IDRIS Elba stunned fans when he revealed he had tested positive for coronavirus - but had no symptoms.
The revelation left many of his fans wondering how he had Covid-19 when he was not experiencing the most common symptoms of the deadly illness.
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The warning signs of coronavirus include a new or dry cough, a high temperature or shortness of breath.
However, doctors have now revealed that some people with Covid-19 may not show any of these three signs of coronavirus.
And if you don't show any symptoms - known as being 'asymptomatic' - then the risk of infecting others increases.
The number of UK cases of coronavirus have risen to 25,150 - with the death toll standing at 1,829.
The US Centers for Disease and Control said: "Some spread might be possible before people show symptoms; there have been reports of this occurring with this new coronavirus, but this is not thought to be the main way the virus spreads."
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There have been growing fears that these infected carriers are slipping under the radar and could be behind the staggering advance of the disease.
Health officials warned early on in the outbreak of the new infection that it is possible to spread through "hidden webs".
And now a newly released series of studies indicate people without Covid-19 symptoms are acting as unseen “super spreaders”.
Science journal Nature says the warning sign of “covert transmission” is finding sick people with no recent international travel or contact with anyone displaying symptoms.
The exact rate of such transmission is unknown, but inferences are it’s very high.
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Jeremy Farrar, a London-based infectious disease specialist, told Nature: “We need to make policy decisions and clinical decisions now.
“You can’t say, ‘Let’s wait a month until we have the data’.”
The dramatic outbreak in the US state of Massachusetts is a case in point.
Researchers believe at least 82 cases out of 2,000 were contracted from spreaders not yet showing symptoms.
They pointed to one key event in February, when a biotechnology company held a staff conference.
In the days after the event, three employees fell ill and tested positive for the virus.
Later, more than 70 diagnosed Covid-19 cases were traced back to the conference.
New large-scale mathematical modelling studies have exposed a significant amount of “asymptomatic” spread within Singapore and Tianjin Province, China.
One pre-print study indicates between 48 per cent and 66 per cent of 91 cases in Singapore must have contracted the virus from a carrier not showing symptoms.
In China, the figure was much higher – some 62 per cent and 77 per cent.
Another points to people being infectious on average between 2.55 and 2.89 days before the onset of symptoms.
Caroline Colijn, Simon Fraser University study’s lead author, said: “Our analysis would suggest that pre-symptomatic transmission is pretty commonplace.
“In particular, the portion of transmission events that occur before symptom onset is a central quantity for infection control … Half of all secondary infections (must) be prevented to control (its) spread."
And US Secretary of Health and Human Services Alex Azar told US media earlier this month: “You really need to just focus on the individuals that are symptomatic. And you do the classic blocking and tackling of public health: identify cases, get them diagnosed, get them treated, get them isolated, and then do the contact tracing.
“Then (we) engage in the types of community mitigation measures that bring this down – slow contact with individuals, social distancing, the full armamentarium. But it really does depend on symptomatic presentation.”
On top of this, research published recently found that those infected with Covid-19 can take a staggering five days for coronavirus symptoms to show - and they can still appear after the quarantine period.
The new study, from the Johns Hopkins Bloomberg School of Public Health in the US, found that the average incubation period is 5.1 days.
And they say that almost all - 97.5 per cent - of those who develop symptoms appeared to do so within 11.5 days of infection.
In another study, scientists from the United States, France, China and Hong Kong, found that time between cases in a chain of transmission is less than a week.
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Previously, researchers had some uncertainty about asymptomatic transmission with the coronavirus.
But they now hope that this evidence could be used to provide guidance to public health officials on how to contain the disease.