Viral respiratory diseases (including influenza and COVID-19) in Scotland surveillance report

About this release

This weekly release by Public Health Scotland presents epidemiological information on respiratory infection activity, including COVID-19, across Scotland.

As part of our continuous review of reporting, over the comings months Public Health Scotland will be implementing some changes to present a consolidated weekly respiratory publication.

Main points

Weekly respiratory main points

Overall assessment:

• The proportion of NHS24 calls that were for respiratory symptoms decreased from Moderate to Baseline activity level overall.
• The incidence rate of influenza has decreased to Moderate activity level overall.
• There were 452 influenza cases: 348 type A (not subtyped), 69 A(H3), 14 A(H1N1)pdm09 and 21 type B. This compares to 1,363 laboratory-confirmed cases reported during week 01.
• Influenza by age: The under 1, 1-4 and 5-14 age groups decreased to Low activity level, the 15-44, 45-64 and over 75 age groups decreased to Moderate activity level.
• Mycoplasma pneumoniae and parainfluenza remained at Baseline activity level. Adenovirus and rhinovirus decreased from Low to Baseline activity level. Seasonal coronavirus (non-SARS-CoV-2) decreased from Moderate to Baseline activity level.
• HMPV decreased from Moderate to Low activity level.
• RSV remained at Low activity level. The number of laboratory-confirmed RSV cases was 145. This compares with 256 laboratory-confirmed cases in week 01.
• The hospitalisation rate for influenza has been generally increasing since week 25 2022 and has seen a peak of 26.9 per 100,000 in week 51 2022 but has gradually reduced since then and was 13.2 per 100,000 in week 01-2023. The highest hospital admission rate for confirmed influenza noted in patients aged 75 and over (54.7 per 100,000), followed by those aged 1-4 years (45.1 per 100,000). 
• The hospitalisation rate for RSV was 2.5 per 100,000 in week 01 2023, with the highest hospital admission rate for confirmed RSV was noted in patients aged between one and four years old (30.7 per 100,000). The hospitalisation rate for RSV peaked in week 48 in 2022 (4.3 per 100,000).  
• In the Community Acute Respiratory Infection (CARI) sentinel surveillance system carried out at general practices across Scotland, rhinovirus has been the highest circulating pathogen in the community since the start of the season in week 40 and has had the highest swab positivity until week 49 (over all swab positivity at 18.8%), followed by influenza A, which has the highest swab positivity in the last four weeks (overall swab positivity at 14.1%) and RSV which has been high since week 40 (overall swab positivity at 10.2%).
• NB: There has been an ongoing delay in getting complete test results for all samples, caused by a technical issue at the lab on 06/12/2022. This has led to a backlog and results for the most recent week are therefore not available. Updated data for week 01 is being reported this week. Results should be interpreted with caution as further samples are still expected and any retrospective changes in swab positivity will be reported on next week.
• Influenza vaccine data show that at the end of week 02, an estimated total of 2,512,925 individuals have received their vaccine.  This includes 1,925,465 eligible adults of whom 959,539 are aged 65 years and over. In addition, 89.8% of those receiving their COVID winter booster and eligible for flu vaccine have received both vaccines at the same appointment. More detailed data for the 2022/23 winter programme are available on the PHS flu and COVID winter vaccination dashboard.
• All-cause excess mortality for week 51 (the latest week not impacted by reporting delays) increased to High activity level overall. There was an increase in the 15-64 age group to Moderate activity level and the 65 and above age group to High activity level, but the under 15 age groups remained at Baseline activity level. Although data for the most recent weeks are still incomplete, all-cause mortality in weeks 52 and 01 remains elevated in the 65+ age group. Further examination of the cause of death in these individuals reveals an increase due to a range of non-infectious and infectious conditions, including COVID-19 and other respiratory pathogens.

COVID weekly main points

• In Scotland, in the week ending 31 December 2022, the estimated number of people testing positive for COVID-19 was 219,600 (95% credible interval: 189,300 to 251,600), equating to 4.17% of the population, or around 1 in 25 people (Source: Coronavirus (COVID-19) Infection Survey, UK - Office for National Statistics)
• In the week ending 15 January 2023, there were on average 1,147 patients in hospital with COVID-19, a 11.6% decrease from the previous week ending 08 January 2023 (1,297)
• In the week ending 15 January 2023 there were 19 new admissions to Intensive Care Units (ICUs) with a laboratory confirmed test of COVID-19, an increase of 2 from the previous week (08 January 2023)
• By week ending 15 January 2023 of the 1,987,376 people vaccinated for COVID-19 as part of the Winter 2022 vaccination programme, 89.8% were vaccinated for Flu at the same vaccination appointment
• In the week ending 08 January 2023, there were 81 deaths involving COVID-19 (13 more than the previous week) (Source: National Records of Scotland)

Background

Weekly national respiratory report:

Surveillance of respiratory infection is a key public health activity as it is associated with significant morbidity and mortality during the winter months and particularly in those at risk of complications of influenza, e.g., the elderly, those with chronic health problems and pregnant women.

The spectrum of respiratory illnesses varies from asymptomatic illness to mild/moderate symptoms to severe complications including death. There is no single respiratory surveillance component that can describe the onset, severity and impact of influenza or the success of its control measures each season across a community.

This requires several complementary surveillance components which are either specific to respiratory infections or their control, or which are derived from data streams providing information of utility for other PHS specialities (corporate surveillance data). Together, the respiratory surveillance components provide a comprehensive and coherent picture on a timely basis throughout the winter respiratory season. influenza page on the HPS website (external website) for more details.

COVID-19 weekly statistical report:

Since the start of the outbreak, Public Health Scotland (PHS) has been monitoring a number of key indicators to assess the impact of the virus, including demands on the health system.

This report summarises the current COVID-19 data in Scotland, presenting statistics on estimated infection levels from the ONS COVID Infection Survey, wastewater infection levels, reported COVID-19 cases, COVID-19 hospital and ICU admissions and Flu and COVID-19 Winter 2022 Vaccination Programme uptake.

Further information

The next release of this publication will be 25 January 2023.