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ICU-HDU Influenza Surveillance

BAAS: R00304


Frequency: Weekly


Background to the collection


A national mandatory collection, the UK Severe Influenza Surveillance System (USISS) is operating to report the number of confirmed influenza cases admitted to Intensive Care Units (ICU) and High Dependency Units (HDU) and number of confirmed influenza deaths in ICU/HDU across England. A confirmed case is defined as an individual with a laboratory confirmed influenza infection admitted to ICU/HDU. Prior to the 2009 influenza pandemic there was a recognised gap in surveillance of severe respiratory infection in the UK, in particular with regards to hospitalised cases of influenza. A pilot surveillance scheme for severe influenza, the UK Severe Influenza Surveillance System (USISS), was initiated during the 2010/11 post-pandemic influenza season in order to monitor and estimate the impact of seasonal influenza on the population and to describe the epidemiology of severe disease. The system was subsequently rolled out in the 2011/12 influenza season and has continued to operate since and is mandated for all NHS trusts.

The objectives of the collection are as follows:

1) Monitor and estimate the impact of influenza (both seasonal and pandemic) on the population

2) Describe the epidemiology of severe influenza (ICU admissions and deaths) in time, place and person

3) Be able to rapidly identify and describe the epidemiological features of a novel influenza virus

4) To monitor the impact of the introduction of the childhood influenza vaccination programme.


Launch and submission dates:

WeekPeriodLaunch date Deadline date
w/c 2 October 20172Oct to 8 Oct 20179 October 201711October 2017
w/c 9 October 20179 Oct to 15 Oct 201716 October 201718 October 2017 
w/c 16 October 201716 Oct to 22 Oct 201723 October 201725 October 2017
w/c 23October 201723 Oct to 29 Oct 201730 October 20171 November 2017
w/c 30 October 201730 Oct to 5 Nov 20176 November 20178 November 2017
Continues to   
w/c 14 May 201814 May to 20 May 201821 May 201823 May 2018

All Deadlines are 11:00 a.m.

All collections will remain open for 2 weeks following the Deadline date for submission of amended data, if appropriate.

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