Phase 2 No new influenza virus Minimize the risk of Minimize the risk of – subtypes detected in humans. transmission to humans; transmission to humans; However, a circulating animal influenza detect and report such ensure that staff members virus subtype poses substantial risk of transmission rapidly if it understand detection and human disease. occurs. reporting guidelines and report rapidly as required. Pandemic Alert Period Ensure rapid characterization Ensure all personnel are Phase 3 Human infection(s) are – of the new virus subtype and knowledgeable about the occurring with a new subtype, but no early detection, notification latest epidemiological human-to-human spread, or at most and response to additional information rare instances of spread to a close cases. contact. Phase 4 Small cluster(s) of human Contain the new within Ensure that best practices for – infection with limited human-to-human limited foci or delay spread to infection detection and control transmission but spread is highly gain time to implement measures are followed. localized suggesting that the virus is preparedness measures, not well adapted to humans. including vaccine development.
Phase 2 – No new influenza virus subtypes detected in humans. However, a circulating animal influenza virus subtype poses substantial risk of human disease. Minimize the risk of transmission to humans; detect and report such transmission rapidly if it occurs. Minimize the risk of transmission to humans; ensure that staff members understand detection and reporting guidelines and report rapidly as required. Pandemic Alert Period Phase 3 – Human infection(s) are occurring with a new subtype, but no human-to-human spread, or at most rare instances of spread to a close contact. Ensure rapid characterization of the new virus subtype and early detection, notification and response to additional cases. Ensure all personnel are knowledgeable about the latest epidemiological information Phase 4 – Small cluster(s) of human infection with limited human-to-human transmission but spread is highly localized suggesting that the virus is not well adapted to humans. Contain the new within limited foci or delay spread to gain time to implement preparedness measures, including vaccine development. Ensure that best practices for infection detection and control measures are followed.