Coronavirus (COVID-19): Scotland's Route Map - supporting evidence - 20 August 2020 review

WHO criterion 1: Evidence shows that COVID-19 transmission is controlled

R is consistently low

Number of infectious cases is showing a sustained decline

SAGE's consensus view, as of 20 August, was that the value of R in Scotland was between 0.8 and 1.2. The various groups which report to SPI-M use different sources of data in their models (i.e. deaths, hospital admissions, cases) so their success at capturing recent local outbreaks varies from group to group, leading to increased levels of uncertainty at this point in the epidemic.

In the week to 17 August, recent levels of cases significantly exceeded what would have been expected in Perth and Kinross, Dundee, North Lanarkshire, Angus, Glasgow and Aberdeen. In most cases these are a reflection of a small number of cases nationally, however the ongoing nature of the outbreak in Perth and Kinross were a cause for concern. Levels in Aberdeenshire were falling back towards normal levels.

Supplementary measures

The number of new confirmed COVID-19 cases by specimen date showed a sustained decline since peaking in late April 2020, based on the 7 day moving average, up until 9 July, even in the context of increased testing and expanded eligibility. Mid-July saw a slight increase in confirmed cases – potentially as a result of increased detection of asymptomatic cases through Test & Protect, then, following the outbreak in Grampian, the number of new cases increased in early August, averaging over 40 per day from Aug 6 onwards.

Source: Public Health Scotland, 20 August 2020

The number of hospital admissions per day for those with a positive COVID-19 result has shown a sustained decline since 7 April 2020, based on the 7 day moving average. Between 10 July and 12 August there were a total of 24 hospital admissions for patients with confirmed COVID-19.

Source: COVID-19 Statistical Report, 19 August 2020, Public Health Scotland

The number of new daily ICU admissions has shown a sustained decline since
4 April based on the 7 day moving average. Between 10 July and 16 August 2020, there were 7 confirmed COVID-19 patients admitted to ICU, with none from 31 July to 12 August, but two in the latest week for which data is available.

Source: COVID-19 Statistical Report, 19 August 2020, Public Health Scotland

There has been a sustained decline in the number of weekly deaths among confirmed and probable cases. The number of deaths peaked in Week 17 (20 April to 26 April 2020). Three deaths were registered in the week up to Sunday 16^th August, a decrease of 2 from the previous week.

Source: https://data.gov.scot/coronavirus-covid-19/detail.html#excess_deaths

The proportion of those who have a positive test for Covid-19 out of those who are symptomatic of Covid-19 in community healthcare has seen a very small increase in the positivity rate over the last three weeks. There were no swab positives for three weeks, week 27 (29 June to 5 July) to week 29 (13 to 19 July), but one in week 30 (20 to 26 July) which represents 0.2% of swabs, three in week 31 (27 July to 2 August) which represents 0.7% of swabs and two in week 32 (3 to 9 August) which represents 0.5% of swabs.

In conclusion:

Deaths and hospital admissions remain very low and there have been 2 ICU admissions since 31 July (up to 16^th August), but an increase in case numbers has been observed.

This is the first time since March that the upper limit on R has been above 1 in Scotland. Within Grampian, cases in Aberdeen and Aberdeenshire are still exceeding what would be expected at this point in the epidemic.

On the basis of the evidence summarised above the assessment is that these criteria have been met at this review point, although vigilance is critical as new outbreaks emerge.