At present, scientists believe the novel coronavirus has an incubation period – the time between it entering the body and the last point at which it could cause symptoms – of around 14 days.
And anyone suspected to be infected with the deadly disease is advised to be put under quarantine for two weeks right now in China and beyond.
One UK-based expert considered the findings ‘worrying’, but suggested that only a ‘very small’ number of patients were likely to have ‘really long’ incubation periods.
WHO experts suggested that the 24-day incubation period could reflect a double exposure in a patient. The organisation said it was not considering changing the recommended quarantine time of two weeks.
The above picture shared by China’s National Microbiology Data Center shows the first-ever specimen of the novel coronavirus, known as ‘2019-nCov’, extracted from a patient
Nearly 100 people died of coronavirus yesterday on the deadliest day of the outbreak so far. Pictured, medical workers donning protective suits move a patient in an isolated ward of a hospital in Caidian district of Wuhan on February 6 during an outbreak of a new coronavirus
The new coronavirus has killed at least 910 people and infected more than 40,640 globally
The fast-spreading disease has killed at least 910 people and infected more than 40,640 globally.
People can be infected by being exposed to virus-carrying saliva or touching contaminated surfaces.
Beijing officials previously claimed that the disease could be contagious even before symptoms show.
The new revelation emerged in a study published yesterday by a group of Chinese researchers on medRxiv, a preprint site for scientific medical papers.
The report was written by 37 specialists, including Dr Zhong Nanshan, who is the leader of a team of medical experts appointed by China’s National Health Commission to deal with the novel coronavirus.
China’s Vice Premier last week ordered Wuhan officials to put all confirmed and suspected coronavirus patients as well as their close contacts and those with fever in hospitals and quarantine camps. Pictured, people wearing protective face masks covers themselves with large plastic bags to prevent the virus outside the Shanghai Railway Station on Sunday
The death toll in mainland China rose by 97, taking the number of global fatalities to 910. Pictured, Wuhan residents wear face masks while buying food inside a supermarket amid the coronavirus outbreak and after the city went into lockdown more than two weeks ago
The team collected data from 1,099 confirmed coronavirus patients at 552 hospitals in 31 Chinese provinces and municipalities, the report said.
Analysis found that the average incubation period was three days – shorter than 5.2 days suggested in a previous paper – but the range of the a patient’s incubation period could extend from zero to 24 days.
However, very few sufferers are believed to have shown symptoms after more than three weeks because the median figure is much closer to the lower end.
The new study was published yesterday by a group of Chinese experts and yet to be reviewed. WHO chief said there are tentative signs the virus was stabilising, but said there may be more infections abroad in people who have never travelled to China
Dr Michael Ryan, Executive Director of WHO Health Emergencies Programme, claimed the patients with long incubation periods very often could be outliers, or atypical cases.
Dr Ryan said: ‘A very long incubation period can reflect a double-exposure.’
He said: ‘They very often can be outliers, and they can be because of the recording of the exposure.’
Dr Ryan said the WHO was not considering changing its recommended quarantine time of two weeks.
Prof Paul Hunter, Professor in Medicine, University of East Anglia (UEA), said: ‘The suggestion that the incubation period may extend up to 24 days is definitely worrying, especially for people currently in quarantine who may, therefore, expect to spend longer is isolation.’
He added: ‘However, the median incubation period remains very short at three days. This means that a half of people who will get ill will have developed their illness within three days of the initial contact and the proportion of people with the really long incubation periods will be very small.
He also raised the possibility of patients getting infected on more than one occasion.
He said: ‘One of the issues with particularly long incubation periods is that it is often very difficult to exclude the possibility that the person had not had a second unrelated contact.
‘Nevertheless, this new information illustrates is concerning and illustrates the need to be continuingly re-evaluating our risk assessments and advice.’
The new study was funded by four Chinese authorities: Ministry of Science and Technology, National Health Commission, National Natural Science Foundation and Department of Science and Technology of Guangdong Province.
It has not been evaluated by other scientists and its findings should not be used to guide clinical practice, according to the website.
The authors also said that they could not preclude the presence of ‘super-spreaders’.
The Mayor of Wuhan, Zhou Xianwang, last month admitted that 14 medics in the city had caught the virus from one patient because the hospital had neglected the sufferer’s symptoms.
Another confirmed patient from Britain has so far spread the disease to 11 other people after catching the virus in Singapore and then heading to France for a holiday – before returning to the UK.
China’s Vice Premier demanded Communist officials of all levels take active lead in this ‘wartime condition’, or face being ‘nailed onto the pillar of historical shame forever’. Pictured, medical workers help patients infected with the coronavirus check in at a makeshift hospital
Pangolins (one pictured in Bangkok) may be the link that facilitated the spread of the virus
Nearly 100 people died of coronavirus yesterday on the deadliest day of the outbreak so far.
The death toll in mainland China rose by 97, taking the number of global fatalities to 910.
Another 3,062 cases were reported in China yesterday – an increase of 15 per cent compared to Saturday which put an end to a series of daily declines.
China said today that 27 foreigners had been infected with the virus in the country, including two of the country’s 908 deaths.
Two people have died outside mainland China, one in Hong Kong and the other in the Philippines, taking the global toll to 910.
Wuhan has put more than 25,870 beds in dedicated coronavirus hospitals and quarantine camps, but they are not enough for potential patients in the city ravaged by coronavirus. Pictured, patients are seen in a makeshift hospital converted from Wuhan International Convention and Exhibition Center in Wuhan, China’s Hubei Province, on Wednesday
A screen grab from a CCTV news programme shows China’s Vice Premier Sun Chunlan delivering her order to Communist officials at a meeting aimed to curb the outbreak
Wuhan workers started to install temporary wards in a dozen sports halls and exhibition centres last week. These facilities (one of them pictured above) are dubbed ‘fang cang’ or ‘shelter’ hospitals and would bring some 10,700 more beds to those in need
More than 360 cases of the virus have been confirmed outside China, bringing the total to at least 40,531.
The fatality toll has passed the 774 people believed to have died in the 2002-03 SARS outbreak, another viral outbreak that originated in China.
The total of more than 40,000 confirmed cases of the new virus vastly exceeds the 8,098 sickened by SARS.
The rise in China’s death toll occurs as millions of people return to work today after an extended Lunar New Year holiday.
Confirmed coronavirus cases have spiked in the city of 14 million since late last month
Hong Kong has reported seven more cases, raising its total to 36 after the virus spread at a family gathering attended by two relatives from mainland China.
Meanwhile in Japan, another 60 people on the Diamond Princess cruise ship were today confirmed to have the virus, taking the total to around 130.
Passengers on the ship have been confined to their cabins in a two-week lockdown with confirmed virus patients taken to hospital on the mainland.
World Health Organisation chief Tedros Adhanom Ghebreyesus said there are tentative signs the virus was stabilising, but said there may be more infections abroad in people who have never travelled to China.
WHAT DO WE KNOW ABOUT THE DEADLY CORONAVIRUS IN CHINA?
Someone who is infected with the Wuhan coronavirus can spread it with just a simple cough or a sneeze, scientists say.
At least 910 people with the virus are now confirmed to have died and more than 40,640 have been infected in at least 28 countries and regions. 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 Wuhan 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 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 infections 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 7,000.
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, 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 risen to 132 and cases were in excess of 6,000.
By February 5, there were more than 24,000 cases and 492 deaths.
Where does the virus come from?
According to scientists, the virus has almost certainly come 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 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.
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 similar to a coronavirus they found in bats.
There may have been an animal which acted as a middle-man, contracting it from a bat before then transmitting it to a human, researchers suggested, although details of this are less clear.
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.
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.
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 910 people out of a total of at least 40,640 officially confirmed cases – 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.
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 that date. If cases are in fact 100 times more common than the official figures, the virus may be far less dangerous than currently believed, but also far more widespread.
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 is an epidemic, which is when a disease takes hold of one community such as a country or region.
Although it has spread to dozens of countries, the outbreak is not yet classed as a pandemic, which is defined by the World Health Organization as the ‘worldwide spread of a new disease’.
The head of WHO’s global infectious hazard preparedness, Dr Sylvie Briand, said: ‘Currently we are not in a pandemic. We are at the phase where it is an epidemic with multiple foci, and we try to extinguish the transmission in each of these foci,’ the Guardian reported.
She said that most cases outside of Hubei had been ‘spillover’ from the epicentre, so the disease wasn’t actually spreading actively around the world.