Official Statistics

National flu report summary: 20 December 2018 (week 51)

Updated 26 September 2019

Main points: data up to week 50, 2018

Data up to week 50 (ending 16 December 2018) shows:

• influenza activity continues to increase, with sporadic cases of influenza detected in the community though all indicators remain below baseline threshold levels
• the impact of flu on healthcare services is below baseline threshold levels for hospitalisations and at low intensity levels for ICU and HDU admissions
• influenza A(H1N1)pdm09 is the dominant subtype

The full weekly flu report this summary is based on, accompanying spreadsheet of data and slideset are available from weekly national flu reports: 2018 to 2019 season.

Surveillance scheme summaries

Community

Twenty-eight new acute respiratory outbreaks have been reported in the past 7 days. Seventeen outbreaks were reported from care homes where 1 tested positive for influenza A (not subtyped) and 1 was positive for RSV. Four outbreaks were reported from hospitals where 3 tested positive for influenza A (not subtyped) and 1 tested positive for RSV. Seven outbreaks were reported from schools where 1 tested positive for influenza A (not subtyped).

Primary care

Data from primary care surveillance shows:

• the rate of influenza-like illness (ILI) was below baseline threshold levels
• the overall weekly ILI GP consultation rate was 8.1 per 100,000 registered population in participating GP practices for England, this is an increase from 7.6 per 100,000 in week 49
• in the devolved administrations, ILI rates were also below baseline threshold levels

Secondary care

Data from secondary care surveillance shows:

• hospitalisation rate observed was below baseline threshold levels, with a rate of 0.82 per 100,000 trust catchment population for England (21 NHS Trusts), this is an increase from 0.52 per 100,000 in week 49
• ICU and HDU admission rate observed was at low intensity threshold levels, with a rate of 0.09 per 100,000 trust catchment population for England (131 out of 143 NHS Trusts), this is an increase from 0.07 per 100,000 in week 49
• there was 1 new influenza admission (1 influenza A(H1N1)pdm09) reported from the 6 severe respiratory failure centres in the UK

All-cause mortality

Data from all-cause mortality surveillance shows:

• no statistically significant excess all-cause mortality by week of death was seen overall and by age group in England
• in the devolved administrations, no statistically significant excess all-cause mortality for all ages was observed in Scotland, Northern Ireland and Wales

Microbiological surveillance

Data from microbiological surveillance shows:

• in primary care 5 samples tested positive for influenza (4 influenza A(H1N1)pdm09 and 1 influenza A (unknown subtype)) with a positivity of 10.2% through the UK GP sentinel schemes
• in secondary care influenza percent positivity was 7.0%, below baseline threshold levels, this is an increase from 5.5% in week 49
• a total of 135 detections were recorded through the DataMart scheme (79 influenza A(H1N1)pdm09, 15 influenza A(H3), 38 influenza A(unknown subtype) and 3 influenza B)
• RSV positivity decreased to 15.5% with the highest positivity amongst children aged 5 years and younger also decreasing to 31.0%

Vaccination

Data from the GP patient, healthcare worker and primary school-age children flu vaccine uptake programmes shows:

• up to week 50 2018, in 96.7% of GP practices in England, the provisional proportion of people who had received the 2018 to 2019 influenza vaccine in targeted groups was 43.4% in under 65 years in a clinical risk group, 42.8% in pregnant women and 68.6% in people aged 65 years and over
• in 97.1% of GP practices reporting for the childhood collection the provisional proportion vaccinated was: 40.5% in 2 year olds and 41.7% in 3 year olds
• provisional data from the first monthly collection of influenza vaccine uptake by frontline healthcare workers show 61.0% were vaccinated by 30 November 2018, compared to 59.3% vaccinated in the previous season by 30 November 2017
• provisional data from the first monthly collection of influenza vaccine uptake for children of school years reception to year 5 shows 20.5% in school year reception age, 20.7% in school year 1 age, 19.9% in school year 2 age, 19.7% in school year 3 age, 18.9% in school year 4 age and 18.2% in school year 5 age were vaccinated by 31 October 2018

International situation

• in the temperate zone of the Northern Hemisphere, influenza activity started to increase although overall influenza activity remained low. Increased influenza was reported in some countries of Southern and South-East Asia
• in the temperate zone of the Southern Hemisphere, influenza activity returned to inter-seasonal levels
• worldwide, seasonal influenza subtype A viruses accounted for the majority of detections

Further information

The full weekly flu report this summary is based on, accompanying spreadsheet of data and slideset are available from weekly national flu reports: 2018 to 2019 season.

See seasonal influenza: guidance, data and analysis for further information on the symptoms, diagnosis, management, surveillance and epidemiology of seasonal influenza (flu).

See sources of UK flu data: influenza surveillance in the UK for further information and guidance on the surveillance schemes we use to track seasonal influenza.