Weekly national seasonal respiratory report
Week ending 18 September 2022 – week 37

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 in week 37 was at Baseline activity level. The 5-14, 15-44, 45-64, 65-74 and over 75 age groups remained at Baseline activity level. The under 1 and 1-4 age groups remained at Moderate activity level.
• There were 69 influenza cases: 50 type A (subtype unknown), eight A(H1N1)pdm09, five A(H3), and six type B. This compares to 52 laboratory-confirmed cases reported during week 36. Influenza incidence remained at Baseline activity level
• In week 37, coronavirus (non-SARS-CoV-2), HMPV, parainfluenza, and Mycoplasma pneumoniae remained at Baseline activity level. Adenovirus, RSV and rhinovirus were at Low activity level.
• RSV remained at Low activity level in week 37. The number of laboratory-confirmed RSV cases for week 37 was 147. This compares with 145 laboratory-confirmed cases in week 36. RSV cases are greater than what would be expected at this time of the year.
• Five NHS Boards were at Baseline, five were at Low, three were at Moderate and one was at High activity level.
• All age groups remained at Low activity level.
• The majority (71%) of RSV detections in week 37 were in those aged under 5 years and the majority (86%) of diagnoses across all age groups occurred in the hospital setting.
• The hospitalisation rate for influenza was 0.8 per 100,000 in week 37, with the highest hospital admission rate for confirmed influenza noted in patients aged one to four years old (4.2 per 100,000). The highest hospitalisation rate for influenza this season was reported in week 11 (1.3 per 100,000).
• The hospitalisation rate for RSV was 2.1 per 100,000 in week 37, with the highest hospital admission rate for confirmed RSV noted in patients aged less than one years old (65.8 per 100,000). The hospitalisation rate for RSV peaked in week 38 and 39 in 2021 (4.5 per 100,000).

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 29 September 2022.