GENEVA The World Health Organization is keeping a close eye on the spread of the H1N1 virus outside North America as it tries to decide whether to declare a pandemic, a top official said on Monday.
Keiji Fukuda, WHO acting assistant director-general, said most of the people infected in Europe and Asia to date had been to Mexico, the outbreak epicenter, and had not caught the virus from the community-at-large.
It remains unclear when, or whether, the United Nations agency will raise its pandemic alert to the top of its 6-point scale and activate emergency response plans to fight the virus known popularly as "swine flu."
"We continue to see a number of infections related to travel in a number of different countries," Fukuda told journalists in Geneva, where the WHO is headquartered.
"We are not certain when we will go to Phase 6." He stressed a designation of a full pandemic would not mean the WHO expected widespread death or severe illness from the strain.
The main concern, he said, is whether the disease takes hold in countries around the world and could emerge in a mutated or more dangerous form with time.
Its spread to countries in the southern hemisphere, like New Zealand, that are entering the winter season when flu tends to be most acute is a particular worry, according to Fukuda.
He emphasized that although Mexican authorities have said the flu outbreak there has passed its peak, the world should not drop its guard and stop monitoring the new disease.
"It is not that surveillance has to be strong just in the southern hemisphere. It has to be strong everywhere. Right now we really just don't know how this will go," Fukuda said.
The WHO has confirmed 1,025 infections, including 26 deaths, in 20 countries around the world. Many people have experienced only mild symptoms from the flu and recovered fully without medicines.
Earlier on Monday, U.N. Secretary-General Ban Ki-moon said that WHO chief Margaret Chan had told him "that if the situation remains as it is, WHO has no plan to raise the alert level to 6 at this moment."
Last week the WHO raised its pandemic alert level from 3 to 4 to 5 in recognition of the transmission of the virus in Mexico and among communities in the United States and Canada. Phase 5 signals that a pandemic is "imminent."
Asked about the reported spread of H1N1 from a farm worker to a herd of swine in western Canada, Fukuda warned against putting too much emphasis on the animal outbreak. He said human-to-human spread of the virus remained the bigger concern.
"Influenza is a virus that commonly infects pigs," he said. "I don't know of any further outbreaks occurring in pigs at this time."
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