, GENEVA, June 11 – The swine flu crisis has escalated into the world’s first influenza pandemic in 40 years, the World Health Organization declared on Thursday, after infecting tens of thousands of people in 74 countries.
WHO director general Margaret Chan said the declaration of a "moderate" pandemic should not be a cause for panic and did not mean that the death toll from A(H1N1), which currently stands at less than 150, would sharply increase.
The UN body said it was neither recommending the closure of borders nor restrictions in movement of people, goods and services in the wake of its declaration.
However it was now clear that the virus was spreading among communities beyond outside the Americas where it was first detected in April and the world must guard against complacency.
"We will be raising our pandemic alert level to level six; and this means that the world is moving into the early days of its first influenza pandemic in the 21st century," Chan told reporters after a meeting of scientific experts to discuss the virus and its spread.
"At this time, the global assessment is that we are seeing a moderate pandemic," she added.
The UN body raised its six-phase alert level to five at the end of April, indicating that a pandemic is imminent, and officials said earlier this week that a decision to move up to the maximum level was "very, very close".
The latest figures from the organisation show that the number of reported A(H1N1) infections has reached 27,737 in 74 countries, including 141 deaths.
The vast majority of the deaths have been in Mexico, the original epicentre of the outbreak, and no deaths have been announced outside the Americas.
"Moving to pandemic phase six level does not imply we will see increase in number of deaths or very severe cases," said Chan.
"Quite on the contrary, many people having mild disease will recover without medicine in some cases, and it is good news, but the tendency to move into complacency is our biggest concern because we need to continue to monitor this virus, follow its track and do not allow it to come back in the second wave to give us more trouble."
The declaration comes amid growing evidence that the virus, which originated in Mexico two months ago, is now being widely transmitted between humans in Asia and Europe as well as the Americas.
Hong Kong authorities Thursday ordered all primary schools in the city to be closed for two weeks after the first cluster of local swine flu cases was found in the Chinese territory.
Meanwhile in Germany, a school for Japanese youngsters in the western city of Duesseldorf was closed after 27 children tested positive for the virus.
And in Australia, four swine flu victims were admitted to intensive care wards Thursday.
Chan said that it was up to individual countries to decide how to proceed given the outbreak was now classified as a pandemic.
"The global level assessment is very different from national level assessment because it has to take into account the vulnerability of the population in a specific country and also the health system resilience," she said.
The last flu pandemic came after an outbreak of the H3N2 viral strain from 1968-69, which originated in Hong Kong, and went on to kill up to two million people.