Weekly pandemic flu media update

15 October 2009

KEY POINTS

• The flu-like illness rate in England from the Royal College of General Practitioners (RCGP) scheme increased to 29.1 per 100,000 in week 41. An increase was seen in most age groups except those over 65 years.
• The main burden of flu-like illness nationally is in the 5-14 and 15-24 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 over 65s. The largest increase (17%) in 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 27,000 new cases in England last week (range 13,000 to 58,000) compared with 18,000 in week 40.  This indicates a doubling every two weeks.  
  This estimate incorporates data from National Pandemic Flu Service and GP consultations.
• During week 39 (September 27-October 3) flu activity increase sharply in the US.
  

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 41 (ending 11 October) GP consultation rates for flu-like illness in England increased compared to the previous week (26.3 per 100,000 in week 40 to 29.1 per 100,000 in week 41). This is still just below 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 increased from 28.6 per 100,000 in week 40 to 32.0 per 100,000 in week 41. The daily rate for flu-like illness have showed an increased level of flu-like illness activity.  The daily rates in all age groups in the last week have risen though the rates in the 65-74 and over 75s remain low.

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® - daily consultation rate for influenza-like illness by English SHA (all ages)

Figure 4: QSurveillance influenza-like illness rate by age band in week 41 (ending 11 October)

The latest weekly flu-like illness rates show that the highest flu-like illness consultation rates were in the 5-14 and 15-24 year-old age groups. Compared with week 40 this week (week 41) rates have increased in all age groups, particularly in the <1 (29.4="(29.4" 36.6)="36.6)" and="and" 15-24="15-24" year-olds="year-olds" (39.8="(39.8" to="to" 47.7="47.7" per="per" 100,000).="100,000)." </p="</p" />

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 14 October 2009) 1,468 viruses have been analysed by the Centre for Infections for the genetic marker commonly associated with resistance to oseltamivir in seasonal H1N1 flu (H274Y). Two viruses have been found to carry this marker in the UK. In addition, 285 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.

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: 363 patients (currently hospitalised as of 8am on 14 October). 

Deaths - the number of deaths related to swine flu in England is 83 (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 14 October 2009)

Total deaths reported: 4,703

In the last 7 days, the total number of deaths reported globally has increased by 4% - same increase as 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 9 October that for:

• Tropical regions: influenza activity remains variable.
• Temperate southern hemisphere regions: influenza transmission has largely returned to baseline (Chile, Argentina, and New Zealand) or has declined substantially (Australia and South Africa).
• Temperate northern hemisphere regions: influenza virus transmission and rates of influenza-like-illness (ILI) continue to increase, reflecting an unusually early start to the fall and winter influenza season in many countries.

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