1. Situation report Europe and forward look to the autumn
The A(H1N1v) pandemic
Situation report Europe
and forward look to the autumn
Zsuzsanna Jakab, Director European Centre for Disease Prevention and Control
Swedish Presidency Workshop, Jönköping, July 2009

2. One possible European scenario — summer 2009
October
July
Outbreaks will occur at different dates in different countries – exactly when acceleration will take place unclear. The UK suggests we cannot assume it will be October or November – Dr Helen Shirley-Quirk will tell us more later.
September
August
August
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3. Idealised curve for planning Reality is never so smooth and simple
Initiation Acceleration Peak Declining
25%
aths
20%
15%
Proportion of total cases, consultations, hospitalisations or de
For planning purposes there are these four components of a pandemic wave – Initiation, Acceleration, Peak and Decline. After the decline there may be a second and even third wave before influenza settles back down to its seasonal pattern again. Even then the seasonal flu is usually worse than the years before the pandemic because the seasonal flu is invigorated with new genetic material. The same four phases actually apply to epidemics as well. However, no pandemic has ever behaved in quite so neat a way. Pandemics don’t follow set patterns and each is different.
10% 5% 0% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Week
Single wave profile showing proportion of new clinical cases, consultations, hospitalisations or deaths by week. Based on London, 2nd wave 1918.
Source: Department of Health, UK
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4. Actual and projected cases
Data as at on 29 June, 2009.
The projection given here will vary as data becomes available.
Slide supplied by Department of Health, UK

5. Proportion of total cases, consultations, hospitalisations or de
It will vary from place to place – and local can be more intense than national
25%
aths
20%
15%
Proportion of total cases, consultations, hospitalisations or de
Also there is a lot of local variation. This is an idealised smooth national curve with idealised local curves showing how the national curve can hides a series of short, sharp local epidemics. These can have higher peaks and this is why planning guidance for local areas often has higher planning assumptions (e.g. numbers of patients a hospital can expect to have to deal with) that is higher than what you might expect from national idealised curves.
10% 5% 0% 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Week
In reality, larger countries can experience a series of shorter but steeper local epidemics.
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6. Seasonal influenza compared to pandemic — proportions of types of cases
There will be pressure on the primary and secondary health services – especially paediatric and intensive care.
Deaths
Requiring hospitalisation
Clinical symptoms
But remember this is idealised – and in 2009 in North America this is not putting as many people into Hospital as you would expect from the above
Deaths
Requiring hospitalisation
Asymptomatic
Clinical symptoms
Asymptomatic
Seasonal influenza
Pandemic

7. 1918/1919 pandemic: A(H1N1) influenza deaths, England and Wales
2,000
4,000
6,000
8,000
10,000
12,000
14,000
16,000
18,000 27 29 31 33 35 37 39 41 43 45 47 49 51 2 4 6 8 10 12 14 16 18
1918
1919
Week no. and year
Deaths in England and Wales
Lets look at previous pandemics. This one is the worrying one Its important to emphasise that this and the other slides of 1957 and 1968 are from one country – the UK and ECDC is grateful to the Department of Health in London and UK’s Health Protection Agency for making the public data available to ECDC. There are data from other countries but the important point is that the pandemics varied a lot. They also varied in detail between European countries and even within countries.
The 1918/1919 pandemic is the worst ever seen. It is concerning for 2009 with the small herald wave in the late Spring and then the massive autumn wave. It has been estimated that if it happened again it would result in perhaps about a million additional deaths in the European Union area see next slide and Murray CJL Lopez AD, Chin B, Feehan D, Hill KH Estimation of potential global pandemic influenza mortality on the basis of vital registry data from the pandemic: a quantitative analysis, Lancet (2006); 368:
1918/19: ‘Influenza deaths’, England and Wales. The pandemic affected young adults, the very young and older age groups.
Transmissibility: estimated Basic Reproductive Number (Ro)
Ro = 2-3 (US) Mills, Robins, Lipsitch (Nature 2004)
Ro = (UK) Gani et al (EID 2005)
Ro = (UK) Hall et al (Epidemiol. Infect. 2006)
Ro = (Geneva) Chowell et al (Vaccine 2006)
Courtesy of the Health Protection Agency, UK