Weekly pandemic flu media update

22 October 2009

KEY POINTS

• The flu-like illness rate in England from the Royal College of General Practitioners (RCGP) scheme increased to 39.1 per 100,000 in week 42 compared to 29.1 in week 41. An increase was seen in all age groups.
• The main burden of flu-like illness nationally is in the 1-4 and 5-14 years age groups.
• This week, the antiviral collection numbers in the National Pandemic Flu Service have continued to increase and this has been seen in all age groups except the 75+. The largest increase (40%) in week 42, compared with week 41, was seen in the 5-14 year olds.
• Interpretation of data to produce estimates on the number of new cases continues to be subject to a considerable amount of uncertainty. HPA modelling gives an estimate of 53,000 new cases in England last week (range 27,000 to 115,000) compared with 27,000 in week 41.  This is a 96% increase.
  This estimate incorporates data from National Pandemic Flu Service and GP consultations.
  

Following the move from laboratory testing for confirmation of swine flu to clinical diagnosis of cases, the level of flu in the community is being monitored using a range of surveillance mechanisms, including the RCGP consultation rates, QSurveillance®, and the National Pandemic Flu Service.

A more detailed UK weekly epidemiology update can be accessed at:
www.hpa.org.uk/swineflu/surveillance&epidemiology

CLINICAL INDICATORS
Clinical data are obtained from GP surgeries that report the weekly and daily consultations for flu-like illness and other acute respiratory illness.

Current estimated weekly Royal College of General Practitioners (RCGP) consultation rates of flu-like illness

From a network of approximately 100 general practices covering a population of approximately 900,000 with an equal distribution within each of three defined reporting regions; North, Central and South.

In week 42 (ending 18 October) GP consultation rates for flu-like illness in England increased compared to the previous week (29.1 per 100,000 in week 41 to 39.1 per 100,000 in week 42). This is now above the baseline threshold of 30/100,000.

Figure 1: Current estimated weekly RCGP consultation rates of flu-like illness

QSurveillance®
Set up by the University of Nottingham and EMIS (the main supplier of general practice computer systems within the UK) in collaboration with the Health Protection Agency. QSurveillance® is a not-for-profit network over 3,300 general practices covering a total population of almost 22 million patients (> 25% of the UK population).

The weekly QSurveillance® flu-like illness consultation rate continued to show a gradual rise from 32.0 per 100,000 in week 41 to 37.4 per 100,000 in week 42. The weekly rate for flu-like illness in all SHA regions have showed a small rise in levels of flu-like illness activity except the North East where there was a marked increase compared with week 41.  The weekly rates in all age groups are also showing a slow increasing trend with 5-14 year-olds showing the largest rise.

NB: QSurveillance® is based on data from 43% of England's population (about 3000 practices), 10% of the population in Wales, 17% in Northern Ireland, and 0% in Scotland.

Figure 2: QSurveillance® - weekly consultation rate for flu-like illness in England, Wales and Northern Ireland (all ages)

Figure 3: QSurveillance® - weekly consultation rate for influenza-like illness by English SHA (all ages) 

Figure 4: QSurveillance influenza-like illness rate by age band in week 42 (ending 18 October)

The latest weekly flu-like illness rates show that the highest flu-like illness consultation rates were in the 1-4 and 5-14 year-old age groups. Compared with week 41 this week (week 42) rates have increased in all age groups, particularly in the 1-4 (43 to 54 per 100,000) and 5-14 year olds (49 to 70)

SYNDROMIC SURVEILLANCE

NHS Direct
On 23 July the National Pandemic Flu Service was implemented. This had an impact on the number of 'cold/flu' calls received through the routine NHS Direct service. For this reason, data from NHS Direct do not reflect the true pattern of cold/ flu callers and so are not currently an accurate surveillance tool.

VIRAL CHARACTERISTICS

To date (as of 21 October 2009) 1,733 viruses have been analysed by the Centre for Infections for the genetic marker commonly associated with resistance to oseltamivir in seasonal H1N1 flu (H274Y). Three viruses have been found to carry this marker in the UK. In addition, 292 specimens have been fully tested for susceptibility. 

The Agency is continually assessing its advice to government on health protection policies such as antiviral use. Currently there is no requirement to change existing guidance.

There have been no significant changes in the virus.

SEVERITY
Disease severity continues to be monitored. The disease is generally mild in most people so far, but is proving severe in a small minority of cases.

Swine flu hospitalisations in England: 506 patients (currently hospitalised as of 8am on 21 October). 

Deaths - the number of deaths related to swine flu in England is 93 (This figure represents the number of deaths in individuals with swine flu but does not represent the number of deaths that can be attributed to swine flu).

INTERNATIONAL SUMMARY

Confirmed global deaths reported by ECDC (Update 17:00 CEST 21 October 2009)

Total deaths reported: 5,303

In the last 7 days, the total number of deaths reported globally has increased by 13% - up from the 4% increase reported last week.

NB: Laboratory confirmed case numbers are no longer being reported for most countries as they do not give a representative view of the actual number of cases worldwide.

The World Health Organization (WHO) reported on 16 October that for:

• Tropical regions: influenza activity remains variable.
• Temperate southern hemisphere regions: influenza transmission has returned to below baseline levels in all countries, and very few detections of pandemic H1N1 2009 virus are being reported..
• Temperate northern hemisphere regions: influenza virus transmission and rates of influenza-like-illness (ILI) continue to increase.  In China, nearly half of influenza viruses detected are the co-circulating seasonal influenza A (H3N2) viruses.

This update summarises information published by WHO about the latest global situation and is also published on the HPA website at http://www.hpa.org.uk/HPA/Topics/InfectiousDiseases/InfectionsAZ/1251473469008/

ENDS

Notes to editors
General infection control practices and good respiratory hand hygiene can help to reduce transmission of all viruses, including swine flu. This includes:

• Maintaining good basic hygiene, for example washing hands frequently with soap and water to reduce the spread of virus from your hands to face or to other people.
• Cleaning hard surfaces (e.g. door handles) frequently using a normal cleaning product.
• Covering your nose and mouth when coughing or sneezing, using a tissue when possible.
• Disposing of dirty tissues promptly and carefully.
• Making sure your children follow this advice. 

Further information on swine flu is available on the Health Protection Agency's website at www.hpa.org.uk/swineflu.

For media enquiries only please contact the Health Protection Agency's Centre for Infections press office on:  

020 8327 7080   
020 8327 7097  
020 8327 7098
020 8327 6690  
020 8327 6647

Last reviewed: 19 May 2010