Hubei had "spilled,quot; from the epicenter, so the disease was not actively spreading throughout the world.