Weekly pandemic flu media update

17 December 2009

KEY POINTS

• The consultation rate for flu-like illness in England from the Royal College of General Practitioners (RCGP) scheme has decreased slightly to 29.7 per 100,000 in week 50 compared to 33.1 in week 49. This is just below the English baseline threshold of 30/100,000.
• The estimated cases self referring to the National Pandemic Flu Service have shown decreases in all areas of assessments, authorisations and collections. This is across all regions and most age groups. 
• 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 19,000) which represents a small decrease from the previous week.    
  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 50 (ending 13 December) GP consultation rates for flu-like illness in England have shown a decrease compared to the previous week (33.1 per 100,000 in week 49 to 29.7per 100,000 in week 50) which is just below the English 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 of 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 showed a slight decrease from 38.6 per 100,000 in week 49 to 33.8 per 100,000 in week 50. The weekly rate for flu-like illness in all SHA regions show general decreasing trends in all SHAs except the East Midlands and South West and a decrease is also seen in all age groups. 

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 50 (ending 13 December)

The latest weekly flu-like illness rates show that the highest flu-like illness consultation rates were in the <1 and 1-4 year-old age bands. Compared with week 49, this week (week 50) rates have decreased in all age bands. The largest decrease (23%) is in the <1 year age band.

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 16 December 2009) 4,405 viruses have been analysed by the HPA Centre for Infections for the genetic marker commonly associated with resistance to oseltamivir in seasonal H1N1 flu (H274Y). 25 viruses have been found to carry this marker in the UK with three of these, through additional testing, showing evidence of resistance when viral growth is tested in the presence of oseltamivir. These viruses are still sensitive to zanamivir. In addition, 293 specimens have been fully tested for susceptibility to antivirals. 

Information on medical history was available for 17 cases, all of whom had an underlying medical condition: 14 were immunosuppressed and three had chronic respiratory or neurological illnesses.

Testing of samples, taken before and after treatment with oseltamivir, show that the antiviral resistance in 14 of the cases was treatment-induced, four are probably acquired through person to person transmission, and in four cases the origin of the resistant virus is still under investigation.

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: 523 patients (currently hospitalised as of 8am on 16 December).  The number of hospitalised patients is now declining.

Deaths - the number of deaths related to swine flu in England is 203 (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 16 December 2009)

Total deaths reported

11,188

In the last 7 days, the total number of deaths reported globally has increased by 11% on the previous 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 11 December that for:

• Tropical regions: Transmission of flu remains geographically widespread but overall disease activity has been declining in most areas.    
• Central and Western Asia: Spread of the swine flu virus remains active. Flu-like illness/Acute Respiratory Illness (ARI) activity continues to increase in Kazakhstan and Kyrgyzstan, but may have peaked in Afghanistan, Israel, and Oman. The pandemic flu virus continues to circulate in Iran, Iraq, Jordan, and in much of the surrounding region.
• North America and Europe: Pandemic flu activity has passed its peak in North America and in parts of western, northern, and eastern Europe, but activity continues to increase in parts of central and south-eastern Europe.
• Eastern and southern Asia: Transmission of flu remains variable in east Asia. Flu activity continues to increase in Japan and has recently begun to increase in Hong Kong SAR and Chinese Taipei, both of which previously experienced a peak of transmission. Elevated but stable flu-like activity has been reported in southern China, but declines in activity continue to be observed in northern China and Mongolia. In South Asia, flu activity has begun to increase in the north-western parts of India and in Sri Lanka. A small number of seasonal flu viruses continue to be detected in Asia but detections are beginning to decrease.
• Africa: Limited data suggest that the swine flu virus continues to be detected from all parts of the continent (except South Africa where the winter season has passed). Swine flu appears to be the predominant flu virus circulating in northern and eastern Africa.
• Temperate southern hemisphere region: Sporadic cases of swine flu have been reported in recent weeks but no sustained local transmission has been observed.

More information on the latest global situation can be found on the WHO website at: http://www.who.int/csr/don/2009_12_11a/en/index.html

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 December 2009