Weekly pandemic flu update

30 July 2009

KEY POINTS

• Weekly GP consultation rates show a plateau or small decrease over the last week in England.  This coincides with the start of school holidays and the introduction of the National Pandemic Flu Service.  
• There is no sign that the virus is changing. It is not becoming more severe or developing resistance to anti-virals. The small number of deaths has mainly been in older children and adults with underlying risk factors.
• Overall across the UK the indications are that the number of cases are no longer rising rapidly, and may have plateaued.  
• Producing reliable estimates at present is very challenging with the move from GP consultations to the National Pandemic Flu Service and issues such as the start of the school holidays. On an equivalent basis to previous weeks, HPA estimates that there were 110,000 new cases in England last week (range 60,000 - 160,000). There has been a decrease in the estimated number of cases in 5-14 year olds. Estimated cases have continued to increase in other age-groups and in the North. 

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, 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 30 (ending 26 July) there was a small decrease in GP consultation rates for flu-like illness in England compared to last week (155 per 100,000 to 138 per 100,000). The rate declined in all three RCGP regions (North, South and Central). There was a substantial reduction in children aged 5-14 years (290 to 182/100,000).

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 has levelled off this week compared to last, with a slight increase from 221 to 225.6/100,000. However, the daily flu-like illness rate for Tuesday 28 July was less than a third of that seen on Tuesday 21 July with lower rates of flu-like illness seen in all SHAs. The decline coincided with school closures on 18 July and the introduction of the National Pandemic Flu Service on 23 July. Observations over the next week will clarify trends.   

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 (02/06 to 28/07) all ages

Figure 4: QSurveillance® weekly influenza-like illness rate by age band (to week 30)

The greatest reduction was in 5-14 year olds. This coincided with the introduction of the National Pandemic Flu Service and school closures. The highest flu-like illness consultation rates were in the <1 and="and" 1-4="1-4" age="age" groups.</p="groups.</p" />

SYNDROMIC SURVEILLANCE

NHS Direct

On 23 July the National Pandemic Flu Service (NPFS) was implemented. This had an impact on the number of 'cold/flu' calls received through the routine NHS Direct service, with a fall in the proportion of 'cold/flu' calls. The fall continued over the weekend. 

Figure 5: Daily NHS Direct/HPA Syndromic Surveillance System estimated total cold/flu calls 2009 compared to routine daily NHS Direct 'cold/flu' calls 2008-2009 shown as a percentage of all NHS Direct calls

VIRAL CHARACTERISTICS

Viral characteristics (including antiviral susceptibility (as at 28/07/09): Testing for antiviral susceptibility is carried out by the Agency's Respiratory Virus Unit, Centre for Infections, in Colindale. 517 viruses were analysed for the marker commonly associated with resistance to oseltamivir in seasonal influenza (H274Y); none were found to carry this marker. In addition, 80 specimens were 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: 793 patients (hospitalised as of 8am on 28 July)

Deaths - the number of deaths related to swine flu in England is 27. (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 28 July 2009)

Grand total of cases confirmed: 168,895
Total of deaths reported: 1,012
Table 1: Countries with more than 1000 laboratory-confirmed cases reported, as at 28 July (in addition to UK).

Country	Cases		Deaths
	Cumulative total	% increase in last 7 days	Cumulative total
Northern Hemisphere
Canada	10449	3%	55
China (Hong Kong)	3081	57%	1
China (mainland)	1852	20%	0
Germany	3349	115%	0
Israel	1520	39%	1
Japan	5022	17%	0
Malaysia	1219	46%	3
Mexico	15727	11%	141
Philippines*	2668		3
Singapore*	1217		5
South Korea	1279	185%	0
Spain	1538	17%	6
Taiwan	1280	1276%	0
Thailand	6776	32%	24
USA**	43771	8%	302
Southern Hemisphere
Argentina	3056	0%	165
Australia	19026	36%	50
Brazil	1566	4%	34
Chile	11641	7%	79
New Zealand	2704	9%	13
Peru	3292	23%	23

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: 3 June 2010