World Health State/Local Organization Federal indicators indicators for CDC phases CDC intervals for CDC intervals intervals Pandemic phase: Initiation: Confirmation of Confirmation of Global spread of Initiation of a human cases of a human cases of a human influenza pandemic wave pandemic influenza pandemic influenza caused by a new virus anywhere in virus in the United subtype the world with States with demonstrated demonstrated efficient and efficient and sustained human- sustained human- to-human -- to-human transmission transmission Acceleration: Consistently Consistently Acceleration of a increasing rate of increasing rate of pandemic wave pandemic influenza pandemic influenza cases identified in cases identified in the United States, the state, indicating indicating established established transmission transmission Deceleration: Consistently Consistently Deceleration of a decreasing rate of decreasing rate of pandemic wave pandemic influenza pandemic influenza cases in the United cases in the state States Transition phase: Preparation: Low pandemic Low pandemic Reduction in Preparation for influenza activity but influenza activity but global risk, future pandemic continued outbreaks continued outbreaks reduction in waves possible in some possible in the state response jurisdictions activities, or progression toward recovery actions 49