650,000 could have been infected with coronavirus in the East of England

Researchers at the University of Cambridge, who are tracking the Covid-19 pandemic, suggest more than 10% of the population of the East of England could have been infected with coronavirus.

It is estimated that 650,000 people in the region could have already had the disease although official figures show only 14,000 have been tested positive. The research suggests the overall number infected could be between 500,000 and 850,000.

For many people, Covid-19 is a mild illness and they may not realise they have had it.

The MRC Biostatistics Unit at Cambridge University is working with Public Health England to model and forecast coronavirus infections around the country. The work is being fed into the Scientific Advisory Group for Emergencies (SAGE) which advises the government.

The data from the university researchers indicates that 1,130 people a day are being infected in the East of England but that figure is falling. The information is based on information up to 10 May.

It is estimated that the number of people being infected in the region is halving every nine to 11 days.

That compares to London where the halving time is just three or four days because the outbreak started earlier in the capital. It is estimated that 16-26% of people in London could have already had coronavirus.

The unit has also estimated the R number for each health region of England.

The R value is the reproduction rate of the virus and indicates how fast it is spreading.

If R is one it means one infected person will infect one more. If it is greater than one then the disease will spread exponentially.

The figure is 0.71 in the East of England which means for every 100 people with the illness, they will passed it on to 71 and numbers will slowly decline.

Coronavirus is spreading faster in the East than in London and Midlands but slower than in the North East of England and Yorkshire.

• Click to watch a video that explains the R number