Weekly pandemic flu media update

3 September 2009

KEY POINTS

• This week there has been a further reduction in the rates of flu-like illness and related activity.
• Weekly GP consultation rates continued to decrease over the last week in England.
• The majority of cases continue to be mild. There is no sign that the virus is changing. It is not becoming more severe or developing resistance to anti-virals.
• 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 4,500 new cases in England last week (range 2,500 to 10,000). There has been a decrease in estimated number of cases in all age groups and in all regions.
  This estimate incorporates data from National Pandemic Flu Service and GP consultations.

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

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

VIRAL CHARACTERISTICS

Viral characteristics (including antiviral susceptibility (as at 26/08/09): Testing for antiviral susceptibility is carried out by the Agency's Respiratory Virus Unit, Centre for Infections, in Colindale. 786 viruses have been analysed for the marker commonly associated with resistance to oseltamivir in seasonal influenza (H274Y); none were found to carry this marker. In addition, 252 specimens have been fully tested for susceptibility; all were found to be sensitive to oseltamivir and zanamivir.

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: 159 patients (currently hospitalised as of 8am on 02 September).

Deaths - the number of deaths related to swine flu in England is 61. (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 01 September 2009)

Total deaths reported

2,594

In the last 7 days, the number of deaths reported globally has increased by 13%. This compares to a 21% increase in 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.

General trends
Most southern hemisphere countries (represented by Chile, Argentina, New Zealand, and Australia) appear to have passed their peak of influenza activity and have either returned to baseline levels or are experiencing focal activity in later affected areas; while a few others (represented by South Africa and Bolivia) continue to experience high levels of influenza activity. Many countries in Central America and tropical regions of Asia continue to see increasing or sustained high levels of influenza activity with some countries reporting moderate strains on the healthcare system. In temperate areas of the northern hemisphere (North America, Europe, and Central Asia), influenza and respiratory disease activity remains low overall, with some countries experiencing localised outbreaks.
Source: WHO Disease Outbreak News
http://www.who.int/csr/don/2009_08_28/en/index.html

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.