The number of coronavirus cases across the world could be ten times higher than official figures show, a leading British scientist warned yesterday.
Amid rising concern over the spread of the virus, experts said the vast majority of cases were likely to have been missed.
The death toll in mainland China – the epicentre of the outbreak – has now reached 722, with 86 people dying on Friday alone and there being more than 34,400 patients infected. There have been a further 320 cases in 27 other countries, including three in Britain, and one death reported from the Philippines.
But scientists warned the rapid spread of the virus across borders, coupled with its suspected two-week incubation period and the unreliability of testing methods, made it difficult to track.
Public Health England announced last night it would be possible to test more than 1,000 people a day for suspected coronavirus in laboratories across the UK from next week.
The diagnostic test currently used in London – where only 100 cases can be tested per day – will be available at 12 centres across England, Wales, Scotland and Northern Ireland to increase capacity and speed up results.
The number of reported cases has slowed over the past two days.
But John Edmunds, a professor at the London School of Hygiene and Tropical Medicine, said modelling showed there were ‘ten times more cases than have been reported – or even more’.
He added: ‘It’s a mild disease that might be missed if somebody doesn’t seek healthcare. And none of the tests is going to be 100 per cent sensitive so it is not unusual to only capture maybe 10 per cent of the cases.’
Professor Edmunds acknowledged that predicting the true scale of the outbreak involved a degree of ‘guesswork’, adding: ‘When there are very large numbers of cases it becomes very hard to confirm them all just because of manpower. Time will tell.’
He said the coming days would show whether the containment measures put in place by China had been effective.
Experts said it was too early to tell whether the declining number of cases in recent days was ‘good news’ because so much was unknown.
Roughly 3,900 new cases were reported worldwide on Wednesday, compared with 3,700 on Thursday and 3,200 yesterday.
A group of Britons living in the Hubei province of China are due to return to the UK tomorrow. They will be quarantined at an NHS facility in Milton Keynes, unlike a previous group of nearly 100 returned Britons who have been treated at a dedicated facility in the Wirral, Merseyside.
It emerged yesterday that a businessman who became the first Briton to contract the virus fell ill after travelling to a business meeting at a luxury hotel in Singapore.
The unnamed man was one of 109 people who attended the meeting at the Grand Hyatt Singapore in January, where a number of other attendees also became ill.
When he tested positive after returning to the UK, he was taken to Guy’s and St Thomas’ infectious disease centre in London. Officials are thought to be tracking individuals he may have had contact with.
It came amid warnings that health chiefs face a race against time to prevent the virus from hitting NHS hospitals already stretched dealing with winter illnesses.
Experts say rapid progress has been made developing a vaccine but it would not be available until the end of the year at the earliest.
Yesterday it emerged that Kaletra, a combination of two drugs used to treat HIV, is being trialled on coronavirus cases in China.
World health chiefs have warned hospital staff are at risk from a global shortage of protective masks.
Chinese scientists said pangolins, the scaly mammals, may have passed the coronavirus to humans after contracting it from bats.
There was an outpouring of grief in China yesterday after Li Wenliang, the whistleblowing doctor who tried to sound the alarm about the virus, was killed by it.