WHO Raises Pandemic Threat Level to Phase 5

In a statement today, Director General Chan of the WHO decided, on expert advice from a Committee convened for this purpose, to raise the current level of influenza pandemic alert from phase 4 to phase 5.

This move has been expected the past 24 hours as evidence of community-level transmission begins to surface in NYC. While the definition notes that Phase 5 is only a signal that a pandemic is imminent, Director General Chan made it clear in her statement that she expects a declaration of "pandemic" to be forthcoming as more information is gathered.

What remains to be seen however is how severe this virus, and a pandemic, may be. Investigations continue. In the meantime this declaration signals to governments, multilateral institutions, and manufacturers in the health sector to begin preparing for a pandemic now.

WHO's definition of a pandemic:
"Phase 5 is characterized by human-to-human spread of the virus into at least two countries in one WHO region (Figure 4). 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."

WHO:
http://www.who.int/en/
http://www.who.int/mediacentre/news/statements/2009/h1n1_20090429/en/index.html