Weekly pandemic flu update
23 July 2009
KEY POINTS
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GP consultation rates have risen sharply over the last week in England.
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The under-5s and 5-14 year olds are the age groups predominantly affected, with the over 65s continuing to show much lower rates.
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The majority of cases continue to be mild. The provisional number of deaths related to swine flu is 26.
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HPA estimates that there were 100,000 new cases of swine flu in England last week (range 60,000 - 140,000).
This estimate is based on latest weekly consultation rates for flu-like illness, taking into consideration positivity rates for swine flu H1N1 from HPA's virological sampling and a range of assumptions related to the numbers of people attending their GP.
Following the move from laboratory testing for confirmation of swine flu (H1N1v) to clinical diagnosis of cases, the level of flu in the community is being monitored using a range of surveillance mechanisms. These enable HPA to accurately estimate flu levels, monitor new and emerging viruses and identify trends in activity. Our experience over many flu seasons means we can confidently continue to monitor the incidence and distribution of this pandemic virus over the summer and beyond.
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 29 (ending 19 July), GP consultation rates for flu-like illness continued to increase sharply in England. The consultation rate is 155 per 100,000 compared with 73.4 per 100,000 in the previous week. Three English areas (North 126, Central 172 and South 155) show less differences in rates than previously observed.
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).
For QSurveillance® the flu-like illness weekly consultation rate reached 221.4 per 100,000 in week 29 compared to 86.8 in week 28. This is five times higher than the peak activity in winter 08/09 and high rates has been seen in all SHAs.
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 for week 29 (week ending 19 July) in UK (all ages).
Figure 3: QSurveillance® - flu-like illness weekly consultation rate for week 29 (week ending 19 July) by age band
The ILI consultation rates for every age group have increased significantly in week 29. The highest ILI rates remain in the 1-4 year olds (541/100,000 compared to 174/100,000 in week 28)
SYNDROMIC SURVEILLANCE
NHS Direct
Although an overall decrease has been seen in the most recent week, there continues to be a substantially higher proportion of calls to NHS Direct across most of England compared with seasonal data from previous winters.
Figure 4: Daily NHS Direct/HPA Syndromic Surveillance System estimated total 'cold/flu' calls by SHA (comparative data provided*)
* Based on between 8,000 and 30,000 calls each day to NHS Direct in April, May, June and July 2009. In recent winter flu seasons, the maximum proportion of calls to NHS Direct for 'cold/flu' has been 2.8%.
VIRAL CHARACTERISTICS
Antiviral susceptibility (as at 22/07/09): 60 of the swine flu (H1N1v) isolates have been fully tested for susceptibility by the Health Protection Agency. All 60 were found to be sensitive to oseltamivir and zanamivir. 368 positive specimens have also been analysed for the marker commonly associated with resistance to oseltamivir in seasonal influenza (H274Y), all were found not to carry this marker.
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: 840 patients
Deaths – The provisional number of deaths related to swine flu is 26. The figure is the same as last week because some unrelated deaths have been removed and others added. (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
Total of Confirmed Cases reported by European Centre for Disease Prevention and Control (ECDC) (Update 17:00 CEST 21 July 2009)
|
Grand total of cases confirmed |
143,841 |
Total of deaths reported |
813 |
Table 1: Countries with more than 1000 laboratory-confirmed cases reported, as at 21 July (in addition to UK).
|
|
Cumulative total |
% increase in last 7 days |
Cumulative total |
|---|---|---|---|
|
Canada |
10156 |
5% |
45 |
|
China (Hong Kong) |
1964 |
48% |
1 |
|
China (mainland) |
1537 |
13% |
0 |
|
Germany |
1555 |
104% |
0 |
|
Israel |
1094 |
51% |
0 |
|
Japan |
4275 |
47% |
0 |
|
Mexico |
14229 |
22% |
128 |
|
Philippines* |
2668 |
|
3 |
|
Singapore* |
1217 |
|
1 |
|
Spain |
1309 |
27% |
4 |
|
Thailand |
5120 |
111% |
24 |
|
USA |
40617 |
9% |
263 |
|
Southern Hemisphere |
|
||
|
Argentina |
3056 |
4% |
137 |
|
Australia |
14037 |
55% |
37 |
|
Brazil |
1175 |
14% |
4 |
|
Chile |
10926 |
14% |
40 |
|
New Zealand† |
2477 |
39% |
11 |
|
Peru |
2671 |
40% |
12 |
*:no case update available since last week.
†: Data from New Zealand Ministry of Health as was not included in ECDC report
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 6647
020 8327 7098
020 8327 7097
020 8327 6690
Last reviewed: 23 July 2009
