April 13, 2020

expert comments about comparison between the COVID-19 situation in Ireland and the UK

There have been questions from journalists on the differences between the COVID-19 situation in Ireland and the UK.

Prof Paul Hunter, Professor in Medicine, UEA, said:

“Up to the midnight last night there were 10,612 deaths in the UK (0.16 deaths/1000 population) compared to Republic of Ireland 334 (0.07 deaths/1000 population) so we are running about twice the rate as was pointed out by @laineydoyle on Twitter.

“The main reason is likely that we have rather more cases then the Irish.  Looking at reported case numbers would suggest Ireland has a higher attack rate (this is, identified cases per million of population).  However, you cannot compare reported cases from Ireland and UK because the Irish have tested at a rate of 10.7 tests/1000 population compared to our rate of only 5.2 (as of last night).  One explanation might be that in reality the UK in fact has more cases per million population.  Why the UK would have a higher attack rate than Ireland is partly because we have much bigger and more densely populated cities, London itself has twice the population of the Republic of Ireland.  We do know that the infection seems to spread most rapidly big cities.  Although Ireland only implemented a stay at home order on the 27th March four days later than the UK it did close schools some 11 days earlier.

“As well as factors that may influence the total number of cases there may also be other factors that affect death rate in infected individuals.  One possibility is the higher proportion of BAME people in UK as there is some evidence that this group are more likely to get more ill.  Also the rapid expansion in critical care beds in UK to meet demand and staffed by doctors and nurses with less experience of critical care may also be a factor.  Finally other factors such as poverty and relative deprivation could also play a part but too early to say for certain.

“But despite what I have said here, the underlying mechanisms between the differing mortality rates between the UK and Ireland are still unclear and need to be investigated very carefully to ensure that we do not miss the opportunity to reduce deaths in the UK.”

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

“The UK issued stay at home 4 days earlier than Ireland and before that we had one week of work at home and isolate if fever and cough.

“ITU bed capacity is not relevant until they fill up and that has not happened in either country.

“The most likely explanation is we got coronavirus much earlier than Ireland.  The risk of introduction is related to the number of travellers coming back with an infection.  These were very rare events and international travel is related to your population size and also business hubs (London, Lombardy and New York).  Although Ireland may have the same number of international travellers per head of population, your risk of first introductions is related to the actual number of travellers.  The UK is 13 times larger in population than Ireland and London is much more of an international centre and hub than Dublin.

“This is what probably has helped New Zealand to be late to the pandemic, far less international travellers so had much later introduction.  New Zealand is not a short hop away like Europe is for the UK.  Ireland is less connected than the UK to Europe.

“With doubling times of every 2-3 days even a later introduction of the first infections by a week can have a very large effect.

“This is my best informed guess for why.  It is certainly not ITU capacity as that is not full.”

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

www.sciencemediacentre.org/tag/covid-19

Declared interests

None received.