WHO raises pandemic alert level to 4

By Stephanie Nebehay

GENEVA (Reuters) - The World Health Organisation raised its pandemic alert level over the deadly swine flu virus to phase 4 Monday, indicating the infection could spread between humans to cause "community-level outbreaks."

Experts held four hours of emergency talks on whether to raise the alert level from phase 3 due to the outbreak which has killed up to 149 people in Mexico and spread to the United States, Canada and Europe.

"This can be interpreted as a significant step towards pandemic influenza, but also it is a phase which says that we are not there yet," acting WHO Assistant Director-General Keiji Fukuda told a teleconference.

"At this time, we think that we have taken a step in that direction but a pandemic is not considered inevitable at this time. The situation is fluid."

The scale of alert levels goes from 1 to 6. The system was set at phase 3 in 2005 when WHO introduced it to monitor bird flu. The pandemic alert level has never before been raised.

In a statement, the Geneva-based United Nations agency said that "containment of the outbreak is not feasible. The current focus should be on mitigation measures."

He said that of the confirmed human swine flu cases in Mexico, seven had come from patients who died and another 12 from people with severe respiratory disease.

The experts felt the overall picture "appeared consistent with sustained human-to-human transmission."