WHO PANDEMIC ALERT PHASES

Phase 1: No infections in humans are being caused by viruses circulating in animals.












Phase 2: Animal flu virus causes infection in humans, and is a potential pandemic threat.












Phase 3: Flu causes sporadic cases in people, but no significant human-to-human transmission.












Phase 4: Human-to-human transmission and community-level outbreaks.












Phase 5: Human-to-human transmission in at least two countries. Strong signal pandemic
imminent.











Phase 6: Virus spreads to another country in a different region. Global pandemic under way.












Post-peak: Pandemic activity appears to be decreasing though second wave possible.
Post-pandemic: activity returns to normal, seasonal flu levels.

Source: Swine Influenza Top News