H1N1

What does the WHO's pandemic scale mean? And why is anyone worried about this?

http://scienceblogs.com/aetiology/2009/04/what_does_the_whos_pandemic_sc.php

This is all just media hype! Lies about the Mexican cases! The WHO just revised their numbers down to 26 cases and 7 deaths! Why should I believe the crap about this aporkalypse?

First, indeed, the Mexican cases stand at 26 cases and 7 deaths--*laboratory confirmed* cases. Even for regular influenza, the number of cases that are confirmed--much less to the level that these are, by the CDC or other high-level labs--is extremely small. We always expect many fewer confirmed cases than reported cases, because for a number of reasons, some people who display all the symptoms of a disease will be difficult to confirm. Maybe they were unable to get to a hospital in time for a sample to be taken; maybe they live in a remote area where it's difficult to ship samples from; maybe they came in too late after their disease had already cleared, and no live virus was present in their system anymore; and on and on. Most of the Mexican cases (the thousands reported) have been suggested to be H1N1 based on symptoms and timing. The current WHO report isn't saying that these 26 cases are the ONLY H1N1 cases in Mexico--these are just the ones they're absolutely, positively, 100% sure are swine flu.

Ordinary flu kills 36,000 Americans a year. Why should I care about this "swine flu," when only a hundred or so cases have been reported in the US?

Yes, ordinary flu is a *****, and most people don't worry about it one iota. (Mike laments this situation). However, ordinary flu kills these 36,000 people *despite* many of us having some pre-existing immunity to the circulating strains, and a percentage of the high-risk groups receiving vaccination. With these new strains, it's unlikely that the population as a whole will have much cross-protective immunity, meaning higher numbers of people will get sick and die than a "regular" flu year, and all the impact to society and the economy that goes along with an ill population.