Up to 4,500 patients in China may have caught the same strain of coronavirus that has killed two people, scientists fear.
Health officials in Wuhan – the city at the heart of the outbreak which started in December – confirmed four new cases today, taking the total to 48.
But Imperial College London researchers say this may be the ‘tip of the iceberg’ after analysing flights out of the city.
Experts say the fact three Chinese tourists have tested positive for the virus outside Wuhan indicates the disease toll may be higher than reported.
They estimated there has been 1,700 cases of the coronavirus – which has never before seen in humans. But they added it could have passed 4,000.
Thailand today announced a second confirmed case of the coronavirus in a woman who had travelled from Wuhan. Japan reported its first case on Thursday.
Two men in their sixties in Wuhan have already died in the outbreak, which has left health chiefs scrambling to contain the virus amid fears it will spread.
People carrying the novel coronavirus may only have mild symptoms, such as a sore throat, and assume they have a common cold, British scientists warned.
Up to 4,500 patients in China may have caught the same strain of coronavirus that has killed two people, scientists fear. Health officials in Wuhan – the city at the heart of the outbreak – confirmed four new cases today, taking the total to 48
People carrying the novel coronavirus may only have mild symptoms and assume they have a common cold, British scientists warned. Pictured, a woman wearing a mask while walking past the closed Huanan Seafood Wholesale Market, which has been linked to cases of Coronavirus
Some 1.4billion Chinese citizens will be travelling abroad during Lunar New Year. Pictured, a notice for passengers from Wuhan is displayed in Japan, where one case has been detected
Professor Neil Ferguson, who led the research, told MailOnline: ‘Our main estimate is 1,700, but the range means we are 95 per cent sure the real number relies within 190 and over 4,000.
‘I became more concerned when cases were detected in places other than China. Generally when we see cases overseas it implies there are more cases.
‘There have been three cases detected overseas. There is about one in 600 chance each case would happen to be getting on a plane and going somewhere.
‘If that’s the case, it would imply there is 1,700 cases in Wuhan itself. Which is a lot more that has been so far confirmed. There have to be a lot more cases.’
A total of 48 people who have pneumonia-like symptoms have now tested positive for the coronavirus, Wuhan Municipal Health Commission has said.
Four new cases were revealed today, all of whom were male and fell ill between January 5 and 8, and hospitalised between January 8 and 13. They are now in a stable condition at Jinyintan Hospital.
‘We don’t know if this is the tip of the iceberg. We need more information, we only have scant details,’ Professor Ferguson said.
He investigated the spate of cases in Wuhan city with colleagues at MRC Centre for Global Infectious Disease Analysis and Modelling, a branch of Imperial College London which provides advice for new diseases.
Professor Neil Ferguson said: ‘I became more concerned when cases were detected in places other than China.’ Pictured, medical staff transferring patients between hospitals in Wuhan
Japan confirmed its first case of infection from the new virus – a man in his 30s from Tokyo who had recently visited Wuhan. Pictured, pedestrians in Tokyo wearing protective masks
Using flight data, they reported that 3,300 people in Wuhan fly internationally per day, and Wuhan International Airport has a catchment population of 19million individuals.
Based on these figures, and the time it takes for symptoms to onset, they calculated that there is only a one in 574 chance that a person infected in Wuhan would travel overseas before they sought medical care in their holiday destination.
Using the number of cases detected outside China, researchers estimated how many people within Wuhan city may carry the virus.
Three travellers from Wuhan have tested positive for the coronavirus outside China, which implies there might have been over 1,700 cases in Wuhan so far.
But researchers add the estimated figure could be anywhere from 190 cases to 4,471 based on different scenarios.
The report concludes: ‘It is likely that the Wuhan outbreak of a novel coronavirus has caused substantially more cases of moderate or severe respiratory illness than currently reported.’
The new coronavirus, which is yet to be named, causes cold-like symptoms including a runny nose, headache, cough, sore throat and a fever.
Professor Ferguson said: ‘It’s winter, it’s an enormous city with lots of people with cold and flu. People would realise they were feeling ill, but not that they have the coronavirus.
‘We want to start recommendation from this that surveillance needs to be enhanced across the city, looking for people that are reporting even flu-like symptoms.
‘They need to start looking generally in hospitals for people with respiratory symptoms – that might be happening already but we don’t know.’
Forty-five cases have been contained in the Chinese city of Wuhan since December. The majority of patients have been traced to the Huanan Wholesale Seafood Market (pictured)
Some 1.4billion Chinese citizens will be travelling abroad during Lunar New Year. Airports have stepped up surveillance, including in Japan (pictured)
The second case in Thailand was reported on January 17. A 74-year-old tourist was intercepted at Thailand’s biggest airport Suvarnabhumi. Pictured, Bangkok airport staff performing thermal scans on a traveller
The report added that if cases are this high, substantial human to human transmission can’t be ruled out.
It flies in the face of statements from the World Health Organization (WHO), which state there is ‘limited’ to zero evidence that humans can spread the virus.
Investigations have focused on animals as the source because the majority of the infected patients in Wuhan have been traced to the Huanan Wholesale Seafood Market, which has been shut down since January 1.
The WHO has said ‘much remains to be understood’ about the coronavirus, which has been described as ‘novel’.
Although the genetic sequence of the strain has now been released, scientists are still questioning how deadly it is, and whether it can be spread between humans.
Professor Ferguson said information like this tends to come to light around one month after the outbreak begins, but relies heavily on co-operation from China.
He said: ‘We need more systemic data from China. Their only really two weeks from discovering this and I suspect they are focusing on collecting data.
‘We really don’t know the spectrum for the disease severity is.’
Fears of global spread have increased after Thailand announced it has detected a second case of the virus in a 74-year-old woman.
Local authorities have confirmed that a second person in Wuhan has died of a pneumonia-like virus since the outbreak started in December. Pictured, Wuhan Jinyintan Hospital
Authorities said she had been quarantined since her arrival at Thailand’s biggest airport Suvarnabhumi on January 13. She lived in Wuhan.
She is being treated in the same hospital, east of Bangkok, as a Chinese woman who was diagnosed with the virus after entering the country last week.
The 61-year-old, also from Wuhan, was the first case of the coronavirus to be detected outside of China on January 8.
Yesterday, Japan’s health ministry announced its first case, a man who had been hospitalised with pneumonia symptoms after travelling to Wuhan earlier this month.
Though the known cases of the pneumonia outbreak so far involve only individuals who have travelled to or live in Wuhan, the WHO has warned that a wider outbreak is possible.
It comes just days before Lunar New Year holidays next week, when nearly a million Chinese visitors are expected to arrive in Thailand.
Some 1.4billion Chinese citizens will be travelling abroad, leaving airports scrambling to implement surveillance in Singapore, Hong Kong, Indonesia, Thailand and Japan.
The first patient diagnosed with the novel strain, a 61-year-old man, died on January 9. The second death, a man known only as Xiong, died on January 15.
Both suffered other health problems, the former from abdominal tumours and chronic liver disease and the latter of severe cardiomyopathy – a heart condition, abnormal kidney function, and seriously damaged organs.
But it is not clear if these were complications of the virus or underlying conditions.
