What is the R number in Blackpool and what does it tell us about the resort's coronavirus infection rate?

Concerns over a rise in tourists coming to Blackpool in recent weeks has led to concerns over a rise in coronavirus infections.

But what is the R number in Blackpool? And what does it tell us about the spread of coronavirus here?

The figure, widely discussed in Government press conference, tells us how many people, on average, an infected person will pass Covid-19 on to. Anything above one means the number of cases will grow exponentially.

On Friday June 5, the R rate for the North West rose to just above one.

On the same day, the R rate for England was somewhere between 0.7 and 0.9, the Government said.

On a local level, the number can fluctuate significantly from week to week, as even a fairly small outbreak can see it rise sharply.

Which is why Blackpool director of public health Dr Arif Rajpura said local figures on their own are "somewhat unreliable".

The week before, the figure in Blackpool was 1.6 - which would likely send us back into full-blown lockdown if it was like that across the country - but by Monday June 1 had fallen to 0.5, below the latest published national R rate.

What does this mean for us in Blackpool?

Dr Rajpura said the R rate for a single town, like Blackpool, could provide "a useful means of monitoring direction of travel of infection rates".

But he added: "R values are more reliable at regional level.

"A single R value at a local level cannot be used on its own to inform decisions on easing of restrictions."

The Government is not publishing local R values and in isolation, given they tend to fluctuate, the two figures we know of for Blackpool don't tell us much.

But over time, changes will help to give a clearer indication of how the virus is spreading in the resort.

Blackpool Victoria Hospital said last week admissions for Covid-19 were still increasing, Public Health England figures showed the number of confirmed cases began to rise again restrictions on daily exercise and sunbathing were lifted.

How is the R rate calculated?

It is impossible to calculate R exactly.

A range of measures are looked at the calculate the R value - including hospital admissions data, and infection surveys.

Several groups of experts, from universities and PHE, then use the information to estimate the value of R.

These figures are analysed by the Science Pandemic Influenza Modelling group, which agrees a range that R is likely to fall between.