Deadly poultry flu could be 'disease X' to spark pandemic
A new strain of bird flu which kills 38pc of those it infects has been identified as the most likely candidate to spark a worldwide flu pandemic.
Professor Jonathan Van-Tam, deputy chief medical officer for England with special responsibility for emergency preparedness and pandemic planning, told the 'Daily Telegraph' the virus concerning him and others most was H7N9, a flu virus circulating in poultry in China.
Scientists across the world are on high alert for what the World Health Organisation (WHO) has dubbed 'disease X' - a newly emerging pathogen that could prove as destructive as the 1918 Spanish flu which killed between 50 and 100 million people a century ago.
Prof Van-Tam said the UK government was gathering as much intelligence on the H7N9 virus as possible - looking at its geographic spread, the number of human cases and any changes in its genetic structure.
"[H7N9] is an example of another virus which has proven its ability to transmit from birds to humans.
"It's possible that it could be the cause of the next pandemic," he said.
So far 1,625 people in China are known to have been infected with the H7N9 virus, 623 of whom have died. Most of those infected have been in close contact with poultry or poultry markets.
It is unknown how long the virus has been circulating among birds but it was first identified in humans in 2013. In birds, the virus generally does not cause any symptoms, but in humans it can cause serious illness and - in almost 40pc of cases - death.
H7N9 can not yet be passed from one person to another but experiments on animals have shown it was just three mutations away from being able to do so.
People who contract H7N9 develop a high fever, cough and shortness of breath and it can rapidly progress into severe pneumonia. Those with the severe form of the disease develop acute respiratory distress syndrome - where the lungs cannot provide the body with enough oxygen - septic shock and multi-organ failure.
Pregnant women, older people and those with underlying conditions are most likely to become seriously ill or die, according to the WHO.
H7N9 belongs to a family of type A flu viruses and is closely related to avian bird flu - H5N1, which crossed into humans in 2003. Bird flu has killed around 400 people globally but has not yet sparked a worldwide pandemic.
The 1918 Spanish flu had the highest death rate of all known flu pandemics, killing between 2pc and 2.5pc of all those who contracted it globally.
However, death rates varied massively - from less than 1pc to more than 40pc - depending on susceptibility and preparedness of the communities it affected.