Pandemic Phase

Definition

Novel Virus Alert

1.

•novel virus detected in one or more humans

•little or no immunity in the general population

•potential, but not inevitable precursor to a pandemic

Pandemic Alert

1.

•Novel virus demonstrates sustained person-to-person transmission and causes multiple cases in the same geographic area

Pandemic Imminent

1.

•Novel virus causing unusually high rates of morbidity and/or mortality in multiple, widespread geographic areas

Pandemic

1.

•Further spread with involvement of multiple continents; formal declaration made

"Second Wave"

1.

•Recrudescence of epidemic activity within several months following the initial wave of infection

Pandemic over

1.

•Cessation of successive pandemic "waves", accompanied by the return (in the U.S.) of the more typical wintertime "epidemic" cycle

1.