Publication - Research and analysis

Coronavirus (COVID-19): state of the epidemic - 16 April 2021

Published: 16 Apr 2021

This report brings together the different sources of evidence and data about the Covid epidemic to summarise the current situation, why we are at that place, and what is likely to happen next

Coronavirus (COVID-19): state of the epidemic - 16 April 2021
Method

Method

This report brings together a wide range of publically available figures from a range of data sources. These include publications by Scottish Government, Public Heath Scotland, National Records of Scotland, Office for National Statistics along with scientific publications and SAGE summaries where appropriate to summarise the state of the epidemic in Scotland in a given week. We also provide information on public attitudes to the virus from weekly You Gov polling surveys.

The national picture

The latest R value for Scotland (published on 15 April)[2] has remained the same this week and was between 0.8 and 1.0 (Figure 1), with a growth rate of between -4% and 0%.

Figure 1: R in Scotland over time
The R number has varied over the pandemic with the estimated range moving above 1 in Autumn 2020 and January 2021. For the number of infectious people to fall we need to keep the R number consistently below 1. The latest R value for Scotland (published on 15th April) has remained between 0.8 to 1.0 compared to the previous weeks estimate of between 0.8 and 1.0 (Figure 1), with a growth rate of between -4% and 0% implying that the number of infectious people is still falling.

Since they were introduced in early January at a national level we have seen the impact of stay at home measures in reducing the level of SARS-CoV-2 in Scotland. An average of 250 cases were reported per day in the 7 days to 15 April, this is a 24% decrease from the daily average cases recorded a week earlier to 8 April[3]. Average daily cases reported are now around a tenth of the peak of 2,323 in the week to 7 January. Our current position is 34 weekly cases per 100,000 in the week to 12 April[4]. This compares to 302 weekly cases per 100,000 on 8 January and is similar to the weekly case rate observed on 21 September (see Figure 2)[4].

The number of locations where the levels of Covid in wastewater are monitored has increased from 28 to 97 sites around Scotland. In contrast to COVID-19 case records, virus shedding into wastewater is a biological process. This means that wastewater data is unaffected by factors that impact whether testing is done. The overall level of wastewater RNA was similar to last week, consistent with a slow decline in the rate of new cases.

Figure 2: Seven day case rate for Scotland by specimen date. Refers to PCR testing only.
The weekly case rate of diagnosed infection is defined as the number of newly reported, laboratory confirmed cases of SAR-CoV-2 per 100,000 population. This case rate rose from a low of 24.7 in September to 170.1 in October. It then reduced and levelled off at just over 100 by the beginning of December. At the end of December it rose sharply to just over 300 at the start of January.  It has been decreasing since then but three weeks ago there was a small increase and then it plateaued for two weeks. It has started to decrease again in the last three weeks. The weekly case rate is 34 as at 12th April and is now similar to the weekly case rate observed on 21 September.

Case rates in all age groups have decreased, with a sharpest decline in cases in those aged 60+ this week (Figure 3).

Figure 3: Seven day case rate in Scotland by age group by specimen date [5]. Refers to PCR testing only.
Figure 3 shows the seven day case rates per 100,000 for five different age bands over time.  Each age band shows a similar trend with a peak in cases in January, with the 00-19 age band having the highest case rate and the over 80s age band having the lowest case rate. The case rates in all age groups have decreased further with the sharpest decrease in cases in the over 60s this week.

Not everyone who has the virus will be tested, as many people do not realise they have COVID, or have mild symptoms and do not come forward. Latest modelled estimates suggest there are currently anywhere between 200 and 1,500 people infected in Scotland each day[2]. This means that as of 14 April there were between 4 and 28 new daily infections per 100,000 people.

The number of people in hospital with confirmed Covid for less than 28 days is declining. After peaking at 2,053 on 22 January, this figure has decreased and as of 8 April there were 115 patients in hospital with COVID-19. In addition, there was a fall in daily hospital admissions for people with Covid from a peak of 242 on 11 January to 10 on 11 April[6].

There were 34 deaths registered where Covid was mentioned on the death certificate in the week to 11 April. This is an 11% decrease on the week before (38 deaths), and 95% lower than the peak in April 2020 (663 deaths). The proportion of deaths in care homes has decreased from 36% in mid-December to 15% of total deaths in the week to 11 April. However, this has increased from 9% in the week to 21 March. Deaths involving coronavirus have declined most in those aged 75-84 and have gone down by 70% in this age group over the 3 weeks to 11 April[7] (Figure 4). Deaths in those aged 15-44, 65-74, 45-64 and 85+ have declined by 50%, 47%, 30% and 29% respectively over the same period.

Figure 4: Deaths by age group (weekly total by week beginning, NRS) [7]
This figure shows the number of deaths over time for seven different age groups. In April 2020 the number of deaths in the four age groups for 45+ reached a peak with the highest number of deaths being in the 85+ group.  Deaths then declined steeply and the number of deaths were very low in all age groups during July to September.  In October the number of deaths started to increase and then plateaued during November and December for the four age groups 45+. At the end of December deaths rose steeply again to another peak in January with the highest deaths being in the 85+ group. The number of deaths has since declined steeply with the largest decrease in the 85+ age group observed first followed by a sharp decline in the 75-84 age group. Over the last three weeks to 11 April, deaths is those aged 75-84 have gone down by 70%. Similarly in those aged 45-64, 65-74 and over 80s deaths have gone down by 30%, 47% and 29% respectively. Deaths in the under 44s have remained very low throughout the whole period.

How Scotland compares with the rest of the UK

The latest ONS survey estimates that the proportion of the population infected in the community in Scotland (0.20% people currently testing positive for COVID-19 on 4 -10 April) has decreased slightly since last week and is now below England (0.21%), and above Northern Ireland (0.14%) and Wales (0.11%). In the week to the 10 April the estimated rate of community infection was 1 in 500 people in Scotland, compared to 1 in 480 for England, 1 in 920 for Wales and 1 in 710 for Northern Ireland[8]. Average daily deaths in Scotland (0.04 per 100,000 in the week to 15 April) are below Northern Ireland (0.07), but in line with England (0.04), and Wales (0.04). The Coronavirus Infection Survey estimated that in the week to 28 March, 46.0% of the population in Scotland would have tested positive for antibodies against COVID-19. This compares to 54.9% in England, 49.1% in Wales, and 54.5% in Northern Ireland[9].

Situation by local authority within Scotland

Clackmannanshire currently has the highest case rates in Scotland with 81 weekly cases being reported per 100,000 in the week to 12 April. This is a decrease of 53% from the week to 5 April[4]. There are mostly moderate and low levels of cases across Scotland, with higher levels of cases observed across the central belt (Figure 5). Most Local Authorities recorded a fall in cases in the last week, however Moray saw a 75% increase in its case rates (from 29 to 51 weekly cases per 100,000) in the period of 5-12 April. Angus, Argyll and Bute, Dumfries and Galloway, Midlothian and Scottish Borders each have fewer than 10 weekly cases per 100,000. Na h-Eileanan Siar and Orkney each had 0 cases per 100,000 in the last week[4].

Figure 5: Map of weekly new positive cases per 100,000 people in Scotland
This colour coded map of Scotland shows the different rates of weekly positive cases per 100,000 across Scotland’s Local Authorities. The colours range from green with under 1 weekly case, through light blue with 1 – 20 weekly cases, dark blue 20-50 weekly cases,  purple 50-150 weekly cases and red with over 150 weekly cases per 100,000. Clackmannanshire has the highest case rate in Scotland with 81 weekly cases being reported per 100,000 in the week to 12th April. Na h-Eileanan Siar and Orkney are showing as green with no cases per 100,000 population. All other Local Authorities are showing as light blue, dark blue or purple.

The most recent modelling predicts that for the week ending 1 May, there are no local authorities with at least a 75% probability exceeding 50 cases per 100,000 population (Figure 6)[2].

Figure 6: Maps of probability of Local Authorities exceeding 50, 100, 300 and 500 cases per 100,000 population in the period 25 April – 1 May 2021 [10]
This figure shows the probability of Local Authorities having more than 50, 100, 300 and 500 cases per 100,000 population. Hotspot is defined as an area that is predicted to exceed the cases threshold. The most recent modelling predicts that for the week ending 1 May, there are no local authorities with at least a 75% probability exceeding 50 cases per 100,000 population.

Children and Education

Children in early learning and childcare and those in primaries 1-3 went back to school or nursery on 22 February, and all children in primaries 4-7 went back on the 15 March. There has also been a phased return to secondary schools, with some Senior Phase (S4-S6) pupils returning to school on a part-time basis to attend practical lessons from the 22 February and all secondary school pupils (S1-S6) returning on a part-time basis from the 15 March. All children and young people are expected to return to full time education on the 12th or 19th April.

Over the last week there was a decrease in the total number of COVID-19 cases in children, which has gone down from 776 cases in the week to 4 April to 471 cases in the week ending 11 April. This is lower than in any week since September. The sharpest fall in 7 day cases per 100,000 was observed in those aged 5-11 (Figure 7)[11], with the highest proportion of cases still observed in those under 12 (258 cases). There has been a decrease in testing amongst most age groups in week ending 11 April, with a slight increase in those aged 16-17. Test positivity rates have increased in those aged 2-4, 5-11 and 16-17, however decreased in those aged 12-15 and 18-19 in the same period[11]. Overall, the proportion of school, early learning and childcare settings with incidents remains low.

Figure 7: Seven day case rate in Scotland by age group by specimen date for children. Refers to PCR testing only.
This figure shows the 7-day case rate of school pupils who tested positive for COVID-19, grouped in four age groups, during the period 1 November 2020 to 4 April 2021. The rates for all age groups have varied over time with a sharp increase in rates for all groups at the start of January, with the 16/17 age group or S4-S6 school year group with the highest rate. The rates reduced back down to their lowest levels at the beginning of February. The rates for all age groups, except for age 16-17, have decreased in the week to 11 April, with the sharpest fall in 7 day cases per 100,000 observed in those aged 5-11.

Looking ahead

Changes in patterns of mixing and adherence to restrictions will impact on future case numbers. The Scottish Contact Survey measures times and settings that people mix where they could potentially spread Covid[2]. From this survey we can say that contacts are still higher than seen during the lockdown period (averaging around 3 daily contacts) but have decreased slightly in the last two weeks, with a current level of 3.5 daily contacts. Contacts within the work setting have shown a decrease in the last two weeks by 25% and 36% respectively, coinciding with spring holidays that commenced from 26th March. Mean contacts in the home setting have increased by approximately 16% over the same period. Those aged under 50 have shown a decrease in overall contacts whereas those aged 50 and over have increased their contacts. Although the older population have increased their contacts in the last two weeks, daily cases and deaths have declined over the same period.

Self-reported compliance with the current regulations and guidance has decreased since January but remains at a high level. On 13-14 April, 74% of people reported 'complete' or 'almost complete' compliance[12].

Hospital bed and ICU occupancy are projected to fall over the next few weeks, but these both may plateau or increase as a result of schools reopening and other relaxations of non-pharmaceutical interventions[2].

Vaccinations are continuing across the priority groups and almost 60% of the adult population in Scotland has now been vaccinated with the first dose[4]. The first vaccines were administered on Tuesday 8 of December and 2,708,691 had received their first dose by 15 April 2021, a 4% increase from the 8 April[3]. By the 15 April over 34,000 residents in care homes had received their first vaccination along with over 52,000 care home staff. In older adult care homes almost 90% of residents have now received their second dose. By age group, almost 100% of individuals aged 55+ and 88% of those aged 50-54 had received their first vaccination (Figure 8). 69% of the over 80s and 38% of those aged 75-79 have received their second dose. Overall, 661,975 (14.6%) of those aged 16 and had received their second dose by 15 April[6]. There are continual decreasing hospitalisations and deaths among those groups vaccinated first (Figure 4).

Figure 8: Estimated percentage of people vaccinated by 15 April 2021
The first vaccines were administered on Tuesday 8 of December and 2,708,691 had received their first dose by 15th April 2021, a 4% increase from the 8th April. For the ten age groups identified, five groups have more than 98% vaccinated (everyone over age 60) and for age group 70-79, 100%, for age group 55-59, 97%, and for those aged between 50-54, 88%, have been vaccinated.  69% of over 80s have received their second dose by 15th April.

The proportion of people surveyed who said they would be likely to be vaccinated for COVID-19 remains high. 63% of all respondents have already received at least their first vaccine dose. Of those not vaccinated, 75% report they are likely to be vaccinated when a vaccine becomes available to them[13].

How the virus is changing

The variant of the virus commonly known as the UK variant (VOC-20DEC-01) has been increasing its share of confirmed cases since it was first detected in Scotland in mid-December and is now the dominant strain[14]. This new variant of Covid is more transmissible[15]. It is likely that infection with this variant is associated with an increased risk of hospitalisation and death compared to infection with non-VOC viruses[16].

Other variants of concern (VOCs) are being monitored by sequencing of SARS-CoV-2 samples. To date there are four VOCs and six variants under investigation[17]. Up to 14 April, there have been 32 genomically confirmed cases of the variant VOC-20DEC-02 (first seen in South Africa) detected in Scotland. There have been 6 confirmed cases of the variant VOC-21JAN-02 (first identified from Brazil). There have also been a number of cases of other variants, which are currently under investigation, including 26 cases of B.1.525, first seen in Nigeria. There is some concern, that some of these new variants may partially escape immunity, from both natural infection and from vaccines currently being deployed, and we are monitoring the evidence on this[18 19 20].


Contact

Email: modellingcoronavirus@gov.scot