WHO (World Health Organisation) Phases for a Possible Pandemic
Inter-pandemic period
Phase 1 - No new influenza virus subtypes have been detected in humans. An influenza virus subtype that has cause human infection may be present in animals. If present in animals, the risk of human infection or disease is considered to be low.
Phase 2 - No new influenza virus subtypes have been detected in humans. However, a circulated animal influenza virus subtype poses a substantial risk of human disease.
Pandemic Alert Period
Phase 3 - Human infection(s) with a new subtype, but no new human-to-human spread, or at most rare instances of spread to a close contact.
Phase 4 - Small cluster(s) with limited human-to-human transmission but spread is highly localised, suggesting that the virus is not well adapted to humans.
Phase 5 - Large cluster(s) but human-to-human spread still localised, suggesting that the virus is becoming increasingly better adapted to humans, but may not yet be fully transmissible (substantial pandemic risk).
Pandemic Period
Phase 6 - Pandemic phase: increased and sustained transmission in the general population.
References and Useful Websites
For additional information regarding Swine Flu, please visit the following links
