This is the fifth monthly report of the 2012/13 influenza season. For this season, we will provide detailed influenza update reports on a monthly basis with bulletin style weekly updates in the weeks in between.
This report contains summary epidemiological information on influenza-like illness (ILI) and acute respiratory illness (ARI) activity, its severity and impact in the community and secondary care settings, and estimation of vaccine uptake.
The GP consultation rate for influenza-like illness (ILI) has been calculated using the same method as in the season 2011/2012. Please refer to the technical document for further information.
Clinical influenza activity remained largely stable over the last four weeks and remained below the threshold for normal seasonal activity overall. Virological influenza activity detected through the GP sentinel and non-sentinel sources fluctuated over the last four weeks. In week 7, activity detected through the GP sentinel increased compared to the previous week, whereas virological activity detected through non-sentinel sources remained stable.
Six influenza cases with severe infection requiring management in an intensive care unit (ICU) were reported to HPS in the last week (3 A(H3), 2 A(H1N1)2009, 1 A (subtype unknown)). Since week 40 2012, a total of 71 influenza infections requiring ICU have been reported to HPS, 20 of whom are known to have died.
Levels of non-influenza seasonal respiratory pathogens overall were in line with expected levels over the last four weeks, with the exception of the level of para-influenza virus and rhinovirus reports. Levels of rhinovirus infections and para-influenza infections (non-sentinel sources) increased to levels slightly higher than at the same time last year but have decreased to within expected levels for week 7.
There is continuing evidence of significant community circulation of influenza. A CMO letter recommending that antivirals can be used in primary care where clinically appropriate was issued on the 20 December and can be accessed at: http://www.sehd.scot.nhs.uk/cmo/CMO(2012)10.pdf.