Weekly pandemic flu media update

24 September 2009

KEY POINTS

• The rates of flu-like illness and related activity have shown further increases in England.
• The flu-like illness rate in England from the Royal College of General Practitioners (RCGP) scheme increased to 16.2 per 100,000 in week 38. Most age groups saw an increase.
• 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 under 65. Once again, the biggest increase has been seen in the 5-15 year old age group with antiviral collections again doubling from 2,886 to 5,580.
• 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 9,000 new cases in England last week (range 5,000 to 20,000).  This is the second weekly increase since week 30.
  This estimate incorporates data from National Pandemic Flu Service and GP consultations.
• Sharp rises in influenza activity in recent weeks are reported from the USA - concentrated particularly in school age children. Increasing activity has also been reported in a number of European countries, particularly France.
  

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 38 (ending 20 September) GP consultation rates for flu-like illness in England increased compared to the previous week (12.9 per 100,000 to 16.2 per 100,000). Most age groups saw an increase but remain below baseline threshold in England.

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 14.5 per 100,000 in week 37 to 17.3 per 100,000 in week 38. The daily rate for flu-like illness have showed an increased level of ILI activity. 

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 38 (ending 20 September)

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 followed by the <1 year age group. Compared to week 37 this week (week 38) has continued to see an overall increase, especially in the <24 year age population. 

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 23 September 2009) 973 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, 254 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: 218 patients (currently hospitalised as of 8am on 23 September). These have increased in all age groups under 65 years.

Deaths - the number of deaths related to swine flu in England is 70 (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 22 September 2009)

Total deaths reported

4,144

In the last 7 days, the total number of deaths reported globally has increased by 12% - a slightly higher increase compared to the 6% 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 18 September that for:

• Tropical regions: influenza transmission remains active in tropical regions of Asia and the Americas. Regional to widespread influenza activity continues to be reported throughout much of South and Southeast Asia, with increasing trends in respiratory diseases being reported in India and Bangladesh. Regional to widespread influenza activity continues to be reported for tropical regions of Central and South America without a consistent pattern in the trend of respiratory diseases, although continued increases are being reported in Bolivia and Venezuela.
• Temperate southern hemisphere regions: (represented by countries such as Chile, Argentina, Australia, New Zealand, and South Africa); influenza activity continues to decrease or return to baseline.
• Temperate northern hemisphere regions: activity is variable. In the United States, regional increases in influenza activity are being reported (particularly in the southern, south eastern and north eastern states). Most of Europe and Central Asia is reporting low respiratory disease activity, although France has reported increases in activity above the seasonal epidemic threshold and geographically localised influenza activity is being reported in several countries (Austria, Georgia, Ireland, Luxembourg, Norway, Portugal, the Czech Republic, Cyprus, and Israel). In Canada, influenza activity remains low. In Japan, influenza activity increased above the seasonal epidemic threshold with the most notable increases being reported on the southern island of Okinawa.

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: 24 September 2009