THE R rate for coronavirus has fallen in the south west and is currently the lowest in England, new figures show.

Last week, the south west had the highest R value range at 0.8 to 1.1.

However, the latest figures published by the Government show the rate has fallen to 0.6-0.9.

The R value is the average number of people an infected person passes the disease on to and if that figure exceeds one, the disease could rapidly spread throughout the population again.

​For the first time, the Government has published 'growth' rates for the UK.  Previously, they had only been giving details of the R value of the disease.

The growth rate reflects how quickly the number of infections is changing day by day, and, as the number of infections decreases, is another way of keeping track of the virus.

If the growth rate is greater than zero, and therefore positive, then the disease will grow, and if the growth rate is less than zero, then the disease will shrink.

It is an approximation of the change in the number of infections each day, and the size of the growth rate indicates the speed of change.

For the UK as a whole, the current growth rate is minus 4% to minus 2% and the estimate of the reproduction number, referred to as R, remains at 0.7 to 0.9.

R estimates do not indicate how quickly an epidemic is changing and different diseases with the same R can result in epidemics that grow at very different speeds.

For instance, a disease with R=2 with infection lasting years will grow much more slowly than a disease with R=2 with infection lasting days.

Growth rates provide different information from R estimates, by suggesting the size and speed of change, whereas the R value only gives data on the direction of change.

To calculate R, information on the time it takes for one set of people in an infected group to infect a new set of people in the next group is needed.

However, the growth rate is estimated using a range of data similar to R, but it does not depend on the “generation time” and so requires fewer assumptions to estimate.

Neither measure – R or growth rate – is better than the other but each provides information that is useful in monitoring the spread of a disease.

Experts say each should be considered alongside other measures of the spread of disease.

For the NHS England region, the R value is 0.7 to 0.9, and the growth rate is minus 4% to minus 1%.

The R values and growth rate for the following regions are:

  • East of England: 0.7-0.9, minus 6% to minus 1%
  • London: 0.7–1.0, minus 5% to plus 1%
  • Midlands: 0.8–1.0, minus 4% to 0%
  • North East and Yorkshire: 0.7-0.9, minus 5% to minus 1%
  • North West: 0.7–1.0, minus 4% to 0%
  • South East: 0.7–0.9, minus 5% to minus 1%
  • South West: 0.6-0.9, minus 6% to 0%