June 25, 2020

expert reaction to the latest estimate of R and growth rates

The government have released the latest estimates for the R value in the UK.

Prof Keith Neal, Emeritus Professor of the Epidemiology of Infectious Diseases, University of Nottingham, said:

“It is good that R remains below 1 and that the growth rate is negative.  As the number of cases falls everybody’s risk falls.

“There are various mathematical methodologies that can be used to calculate the R value and growth rate per day.   What is important that the methods used remain consistent when reporting weekly figures so comparisons can be made.  Data for these calculations comes from a range of sources in order to get the most accurate figures.

“One factor that remains unclear is how many cases that are included in these calculations are acquired in care homes, hospitals or food processing plants.  These cases are prevented by infection control and not social distancing measures.

“When cases from sources like these are included it raises the R value as a whole, but does not reflect the true picture of transmission in the wider community which is what is actually important to the majority of people.  The smaller the area being considered the greater the effect on the R value of a cluster.

“A small cluster of COVID-19 cases can lead to an apparent rise in R which does not give the true reflection of local risk.  These clusters need to be managed using appropriate outbreak management procedures.”

https://www.gov.uk/guidance/the-r-number-in-the-uk

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

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