Influenza epidemics kill hundreds of thousands of people a year and cause millions cases of illness. It is a major public health concern and a major drain on economic productivity as sick employees take time off work. In the 50 years since the World Health Organization (WHO) instituted influenza surveillance, major strides have been made in combating influenza via surveillance of outbreaks in progress and preparation for upcoming influenza seasons.

However, in opening a meeting today of over 300 leading international experts at WHO headquarters to mark the 50^th anniversary of WHO influenza surveillance, WHO's Director-General emphasized that there is still much that can and should be done to reduce the toll that influenza exacts around the world.

The major challenges revolve around influenza vaccines, said Dr Gro Harlem Brundtland. They must be made more efficient, measures must be taken to ensure that they reach at-risk populations and, above all, the correct vaccines must be made available as universally as possible.

"Our goal is clear: to further reduce the mortality and morbidity related to influenza, particularly in those areas of our globe where resources are scarce. We have been able to achieve improvements in a constant effort over the last 50 years. Our target should now be to see these improvements in the prevention and control of influenza be made available throughout the globe in the course of the next century; a perspective imbedded in the long process of the strategy of Health for All," Dr Brundtland said.

The two-day meeting at WHO of international influenza experts is both looking forward at how to improve influenza prevention and control, and reviewing progress to date.

For the first time, WHO will distribute a "pandemic plan" which emphasizes the processes and issues appropriate for WHO and its Member States to consider when making preparations for an eventual influenza pandemic.

"Time to react may be very short – from the first recognition of a new subtype and the onset of a full-blown pandemic. It may be too short to prepare a vaccine and to use it. All the time gained from advance planning may be of critical value in managing the threat. WHO will maintain a Pandemic Task Force during inter-pandemic periods to initiate appropriate measures, whenever a possible pandemic virus is reported, as well as to monitor the level of preparedness believed to exist," said Dr Brundtland.

WHO's Global Surveillance Programme for Influenza already consists of 110 national influenza centres in 83 countries, plus four Collaborating Centres for Virus Reference and Research in Australia, Japan, the United Kingdom and the United States of America. This meeting's participants will work to strengthen global influenza surveillance by establishing national influenza centres in countries which still do not have one and by reinforcing existing surveillance centres which have weakened over time. The assembled experts will also work on means of stimulating research and dissemination of information on better ways to control and prevent influenza.

Influenza was first described by Hippocrates in 412 BC and influenza-like outbreaks have been clearly documented since 1173 AD. Since 1580, 31 such possible influenza pandemics – global epidemics - have been documented, with three occurring in this century: in 1918, 1957 and 1968. While pandemics can kill upwards of 20 million people (as was the case in the Spanish Flu Pandemic of 1918-1920), more people have died this century from influenza complications that have occurred during a seasonal epidemic, than from a pandemic.

Sometimes, pauses in the spread of a particular strain of influenza virus during a growing epidemic occur, and this provides time for progressive implementation of prevention activities as the pandemic proceeds.

For further information, journalists can contact Gregory Hartl, Office of Press and Public Relations, WHO, Geneva. Telephone (41 22) 791 44 58. Fax (41 22) 791 48 58. E-Mail: hartlg@who.int