Last updated:
 22 June 2010

Currently at Level 5 alert

The WHO pandemic alert levels

Phases 1-3
Predominantly animal infections: few human infections.
Phase 1
New 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 transmission.
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.
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.

(For more details on the WHO website click here)