The World Health Organisation said today the evolution of the swine flu outbreak into a pandemic was not inevitable but countries should prepare for the worst.
"Countries should take the opportunity to prepare for a pandemic," WHO acting assistant director-general Keiji Fukuda told reporters in Geneva.
Mr Fukuda said the organisation was turning its focus more towards the needs of developing countries in fighting the outbreak, which history shows usually get hit the hardest. "They really get hit disproportionately hard," he said.
The new strain of swine flu virus that has killed up to 149 people in Mexico spread to more countries today, raising the spectre of a pandemic and hurting financial markets.
The WHO is awaiting formal confirmation from US authorities the new swine flu virus has spread significantly between people, a sign that could indicate an "imminent" influenza pandemic.
Confirmation infected people in two countries are spreading the new disease to their families or contacts in a sustained way would meet the World Health Organisation's criteria for declaring a phase 5 alert on its scale of 1 to 6. The United Nations agency raised its pandemic alert level to phase 4 from phase 3 yesterday as the virus spread to Europe.
The US Centres for Disease Control and Prevention (CDC) said today some people who have had contact with confirmed cases were also developing flu-like symptoms.
"It appears, and I think we're still awaiting for a final confirmation from the US authorities, but it appears that there's a number of cases in New York which appear to be human-to-human transmission," WHO spokesman Gregory Hartl told a news briefing.
Such secondary transmission of the virus was "probable", he later told reporters, adding: "If we have a confirmation from the United States or Canada, we could move to phase 5."
The emergency committee which recommended moving to phase 4 late yesterday - a "turning point", according to Mr Hartl - was not scheduled to meet today. But its experts could be convened at any time to make such decisions.
People have occasionally caught swine flu from a pig but it has stopped there. Avian influenza has occasionally spread from one person to just one other person and stopped there. But the new H1N1 flu appears to be spreading beyond that limited chain, which is what worries the WHO.
More than 15 WHO epidemiological experts have been deployed in Mexico to help authorities combat the outbreaks in the capital Mexico City and two other areas.
In all, the WHO has official laboratory confirmation of a total of 79 cases of the new swine flu virus worldwide. They include confirmed cases in the United States, Mexico, Canada, Spain, New Zealand, Israel and Scotland.
So far, all suspected and confirmed cases of swine flu in the current outbreak have involved infection from another person, unlike human cases of bird flu that mostly involve contact with infected poultry.
Reuters