
The World Health Organization has upgraded China's risk to other countries as 'high' because of the deadly coronavirus outbreak and admitted the 'moderate' rating it issued last week was a mistake.

The WHO's chief is in Beijing for crisis talks and today admitted the danger of the infection spreading to other countries is higher than previously claimed and is 'very high' inside China.

A total of 15 countries or territories outside of China have now confirmed cases, with Sri Lanka and Cambodia the latest to announce and a second case diagnosed in Canada today, in the wife of the Toronto man who was the first patient.

Beijing also today saw the Wuhan coronavirus claim its 82nd death when a 50-year-old man died in hospital in the nation's capital at around 8pm local time (12pm GMT).

China has extended its New Year holiday by three days to February 2 to fight the outbreak as people have now been diagnosed with it in every corner of China, except for Tibet.

A team of scientists in the UK believe more than 100,000 people have been infected already but many of them without knowing, and expect the case and death tolls both to continue rising as the outbreak goes on.

The damage has spread to the stock markets, too, as investors fear travel cancellations and business closures, as well as growing panic outside of China, are damaging the world economy.

Researchers in Hong Kong have warned the outbreak could become a 'global epidemic' if the Chinese government doesn't start 'draconian' travel restrictions on its citizens.

Beijing insists it is continuing drastic efforts to contain the outbreak. Measures currently in place reportedly include:

Transport restrictions in Hubei province, which is home to around 60million people – most public transport has been stopped, along with flights in and out

Long distance buses have been cancelled in Beijing, Shanghai and the provinces of Chongqing and Shandong

The New Year bank holidays will continue until February 2 – an extension of three days

All of China's state-run schools will remain closed until further notice in an extension of a school holiday

No businesses in Shanghai, including supermarkets, will be allowed to reopen until February 10

Many businesses closed voluntarily before the holiday began – among them the Disney resorts in Shanghai and Hong Kong, and Starbucks and McDonald's stores in Hubei

Chinese citizens have been banned from booking holiday tours and flight and hotel packages in other countries, according to the New York Times

Buying and selling wild animals has been banned until the coronavirus outbreak is over

People are pictured queuing at Wuhan Red Cross Hospital as they wait for medical workers to see them. Hospitals in the city are overwhelmed with people, many of whom may have the virus and others who might catch it while they're there for other treatment

Workers in protective gear catch and bag a giant salamander outside the Huanan Seafood Market, where the outbreak began almost a month ago

Medical staff in Wuhan, the crisis-hit city at the centre of the outbreak, help a patient off the back of an ambulance yesterday (Photo issued today, January 27)

Thermal scanning at Sultan Iskandar Muda International Airport in Indonesia shows people's temperatures beside their heads – those who have high temperatures will be checked to see if they have a fever

The coronavirus outbreak has now killed 82 people and struck down more than 2,800. Sri Lanka and Cambodia today became the latest countries to confirm cases

The above picture shared by China's National Microbiology Data Center shows a microscopic image of the first-ever specimen of the new coronavirus, known as '2019-nCov', extracted from a patient

Wuhan, which is in near-total lockdown, can be seen deserted earlier today, January 27. People are no longer allowed in or out of the city because the government is desperately trying to stop the virus spreading

New cases today include the first to be diagnosed in Cambodia, in a Chinese national, and a second in Toronto, Canada, where the wife of the first Canadian patient is now being treated for coronavirus.

The disease's spread has seemed all but unstoppable over the last week, and scientists at Hong Kong University say more drastic action needs to be taken.

There is a risk the virus could trigger a global epidemic – when the illness spreads uncontrollably around the world – if the Chinese government doesn't clamp down on the movement of people, the researchers said.

CORONAVIRUS: WHAT WE KNOW SO FAR What is this virus? The virus has been identified as a new type of coronavirus. Coronaviruses are a large family of pathogens, most of which cause mild respiratory infections such as the common cold. But coronaviruses can also be deadly. SARS, or severe acute respiratory syndrome, is caused by a coronavirus and killed hundreds of people in China and Hong Kong in the early 2000s. Can it kill? Yes. Eighty-one people have so far died after testing positive for the virus. What are the symptoms? Its symptoms are typically a fever, cough and trouble breathing, but some patients have developed pneumonia, a potentially life-threatening infection that causes inflammation of the small air sacs in the lungs. People carrying the novel coronavirus may only have mild symptoms, such as a sore throat. They may assume they have a common cold and not seek medical attention, experts fear. How is it detected? The virus's genetic sequencing was released by scientists in China to the rest of the world to enable other countries to quickly diagnose potential new cases. This helps other countries respond quickly to disease outbreaks. To contain the virus, airports are detecting infected people with temperature checks. But as with every virus, it has an incubation period, meaning detection is not always possible because symptoms have not appeared yet. How did it start and spread? The first cases identified were among people connected to the Huanan Seafood Wholesale Market in Wuhan. Cases have since been identified elsewhere which could have been spread through human-to-human transmission. What are countries doing to prevent the spread? Countries in Asia have stepped up airport surveillance. They include Japan, South Korea, Thailand, Hong Kong, Indonesia, Malaysia and Philippines. Australia and the US are also screening patients for a high temperature, and the UK announced it will screen passengers returning from Wuhan. Is it similar to anything we've ever seen before? Experts have compared it to the 2003 outbreak of severe acute respiratory syndrome (SARS). The epidemic started in southern China and killed more than 700 people in mainland China, Hong Kong and elsewhere SCROLL DOWN TO SEE MAILONLINE'S FULL Q&A ON THE CORONAVIRUS Advertisement

'We have to be prepared that this particular epidemic may be about to become a global epidemic,' said Dr Gabriel Leung.

'Substantial, draconian measures limiting population mobility should be taken sooner, rather than later.'

Concerns about the virus have been growing as scientists say people may be passing on the virus before they even realise they are ill, and the number of predicted cases has soared dramatically.

China's health minister Ma Xiaowei said yesterday 'it seems like the ability of the virus to spread is getting stronger' and that it can be passed from person-to-person even before symptoms appear.

And researchers at Imperial College London have estimated that more than 100,000 people may be infected around the world already. The same team had previously thought the number was around 4,000, up to 10,000.

Professor Mark Harris, from the University of Leeds, said: 'Its true that the numbers... look scary.

'One positive spin is that if we are only aware of five per cent of the total cases, the implication is that 95 per cent of cases have only resulted in either mild symptoms such that the infected people did not consider it serious enough to seek medical help, or indeed the virus may be causing an inapparent infection.

'This would significantly reduce the apparent [death] rates.'

The mayor of Wuhan, where the outbreak started, has admitted he and the ruling Chinese Communist Party did not react quickly enough to the coronavirus danger.

Mayor Zhou Xianwang offered to resign earlier today when he revealed five million people managed to leave the city before he put it into lockdown.

He said: 'On one hand, we did not reveal [information] in time; on the other, we did not use effective information to improve our work to a satisfactory level.'

And he added: 'Regarding the untimely disclosure, [I] hope everyone can understand. [Coronavirus] is a contagious disease. Contagious diseases have relevant law and information needs to be disclosed according to law.'

Stock markets dipped today as fear of the coronavirus grows in Asia and around the well.

An All-Country World Index on the London Stock Exchange dropped 0.9 per cent today to its lowest level since January 9.

The Dow Jones Industrial Average in the US fell 1.5 per cent, or 439 points, with the NASDAQ Composite index falling by 1.9 per cent and the S&P 500 by 1.5 per cent.

Japan's Nikkei index had its biggest fall in five months, dropping two per cent.

The international health situation got worse over the weekend, with France, Canada and Australia declaring their first cases.

There have also now been infections confirmed in Thailand, the US, Australia, Japan, South Korea, Singapore, Malaysia, Vietnam, Nepal, Cambodia and Sri Lanka. China and the territories Macau, Hong Kong and Taiwan have had the majority of cases so far.

Thailand, where there have been at least eight confirmed diagnoses, has been the worst hit outside of China, followed by eight in Hong Kong and five in Macau, the US and Australia.

The Philippines, which is in the danger zone but still without any confirmed cases, had another scare today, with 14 people under investigation for potential infection in Manila and various other parts of the country.

In a step up in the global response, Microsoft founder Bill Gates's Bill & Melinda Gates Foundation today announced it would donate $10million (£7.64m) to help stop the outbreak and that it was already giving funding to public and private firms in China.

Meanwhile, countries around the world are taking various steps to try and stop the virus reaching their shores, from screening at airports, to warning citizens away from China and even closing borders.

In the US and Canada there have been seven confirmed cases and 64 suspected cases of the Wuhan coronavirus. The wife of an infected man in Toronto today became the seventh official diagnosis

People trying to use the subway in Beijing, China's capital some 700miles (1,152km) from Wuhan, are met by medical workers in protective clothing

An ambulance driver in protective gear delivers medical supplies on a deserted street in Wuhan, Hubei (Photo issued today, January 27)

Passengers at Nanjing South railway station have their temperatures scanned by a masked employee. The system is used to try and detect people with fevers – fever is a symptom of viral infection

The rapid-build hospital in Wuhan started to take shape today, January 27, as hundreds of people work tirelessly to build the pre-fabricated structure in a matter of days

Photos posted on social media show deserted streets in Wuhan, where the outbreak is worst and where the government has stopped public transport and blocked the roads to stop people leaving or entering the city, home to 11million people

The streets of Wuhan were empty today, January 27, as the government transport lockdown continues

People in Wuhan have complained of feeling 'trapped' in the city which is being ravaged by the illness. Roads have been closed and public transport stopped there (Pictured: A family look out of their window on the city outskirts today, January 27)

Panic has spread out of the Hubei province, where the outbreak began almost a month ago, and into the wider world. (Pictured, unverified video shows people having their temperatures taken on a plane after arriving on a runway in Milan, Italy, from Hong Kong)

A family looks out the window from their home in a neighborhood on the outskirts of Wuhan in China's central Hubei province on January 27

Mongolia today closed its land border with China and said no vehicles or pedestrians would be allowed to cross onto its land.

OUTBREAK SCUPPERS TOP-FLIGHT SPORTS EVENTS AND OLYMPIC QUALIFIERS The coronavirus outbreak and fears of it spreading further at large gatherings of people have caused a number of high-profile sporting events to be cancelled. Olympics qualifying events in boxing, women's football, women's basketball and wrestling have all been cancelled or rescheduled after having been planned to take place in Wuhan or nearby cities. A World Series event of diving and synchronised swimming scheduled for March has been cancelled. Cycling event the Tour of Hainan, planned for late February has also been cancelled. The World Indoor Athletics Championships scheduled for March in Nanjing, some 333 miles (537km) from Wuhan, are in doubt as organisers say they will monitor the situation. Advertisement

Germany has told its citizens not to go to China at all unless it is necessary.

And travellers from Wuhan or the Hubei province, where the city is located, will not be allowed the enter the territories of Macau or Hong Kong, or Malaysia.

Temperature screening is in place at airports around the world, including in the US, Canada, Europe and Australia.

Saudi Arabia's health ministry issued special hand-washing advice to its citizens 'to prevent acute respiratory tract infections' with the hashtag #coronavirus on Twitter. The advice involved using a hand towel to turn off the tap.

After originating in Hubei's capital of Wuhan, the virus has spread throughout China and across the world - with cases confirmed in around a dozen countries including as far away as France.

'Patients with influenza can transmit the infection before becoming ill but only for a day at most before symptoms develop,' said Professor Paul Hunter, from the University of East Anglia.

'The primary way that coronaviruses are spread is by ... coughs and sneezes.

'By definition once a patient is coughing and sneezing they have already developed symptoms.

'A description of the early cases suggest that on the current outbreak affected patients are less likely report upper respiratory symptoms such as sore throats and runny noses which may even reduce the risk of person to person spread early in the illness.'

The development comes as the mayor of Wuhan, Zhou Xianwan, said officials are stepping up the construction of specialised hospitals to deal with infection victims.

US President Donald Trump today tweeted: 'We are in very close communication with China concerning the virus. Very few cases reported in US, but strongly on watch. We have offered China and President Xi any help that is necessary. Our experts are extraordinary!'

A medical worker at Wuhan's Jinyintan Hospital is pictured treating a coronavirus patient who was transferred there from elsewhere in the city

A driver and passenger have their temperatures checked by people at a traffic stop in Tengzhou, Shandong

A young couple embrace while wearing face masks in Hong Kong. Hong Kong, which has had eight confirmed cases, has banned the entry of anyone travelling from Wuhan

Saudi Arabia’s health ministry released rigorous hand-washing guidance in a desperate bid to stop the virus from spreading. It included using a paper towel to handle the tap

WHAT IS CHINA'S TRAVEL SITUATION? Flights to and from China are still available – except in the Hubei province, where Wuhan is – but tourists may struggle to travel inside the country. The UK Foreign Office has advised against all travel to the Hubei province where the coronavirus spawned. The eastern city of Wuhan is under lock-down and the government has enforced an effective travel ban, meaning public buses and trains, as well as roads, have all been closed so people cannot get in or out of the city. The same measures were reportedly taken last week in at least a dozen nearby cities in Hubei, including Huanggang, Ezhou, Zhijiang, Dangyang, Qianjiang, Chibi, Xiantao, Lichuan, Jingmen, Xianning, Yichang and Enshi. China's two most major cities, Beijing and Shanghai, have announced bans on long-distance buses entering or leaving. Cruise operators including Royal Caribbean Cruises, and Costa Cruises said they had cancelled a combined 12 cruises that had been scheduled to embark from Chinese ports before February 2. Airports around the world have stepped up screening of passengers from China, although some health officials and experts have questioned the effectiveness of these efforts. Advertisement

Workers are now four days into their drastic plan to build an entire hospital from scratch in less than seven days – the spontaneous build was ordered on Thursday last week.

Incredible footage and photos revealed today show the rapid progress being made at the hospital, named the Huoshenshan or 'Fire God Mountain' Hospital, since its building was ordered last week.

A fleet of diggers all working at once has cleared space for the 1,000-bed facility and workers have now started to erect the pre-fabricated structure. One wing of the hospital was built in just 16 hours.

China's health minister, Ma Xiaowei, yesterday said authorities have cranked up efforts to stop the spread of disease after admitting that they have limited knowledge of how the virus mutates.

Mr Ma said 'it seems like the ability of the virus to spread is getting stronger' and added that the state will continue to restrict public transport and scrap planned public gatherings.

The country has also banned the sales of wild animals until the outbreak is over.

'Wet markets', like the one where the outbreak began in Wuhan, sell all manner of animals both dead and alive – bizarre creatures such as giant salamanders, koala bears, snakes and wolf puppies had all been seen there. Wild animals are believed to be the source of the virus.

President Xi Jinping said at the weekend that the country, which has the biggest population in the world with some 1.4billion people, faced a 'grave situation'.

Yet top health official Gao Fu said the coronavirus was 'not as powerful' as the SARS outbreak which rocked China in 2003, although it is becoming more contagious.

While SARS-infected people were only contagious when their symptoms were showing, coronavirus victims can infect others during their incubation period – the time between someone becoming infected and them actually feeling ill – which can be up to 14 days.

Professor Jonathan Ball, from the University of Nottingham, said this knowledge should make the World Health Organization reconsider its decision not to declare a global health emergency.

He said: 'Defining the scale of asymptomatic transmission remains key: if this is a rare event then its impact should be minimal in terms of the overall outbreak.

'But, if this transmission mode is contributing significantly then control becomes increasingly difficult. It’s looking like this coronavirus is behaving very differently to SARS and MERS, and this is a big concern.

'I would be surprised if WHO do not declare this as a Public Health Emergency of International Concern.'

Construction workers are pictured at the site where the government ordered a new hospital to be built in less than a week to help Wuhan cope with surging coronavirus cases (Photographer today, January 27)

Medical staff are pictured at Jinyintan Hospital in Wuhan, where thousands of people are infected

A company in Nantong, China, has had to step up production of its surgical masks as the country faces a shortage because people are afraid of catching the Wuhan coronavirus

What do we know about the deadly coronavirus? What are the symptoms... and how worried SHOULD the world really be?

Someone who is infected with the Wuhan coronavirus can spread it with just a simple cough or a sneeze, scientists say.

Eighty-one people with the virus are now confirmed to have died and more than 2,800 have been infected in at least 11 countries. But experts predict the true number of people with the disease could be 100,000, or even as high as 350,000 in Wuhan alone, as they warn it may kill as many as two in 100 cases. Here's what we know so far:

WHAT IS THE SITUATION IN THE US? Five people have been diagnosed with the Wuhan coronavirus in the US. The cases have been confirmed in Washington state; Chicago, Illinois; Orange County, California; Los Angeles, California; and Arizona. None of the patients have died and all are in hospital. All the patients had travelled to Wuhan, the city at the centre of the outbreak, before they became ill, CNN reported. There have been dozens of other suspected cases and people tested – the Centers for Disease Control and Prevention (CDC) said on Friday that it was monitoring 63 people in 22 states. Advertisement

WHAT IS THE SITUATION IN THE UK? No cases of the Wuhan coronavirus have been diagnosed in the UK yet. At least 73 people have been tested but all have been negative so far, according to the Government. The Government says it is now trying to work out how repatriate British citizens who are trapped in Wuhan, the city at the centre of the outbreak where all public transport and flights have been stopped. Experts and officials expect a case to be diagnosed in the UK at some point in the near future. Professor Yvonne Doyle, medical director for Public Health England, said the first case is likely to come from somebody who is already in the country. Advertisement

What is the Wuhan coronavirus?

A coronavirus is a type of virus which can cause illness in animals and people. It is an RNA virus (RNA is a type of genetic material called ribonucleic acid), which means it breaks into cells inside the host of the virus and uses them to reproduce itself.

This coronavirus from Wuhan is one which has never been seen before this outbreak. It is currently named 2019-nCoV, and does not have a more detailed name because so little is known about it.

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 seeing cases 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 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 4,500.

Just a week after that, there had been more than 800 confirmed cases and those same scientists estimated that some 4,000 – possibly 9,700 – were infected in Wuhan alone. By that point, 26 people had died.

By January 27, more than 2,800 people were confirmed to have been infected, 82 had died, and estimates of the total number of cases ranged from 100,000 to 350,000 in Wuhan alone.

Where does the virus come from?

Nobody knows for sure. 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 the virus in Wuhan came from people visiting or working in a live animal market in the city, 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.

Bats are a prime suspect – researchers at the Chinese Academy of Sciences said in a recent statement: 'The Wuhan coronavirus' natural host could be bats… but between bats and humans there may be an unknown intermediate.'

And another scientific journal article has suggested the virus first infected snakes, which may then have transmitted it to people at the market in Wuhan.

Peking University researchers analysed the genes of the coronavirus and said they most closely matched viruses which are known to affect snakes. They said: 'Results derived from our evolutionary analysis suggest for the first time that snake is the most probable wildlife animal reservoir for the 2019-nCoV,' in the Journal of Medical Virology.

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.

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.

WHAT ARE COUNTRIES DOING TO GET THEIR CITIZENS OUT OF CHINA? British ex-pats and tourists stuck in Wuhan have begged officials to 'get us out of here', venting their frustrations at the Government's response so far. About 300 Britons who live in the city are growing increasingly anxious after the number of virus cases soared by 50 per cent in just 24 hours. They accused the UK of dithering as it emerged the US, France, Spain, Australia, Japan, Thailand and Sri lanka had already organised evacuations for its citizens. France France's health minister Agnes Buzyn said officials will put 'hundreds' of citizens on a direct flight to the country later in the week. She said authorities were working on arranging a bus service to get the expats to the airport. There are some 800 French citizens stranded in the Wuhan area. She said French nationals will be held in quarantine for two weeks on arrival to stop the virus spreading on home soil. French car manufacturer Peugeot Citroen, which has a factory in Wuhan, said it was moving foreign employees and their families by bus to be quarantined in another city. The US The US State Department is organising a single flight out of Wuhan on Tuesday directly to San Francisco. It said in the event there are not enough seats, priority will be given to to individuals 'at greater risk from coronavirus' - those already showing symptoms. Officials invited US citizens with a valid passport to contact the embassy in Beijing. Private citizens are expected to later repay the travel costs, the notice said. It is reported that a Boeing 767 jet - that can carry around 230 passengers - will fly the citizens home. There are roughly 1,000 Americans living in and around the Wuhan area. Germany The German government said it was 'considering a possible evacuation of all willing German citizens' from Wuhan. On Monday January 27 it advised all citizens to avoid travelling to China at all unless the trip was necessary. Japan Japan said it planned to evacuate all of its citizens using chartered flights. It claimed it was in final discussions about the logistics with Chinese authorities. Some 430 Japanese nationals reside in or near Wuhan. The government is also considering evacuation by road from Hubei Province, and have Japanese nationals take flights home from other places, according to Japanese media. Spain Spain's foreign minister Arancha Gonzalez tweeted this morning that Spanish official are trying to evacuate 20 Spaniards stranded in Hubei province. She did not provide further details. Thailand The government is meeting today to discuss how to evacuate the 70 known expats living in Wuhan, most of whom are students. Air force commander ACM Manat Wongwat said that up to four planes with medical staff are on stand-by to evacuate its citizens in the coming days. Sri Lanka Officials have applied for a chartered plane to be allowed to land at Wuhan airport and pick up 32 Sri Lankan students and their family members stranded in the outbreak's epicentre. Its foreign office also said it was working to bring back all other citizens living in the wider Hubei province. There are about 860 Sri Lankan students are in China. Australia Foreign Minister Marise Payne said her government is 'exploring all opportunities' to help with evacuation of a number of Australians reportedly in Wuhan. There are thought to be a small number of citizens living in the central Chinese city. India India has asked China if it can make arrangements for its expats to leave. It is not clear how and when India plans to evacuate its citizens if approval is granted. Around 250 Indians are still in Wuhan. Advertisement

'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.

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.

There is now evidence that it can spread third hand – to someone from a person who caught it from another person.

What does the virus do to you? What are the symptoms?

Once someone has caught the virus it may take between two and 14 days 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 – at least 97 per cent, based on available data – will recover from these without any issues or medical help.

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.

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, yesterday 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 so far killed 82 people out of a total of at least 2,800 officially confirmed cases – a death rate of around three per cent. This is a higher death rate than the Spanish Flu outbreak which, in 1918, went on to kill around 50million people.

However, experts say the true number of patients is likely considerably higher and therefore the death rate considerably lower. Imperial College London researchers estimate that there were 4,000 (up to 9,700) cases in Wuhan city alone up to January 18 – officially there were only 444 there to date. If cases are in fact 100 times more common than the official figures, the virus may be far less dangerous than currently believed.

Experts say it is likely only the most seriously ill patients are seeking help and are therefore recorded – the vast majority will have only mild, cold-like symptoms. For those whose conditions do become more severe, there is a risk of developing pneumonia which can destroy the lungs and kill you.

Can the virus be cured?

The Wuhan coronavirus cannot currently 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, 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 has not officially been confirmed as either an epidemic or a pandemic yet. This is likely because, despite the global concern, the number of people who have been confirmed to be infected is still relatively low.

A pandemic is defined by the World Health Organization as the 'worldwide spread of a new disease'.

An epidemic is when a disease takes hold of a smaller community, such as a single country, region or continent.