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.

REVISION 13 January 2023:

The Main Points section was revised. Additional context was added to the seventh bullet point as it was incorrectly stated that the number of hospitalised patients who tested positive for influenza in week 52 was higher than any week since the 2016/17 season.

The Main Points section was revised. The tenth bullet point incorrectly stated that the estimated total number of flu vaccinations was 2,486,266

Section 4 (Influenza seasonal vaccine programme: Vaccine uptake) was revised.  The estimated total number of flu vaccinations has been updated to the correct total of 2,487,134.  It was previously reported incorrectly as 2,486,266.

Main points

Weekly respiratory main points

Due to the festive period, the laboratory confirmed diagnoses data included in this week’s report may not be complete, should be interpreted with caution and is subject to change.

Overall assessment:

• The proportion of NHS24 calls that were for respiratory symptoms increased from Moderate to High activity level
• The incidence rate of influenza has decreased but has remained at Extraordinary activity level overall.
  • There were 2,279 influenza cases: 1,800 type A (subtype unknown), 334 A(H3), 117 A(H1N1)pdm09 and 28 type B. This compares to 2,727 laboratory-confirmed cases reported during week 51.
  • Influenza by age: each individual age group remained at Extraordinary activity level.
  • Influenza by NHS Board: four NHS Boards were at Moderate, one was at High and nine were at Extraordinary activity level.
• Parainfluenza and rhinovirus decreased from Low to Baseline activity level. Mycoplasma pneumoniae remained at Baseline.
• Adenovirus decreased from Moderate to Low activity level. HMPV decreased from High to Low activity level.
• Seasonal coronavirus (non-SARS-CoV-2) remained at Moderate activity level.
• RSV remained at Moderate activity level. The number of laboratory-confirmed RSV cases was 265. This compares with 320 laboratory-confirmed cases in week 51.
• The hospitalisation rate for influenza has been generally increasing since week 25 and was 23.1 per 100,000 in week 52, with the highest hospital admission rate for confirmed influenza noted in patients aged less than one year old (113.1 per 100,000). The number of hospitalised patients who tested positive for influenza reported in week 52 is higher than that reported for any week since the start of the 2016/2017 season (except for week 51)^R. 
• The hospitalisation rate for RSV was 3.2 per 100,000 in week 52, with the highest hospital admission rate for confirmed RSV noted in patients aged less than one year old (84.3 per 100,000). The hospitalisation rate for RSV peaked in week 38 and 39 in 2021 (4.5 per 100,000).
• In the Community Acute Respiratory Infection (CARI) sentinel surveillance system carried out at general practices across Scotland, rhinovirus was the highest circulating pathogen in the community since the start of the season in week 40 until week 49, followed by RSV for many weeks, and influenza A since week 40.
  • NB: There has been an ongoing delay in getting complete test results for all CARI samples, caused by a technical issue at the lab on 06/12/2022. This has led to a backlog. Results for the most recent weeks should therefore be interpreted with caution as further samples are still expected and any retrospective changes in swab positivity will be reported next week.
• Influenza vaccine data show that at the end of week 52, an estimated total of 2,487,134^R individuals have received their vaccine. This includes 1,913,756 eligible adults of whom 959,950 are aged 65 years and over. In addition, 90.0% 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 (of which a proportion will be due to an infectious respiratory cause) for week 49 increased to Low activity level overall, but remained at Baseline activity level for all individual age categories. Although data for week 50 and later are still incomplete, all-cause mortality has increased to Moderate activity level for the All-Ages category and those aged 65 years and older.

COVID weekly main points

• In Scotland, in the week ending 08 December 2022, the estimated number of people testing positive for COVID-19 was 130,900 (95% credible interval: 111,100 to 153,400), equating to 2.49% of the population, or around 1 in 40 people (Source: Coronavirus (COVID-19) Infection Survey, UK - Office for National Statistics)
• In the week ending 01 January 2023, there were on average 1,267 patients in hospital with COVID-19, a 15.1% increase from the previous week ending 25 December 2022 (1,101)
• In the week ending 01 January 2023 there were 14 new admissions to Intensive Care Units (ICUs) with a laboratory confirmed test of COVID-19, an increase of 2 from the previous week (25 December 2022)
• By week ending 01 January 2023 of the 1,972,085 people vaccinated for COVID-19 as part of the Winter 2022 vaccination programme, 90% were vaccinated for Flu at the same vaccination appointment
• In the week ending 18 December 2022, there were 38 deaths involving COVID-19 (3 fewer 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, reproduction (R) number, 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 11 January 2023.