Thursday, May 7, 2009

Why are we still in Phase 5? Why so much attention?

Here's some notes that we gleaned from the latest WHO conference call that can help answer some common questions people have at this stage

Why are we still in Phase 5?

We are still seeing human-to-human, community-level transmission in North America only, not anywhere else. We would need to see community-level transmission (which means it's spreading easily within the community) rather than sporadic cases from people returning from travel. Since we haven't seen that, we are still in phase 5.

Why are we paying so much attention to this virus, especially when so many cases are mild?

From the beginning of this situation a few weeks ago, WHO has said the situation was evolving and didn’t know where it was going to go. Virus has gone to a number of countries, and is established in just 2. We still don’t know why or have a full picture of the situation. Two critical questions remaining are:

  • Most of the activity is in the northern hemisphere. Will it spread in the Southern hemispehere? What will happen when it does?
  • Will the virus change, and become more dangerous later this year or in the next few years?

If we move into a pandemic, we will see a large number of people to be infected worldwide, maybe up to 1/3 of the world’s population. When you look at a world of 6 billion people, that’s a lot of people to be infected. Even if not a big deal on the individual level, we’re talking about big numbers, so there could be a lot of people with pneumonia and complications.

When the southern hemisphere goes to winter, that’s when we see more influenza virus. The population in the southern hemisphere is different – younger populations in developing countries, often more vulnerable (because malnourished, war, HIV…). Have seen that when seasonal influenza hits, what is mild in the developed could be quite severe in developing world.

Pandemics don’t occur in a couple of days – this could happen over a 2-year period. WHO sees that this is the time to work with countries so that there are more prepared for the increase in people getting sick.

Thanks to colleagues from American Red Cross for notes on WHO briefings!

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