Weekly national seasonal respiratory report
Week ending 30 October 2022 – week 43

About this release

This release is a weekly report on epidemiological information on seasonal respiratory infection activity in Scotland. Due to the COVID-19 pandemic, health care services are functioning differently now compared to previous flu seasons so the consultation rates are not directly comparable to historical data.

Main points

Overall assessment:

• The proportion of NHS24 calls for respiratory symptoms remained at Baseline activity level
• Influenza incidence remained at Low activity level
• There were 183 influenza cases: 136 type A (subtype unknown), 19 A(H1N1)pdm09, 22 A(H3) and six type B. This compares to 187 laboratory-confirmed cases reported during week 42.
• Seasonal coronavirus (non-SARS-CoV-2), HMPV and Mycoplasma pneumoniae remained at Baseline activity level.
• Parainfluenza and rhinovirus decreased from Low to Baseline activity level.
• RSV remained at Low activity level. Adenovirus decreased from Moderate to Low activity level.
• The number of laboratory-confirmed RSV cases was 184. This compares with 235 laboratory-confirmed cases in week 42.

• Two NHS Boards were at Baseline, eight were at Low and four were at Moderate activity level.
• The under 1, 1-4 and 45-64 age groups remained at Low activity level. The 5-14 age group decreased from High to Low activity level. The 15-44 age group decreased from Moderate to Low activity level. The over 75 age group remained at Moderate activity level. The 65-74 age group increased from Low to Moderate .
• The majority (69.6%) of RSV detections in week 43 were in those aged under 5 years and the majority (84.8%) of diagnoses across all age groups occurred in the hospital setting.

• The hospitalisation rate for influenza has been increasing since week 25 and was 1.6 per 100,000 in week 42, with the highest hospital admission rate for confirmed influenza noted in patients aged 1 to 4 years old (5.6 per 100,000). The current hospitalisation rate for influenza is lower than that for the five previous seasons prior to the COVID-19 pandemic.
• The hospitalisation rate for RSV was 2.8 per 100,000 in week 42, with the highest hospital admission rate for confirmed RSV noted in patients aged less than one year old (139.8 per 100,000). The hospitalisation rate for RSV peaked in week 38 and 39 in 2021 (4.5 per 100,000).
• In the sentinel sources (CARI), Rhinovirus has been the highest circulating pathogen since the start of the season and has the highest swab positivity in week 43. This was followed by adenovirus which has increased from week 42, and RSV which has been fluctuating since the start of the season.
• Influenza vaccine data for the 2022/23 winter programme are now available on the PHS flu and COVID winter vaccination dashboard. These data indicate that at the end of week 43, an estimated total of 1,461,550 individuals have received their vaccine. This includes 1,206,421 eligible adults of whom 845,927 are aged 65 years and over. In addition, 93% of those receiving their COVID winter booster and eligible for flu vaccine have received both vaccines at the same appointment.

Background

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

The spectrum of respiratory illnesses vary 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 a number of 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 flu season. Please see the influenza page on the HPS website (external website) for more details.

Further information

The next release of this publication will be 9 November 2022.