Coronavirus (COVID-19): state of the epidemic - 18 March 2022

Summary

The daily positivity estimate from the Covid-19 Infection Survey for Scotland continued to increase in the most recent week, reaching the highest level seen in Scotland since joining the survey in October 2020. By comparison, the weekly case rate (including reinfections) in Scotland has continued to increase sharply in the most recent week, and wastewater Covid-19 RNA levels have almost tripled in the last two weeks. According to both wastewater estimates and case rates, this trend is seen across most local authorities in Scotland, and over 9% of total new cases in Scotland were reinfections in the most recent week. Omicron BA.2 is the dominant variant in Scotland and its prevalence has been increasing.

The increase in case rates can be seen across all age groups in Scotland in the most recent week. Age groups 19 and younger, 40 to 49 and 60 to 69 saw an increase of 46% compared to case rates in the previous week. By comparison, Covid-19 Infection Survey estimates that Covid-19 positivity levels are rising in all age groups apart from children of a nursery or primary school age, where the trend is uncertain. Cases among care home residents continued to rise in the most recent week.

Covid-19 related daily hospital occupancy has continued to increase in the most recent week, and we are now also seeing an increase in ICU occupancy, driven by larger numbers of short stay ICU patients. Weekly hospital admissions continue to fluctuate but have increased in numbers over the last month, while weekly ICU admissions have increased in the last week. Those aged 60 or older continue to represent the majority of hospital admissions. The weekly number of Covid-19 deaths registered by NRS increased in the week to 13 March, mostly due to a high number of deaths among those older than 64.

Key Points

• The UK Health Security Agency's (UKHSA) consensus estimate for R in Scotland as at 1 March is between 1.0 and 1.3. Both the lower and upper limit of the R value have increased since the last published figure.
• As at 1 March, the UKHSA's consensus view was that the incidence of new daily infections in Scotland was between 278 and 692 per 100,000 people.
• The latest growth rate for Scotland as at 1 March was between -1% and 3%. The upper growth limit has increased since the previous week, and the lower growth limit has remained unchanged.
• As determined through the latest weekly ONS Covid-19 Infection Survey, in Scotland, the percentage of people testing positive for Covid-19 continued to increase in the week 6 to 12 March 2022 to 7.15% (95% credible interval: 6.56% to 7.79%)^[2], equating to around 1 in 14 people (95% credible interval: 1 in 15 to 1 in 13).
• Nationwide, wastewater Covid-19 levels have shown a rapid increase in the most recent week. The week ending 15 March saw levels of 206 million gene copies per person per day (Mgc/p/d), which is almost three times higher than two weeks prior (71 Mgc/p/d).
• The sublineage Omicron BA.2 is now the dominant variant in Scotland, and its incidence is increasing. The Covid Infection Survey estimated that 5.20% (95% credible interval: 4.67 % to 5.76%) of the private residential population would test positive with a Covid-19 infection compatible with BA.2 on 9 March. Of the new cases in Scotland that were notified on 11 March from UKGov laboratories, 84.2% were S gene positive, which is used as a reasonable proxy for tracking BA.2.
• By specimen date, the seven-day combined PCR and LFD case rate (including reinfections) continued to increase sharply in Scotland in the most recent week. There were 1,587 weekly combined PCR and LFD cases per 100,000 population in the week to 12 March, which is a 38% increase from 1,151 weekly cases per 100,000 on 5 March.
• The week leading up to 12 March continued to see sharply increasing case rates (including reinfections) in all age groups compared to the week to 5 March, ranging from a 38% increase among those aged 20 to 39 to a 46% increase among those aged 19 or younger, those aged 40 to 49, and those aged 60 to 69. Cases among those aged 60 or older have increased by 44% compared to the previous week.
• In the week to 13 March, there were 744 reported cases among care home residents, which is an increase of 24% from the previous week ending 6 March (598 cases). This is lower than previous peak of 833 weekly cases in the week to 9 January 2022, but higher than the peak of 641 weekly cases in the week to 10 January 2021.
• The proportion of reinfections among total weekly cases has increased in the most recent week to 12 March to 9.6% of cases, which is the highest level of reinfections seen in the pandemic.
• In the week to and including 16 March, Covid-19 hospital occupancy increased by 32% compared to the previous week ending 9 March, and is reaching levels close to the previous peak in January 2021. Combined ICU occupancy had increased by 41% on 16 March, to a total of 41 patients, compared to a week previously. This increase is driven by a rise in short stay ICU occupancy.
• Admissions to hospital have increased over the past month but continue to fluctuate on a weekly basis, with 977 admissions to hospital in the week to 12 March. After a period of fluctuating admission numbers, the weekly number of admissions to ICU has increased in the week to 15 March to 32 patients, compared to 23 patients in the week to 8 March.
• According to data from the PHS Education Dashboard, average hospital admissions related to Covid-19 in children and young adults have continued to increase by 19% in the three-week period to 9 March (138 average weekly admissions), compared to the previous three-week period to 2 March (116 average weekly admissions).
• The overall number of Covid-19 deaths has increased by 5%, or 6 deaths, to a total of 117 deaths in the week leading up to 13 March, compared to 111 in the week leading up to 6 March. This is due to a high number of deaths among those older than 64 in the most recent week.
• In the week leading up to 13 March 2022, Na h-Eileanan Siar had the highest combined PCR and LFD weekly case rate by specimen date, reporting 2,664 cases per 100,000 population. Dundee City had the lowest weekly combined LFD and PCR case rate in the same time period, reporting 1,110 cases per 100,000.

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 and Office for National Statistics along with scientific publications and SAGE and UKHSA 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 YouGov polling surveys.