Seasonal Influenza On Increase In Europe

It is official - this year's influenza season has begun, the European Influenza Surveillance Scheme (EISS) confirmed today. There is currently increased influenza activity reported in five countries: Greece, the Netherlands, Northern Ireland, Spain and Switzerland, and this has been accompanied by increases in laboratory confirmed influenza cases. This increase in activity signals the start of the influenza season and, based on historical data, influenza activity is expected to increase in many more countries over the coming weeks.

В  Laboratory confirmed cases from population based samples for Europe as a whole have risen from less than 100 per week up to week 50/2006 to over 350 in week 2/2007, and are expected to peak at between 1,000 and 2,000 as influenza affects more countries. The majority of influenza virus detections in Europe were reported from England, France, Greece, Norway, Scotland, Spain, Sweden and Switzerland, and in most other countries across Europe influenza viruses have been detected in low numbers.

В  Professor Koos van der Velden, Chairman of EISS, says, "Influenza strikes and spreads quickly, so rapid action is vital. The key to a quick response is accurate and timely surveillance. Data from the EISS network enable us to track influenza across Europe, including the pattern and speed of its spread and the predominant virus strain. We can then alert health care professionals and patients to facilitate rapid diagnosis and treatment and minimise the potential impact of the season."

В  This year's (2006-2007) season starts about two weeks earlier than last year's (2005-2006), which had high levels of influenza virus detections in Europe from mid-February to late April[1].В  And, unlike last year when influenza B was the dominant virus in Europe, this year's cases to date have primarily been of the H3 strain of the more virulent influenza A virus. Studies have shown that there is significantly higher mortality associated with the influenza A H3 virus compared to the influenza B virus[i].

В  Influenza is highly contagious and spreads rapidly by coughs and sneezes from people who are already carrying the virus[ii].В  Influenza affects approximately one in 10 people around the world every year[iii], creating substantial demands on healthcare resources and escalating costs due to increases in primary care consultations, hospitalisations, clinical complications, drug treatment and absence from work[iv],[v],[vi],[vii]. During an annual season, or epidemic, the number of deaths from influenza and its complications can be as high 500,000 people around the world every year[viii].

В  The EISS network receives data from 30 member countries in Europe tracking clinical activity, geographical spread and virus types. This information is reported in a weekly surveillance report available via the website and is uploaded to an influenza map on the home page. National data is available for all those countries who have reported weekly updates. The supply of timely surveillance information is critical to enable health authorities and health care professionals to respond appropriately.

В  "It's all very well having public health systems in place, whether for seasonal or pandemic influenza, but their effectiveness rests on having timely information and the ability to rapidly set the plan in motion when required.В  We urge health care providers to take advantage of our extensive resources and ensure they underpin their influenza systems with the most up-to-the-minute tracking data available", said Professor van der Velden.

В  The effects of influenza are debilitating, putting people out of action altogether, and recovery can take up to two weeks.В  Anyone can get the flu and it can be especially serious for the elderly, children and people with certain medical conditions (commonly defined as high-risk people).В  The most common symptoms of influenza include an abrupt onset of fever, headache, muscle ache and a dry cough1.В 

В  To reduce the risk of infection, particularly high-risk people should get an influenza vaccine as early as possible in the season.В  Now that the season has begun, the public should take general health precautions and, where possible, those infected with influenza should try to avoid close contact with others. To help prevent infection or reduce the severity and duration of infection, antiviral medications are available on prescription and are most effective the earlier they are taken in the course of the illness.В 

В  "Speed is the key to all influenza management", says Professor van der Velden, "Acting swiftly is crucial, both for health authorities and the general public.В  Flu is fast, so to beat it we need to be very quick too."

This article is supported by Roche for the advancement and support of medical, scientific and patient initiatives.

В  About influenza

Influenza, commonly called "the flu", is an acute respiratory illness that affects the upper and/or lower parts of the respiratory tract and is caused by an influenza virus. В There are three types of influenza viruses: A, B, and C[ix]. Influenza A subtypes and B viruses are classified by 'strains', variations of the virus caused by ongoing mutation.В  When a new strain of human influenza virus emerges, antibody protection that may have developed after infection or vaccination with an older strain may not provide protection against the new strain[x].В  Seasonal influenza usually occurs in the autumn and winter months, and usually peaks between December and March in the Northern hemisphere[xi].

В  About EISS

The European Influenza Surveillance Scheme (EISS), established in 1996, is a modern and efficient European surveillance system that collects high quality data, combining both epidemiological and virological information.В  The mission of EISS is to contribute to a reduction in morbidity and mortality from influenza in Europe.В 

В  The spread of influenza virus strains and their impact in Europe are monitored by EISS in collaboration with the WHO Collaborating Centre in London (United Kingdom) and the European Centre for Disease Prevention and Control in Stockholm (Sweden).В 

-- Graph showing how this year's influenza season compares with last year's

The key services managed by EISS include:

-- Weekly surveillance reports from all 30 member countries (26 EU member states, Norway, Switzerland, Serbia and the Ukraine), reported by over 13,500 sentinel physicians and 38 national reference laboratories, covering a total population of over 480 million inhabitants.

-- Influenza surveillance maps of Europe.В  (NB. Clicking on the map of a specific country will also link to the website of the national surveillance authority).

-- A weekly surveillance report, posted on the website and distributed at 12pm every Friday to subscribers, featuring the latest information on:
- Consultation rates
- Geographical spread intensity
- Historical time trends
- Virus types and dominant strains

-- A database of research mapping the trends of influenza over the past 10 years, available via the website. Data includes maps and graphical representations of all reporting countries.

В  Please visit the EISS website at http://www.eiss.org for further information.

References

i - Thompson et al JAMA January 8 Vol 289(2):179-186. Mortality associated with influenza and respiratory syncytial virus in the US.

ii - Department of Health, Centres for Disease Control and Prevention, Flu Facts, 2006.

iii - European Influenza Surveillance Scheme, Influenza Factsheet.В  Accessed 11 January 2007

iv - Meier CR, Napalkov PN et al. Population based study on incidence risk factors, clinical complications and drug utilisation associated with influenza in the United Kingdom. European J Clinical Microbiological Infectious Disease 2000; 19: 834-842

v - Fleming DM. The impact of three influenza epidemics on primary care in England and Wales, PharmacoEconomics 1996; 9 (suppl.3)

vi - Barker. WHO, impact of epidemic type A influenza in a defined adult population. American Journal of Epidemiology 1980; 112 (6)

vii - Keech M et al. The impact of influenza and influenza like illness on productivity and healthcare resource utilization in a working population. Occup Med (Lond). 1998;48(2):85-90

viii - WHO Factsheet 211. Revised March 2003. Accessed 11 January 2007

ix - Department of Health 'Immunisation Against Infectious Disease (The Green Book), Third edition'.В  В Chapter 19: Influenza. В London. The Stationery Office December 2006 link here (pdf)

x - Centers for Disease Control and Prevention, Influenza (flu)

xi - Health Protection Agency 'Frequently asked questions on influenza' Reviewed on 12 December 2005