A third of world population could get swine flu: WHO

GENEVA (AFP) - The World Health Organisation on Thursday said that in a pandemic situation it was reasonable to estimate that a third of the worlds population would catch the swine flu virus.
If you look at past pandemics, it would be a reasonable estimate that a third of the population would be infected if the current swine flu outbreak became a pandemic, said Keiji Fukuda, acting assistant director general of the UN health agency.
Fukuda had made the point in response to mounting concerns that the WHO may have over reacted given that most swine flu cases have turned out to be mild.
The WHO had raised its pandemic alert level to five out of six last week, signalling that a pandemic was imminent after the flu appeared to be spreading locally not just in Mexico but also in the United States.
The move prompted countries to activate their pandemic alertness plans.
Fukuda said when considering how to deal with such outbreaks, the WHO has to take into account the fact that in a full-blown pandemic, even if only a small percentage of people were to develop serious illness or die from the disease, it would translate into a large absolute number of people.
Fukuda stressed however that his estimate was based on past pandemics and that we live in a different world.
He added that very premature to forecast how many could die from a pandemic as it remained unclear what proportion of infected people were getting seriously ill or dying from the influenza A(H1N1) virus.
The UN health agency had estimated in a background document before this outbreak was known that a pandemic could lead to the deaths of between two to 7.4 million people around the world.
Fukuda said the situation surrounding the disease was still evolving. The virus could yet mutate into more dangerous forms. One of the absolute statements that you can make about influenza viruses is that they change, he said.
With the southern hemisphere heading into winter, it was also uncertain if the virus would take hold in that region where there were more developing countries than richer countries as in the northern hemisphere, he added.
We also have a population which are more vulnerable... this may be because of malnourishment, this may be because of war, this may be because of conditions like HIV infections, he said.
He noted that in past instances, such flu outbreaks may turn out to have a relatively mild impact on the developed world, but turn out to have a quite severe impact on the developing world.
Earlier Thursday, Fukuda told 13 Asian nations meeting in Bangkok to remain vigilant against the disease even if it now appears to be milder than what caused earlier pandemics such as the 1918 Spanish flu which killed at least 40 million people.
The WHO said 2,099 people have been confirmed to have contracted influenza A(H1N1), with 44 having died from the disease.
The warning came as officials from China, Japan, South Korea and the 10-member Association of Southeast Asian Nations (ASEAN) met in Bangkok to forge a common front in the fight against the influenza A(H1N1) virus.
Hundreds of Thai soldiers surrounded the venue for the meeting at a downtown Bangkok hotel to prevent a repeat of anti-government protests that wrecked a regional summit in Thailand in April.
It is critical for countries to maintain their alertness and monitoring so this evolution can be followed as closely as possible, Fukuda told the Asian officials via videolink from Geneva.
We dont believe we have fully got a handle on the severity of the phenomenon, he said, adding that Asian nations should look very closely at their preparedness plans.
South Korea on Thursday confirmed its third case of swine flu while China started lifting a seven-day quarantine on passengers who had shared a flight from Mexico with a man who later tested positive for swine flu.
Fukuda said, however, that vigilance was necessary.
Complacency is the greatest danger, he said. It does appear to be a period where the virus may be seeding itself in various parts of the world.
He added: What we are seeing now is milder than in 1918 (when up to 50 million people died). But the 1918 started mild in springtime and became more severe in winter.
Developing nations in the southern hemisphere, where it is currently the flu season, could be particularly at risk if the virus spreads there, he said, especially in Africa.
Meanwhile the World Bank official warned swine flu was likely to compound global economic woes.
Toomas Palu, of the institutions human development sector, told reporters at the sidelines of the meeting the full effects of the virus were still unclear, but warned policymakers against overreacting.
We should not forget that the epidemic could have a severe economic impact, he said.
We need to be vigilant and not let our guard down. In the past 12 months globally... we had a fuel and food price crisis, then we had a financial crisis and now we have a flu crisis, he said.
Anne Schuchat, deputy director of the US Centres for Disease Control and Prevention, told the conference there was encouraging news about the severity of the A(H1N1) virus, with only two deaths in the United States so far.
But she said it was possible that many more losses will occur.