siin on siis ära toodud pandeemia faasid, kuidas WHO seda näeb. kes tahab võib siit pikemalt lugeda [PDF-fail] Journalist Handbook Dec. 2005

WHO has currently identified six specific phases that would cover the generation of a
pandemic:

Inter-pandemic period

Phase 1: No new influenza subtypes have been detected in humans. An influenza virus subtype that has caused human infection may be present in animals. The risk of human infection is considered to be low.

Phase 2: No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease.

Pandemic alert period

Phase 3: Human infection(s) with a new subtype are reported. There are no instances of human to human spread, or at most, rare instances of spread to a close contact.

Phase 4: Small cluster(s), meaning less than 25 people, lasting less than two weeks, with limited human to human transmission occur, but spread is still highly localized, suggesting that the virus is not well adapted to humans.

Phase 5: Larger cluster(s), meaning between 25-50 people, lasting from two to four weeks, appear. While human to human transmission is still localized, the virus appears to be increasingly better adapted to humans. Though it is not yet fully transmissible, there is a substantial pandemic risk.

Pandemic period

Phase 6: Virus transmission increases significantly, and there is sustained transmissibility in the general population.