WHO revises scale for pandemic alerts

GENEVA (Reuters) - The World Health Organization (WHO) revised on Monday its 6-point scale for pandemic alerts, saying that phase 5 would correspond to a strong signal that a pandemic is "imminent."

The revised scale was published ahead of a decision by an advisory body of experts on whether to raise the alert level from the current level of 3.

In a report posted on its website, the WHO said that under the new criteria:

* Phase 4 is characterized by human-to-human spread of a new virus able to cause community-level outbreaks

* Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one region

* Phase 6 is a global pandemic characterized by widespread outbreaks in more than one region.

"While most countries will not be affected at this stage, the declaration of phase 5 is a strong signal that a pandemic is imminent and that the time to finalize the organization, communication and implementation of the planned mitigation measures is short," it said.

(Reporting by Stephanie Nebehay and Jonathan Lynn)