April 27 (Reuters) - The World Health Organisation (WHO) revised on Monday its 6-point scale for pandemic alerts, saying that phase 5 would correspond to a strong signal that a pandemic was "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. WHO uses a series of six phases of pandemic alert as a system for informing the world of the seriousness of the threat and the need to launch progressively more intense preparations and measures. Margaret Chan, director-general of the United Nations agency in Geneva, is charged with deciding on when to move from one phase to another. Her decision is based on advice from international public health experts who held an emergency meeting on Monday. The WHO emergency committee is assessing the risk from a swine flu outbreak that has killed up to 149 people in Mexico and spread across the world. The current phase of alert is 3, on a scale of 1 to 6. A full-blown pandemic, level 6, denotes sustained, human-to-human spread over many countries of a new and serious virus. Here are details of the six phases: -- PHASES 1-3: Predominantly animal infections: few human infections * PHASE 1: No animal influenza virus circulating among animals is reported to cause infection in animals. * PHASE 2: Animal influenza virus is known to have caused infection in humans and is therefore a potential pandemic threat * PHASE 3: Animal or human-animal influenza virus causes sporadic cases or clusters of cases in people, but no human-to-human transmission, except in specific circumstances -- PHASE 4 Sustained human-to-human transmissions * PHASE 4: Human to human transmission of an animal or human-animal influenza virus able to sustain community-level outbreaks "The ability to cause sustained disease outbreaks in a community marks a significant upwards shift in the risk for a pandemic." -- PHASES 5-6/PANDEMIC Widespread human infection * PHASE 5: The same virus causes sustained community-level outbreaks in two or more countries in 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 finalise the organisation, communication, and implementation of the planned mitigation measures is short." * PHASE 6: The virus causes sustained community-level outbreaks in more than one region "Designation of this phase will indicate that a global pandemic is under way." -- POST PEAK Possibility of recurrent events Pandemic levels dropping below peak levels, but countries need to be prepared for a second wave. -- POST PANDEMIC Disease activity at seasonal levels Sources: World Health Organisation (For a summary of the new WHO scale, go to: http://www.who.int/csr/disease/influenza/GIPA3AideMemoire.pdf ) (For the WHO guidance document on pandemic preparedness go to: http://www.who.int/csr/disease/influenza/PIPGuidance09.pdf )
(For more Reuters stories on swine flu, click on [nFLU]) (For more Reuters swine flu coverage, please click here: http://www.reuters.com/news/globalcoverage/swineflu ) (For WHO information on swine flu, go to: http://www.who.int/csr/disease/swineflu/en/index.html ) (Compiled by Stephanie Nebehay and Jonathan Lynn; Editing by Robert Woodward)
Spanish Health Minister Trinidad Jimenez addresses the media in Madrid April 27, 2009. Spain became the first country in Europe to confirm a case of swine flu on Monday when a ...
