The Continuum of Pandemic Phases

00:01 So, the WHO does a lot of thinking about pandemics and how to plan for them and how to control them and think about them.

00:09 So when they think about pandemic diseases, they're very often thinking about influenza because we deal with a pandemic influenza often, and there's always another one around the corner.

00:21 The yearly flu epidemic can be considered a pandemic.

00:26 It's not declared as such because that tends to be an administrative thing.

00:31 But by the soft definitions I've given you so far, the flu every year is a pandemic.

00:37 So it begins with an inter-pandemic phase.

00:41 That's the period before we have the pandemic every year.

00:46 Then of course the Alert Phase where we start noticing cases popping up in key parts around the world.

00:53 Then the pandemic itself begins.

00:56 That should be PANdemic, not pandemic.

00:59 So that's when cases are prevalent, incidence rates are high.

01:04 The pandemic is raging.

01:06 The pandemic starts to wane and we start transitioning out of the pandemic phase.

01:12 But there might be a small second wave before this is done.

01:15 Then we re-enter the interpandemic phase and wait out the start of the next pandemic.

01:23 Note that important administrative tasks must be done in these various phases.

01:28 During the alert phase and the end of the interpandemic phase, we start to ramp up our detection capacity using our surveillance tools and verifying that these cases genuinely are the disease we think it is, in this case the "flu".

01:42 And we monitor the pandemic while it's raging around the world to determine where it is, whether it's spreading out of control and which regions need more resources.

01:54 Keep in mind though that even though during the interpandemic phase, the cases are low or nonexistent, we are always looking.

02:02 Right, we just shift from preparedness to recovery and back to preparedness.

02:08 We must always be in a state of readiness to deal with these pandemics.