It must be that time of the year again – the human race is about to be ended by a global pandemic. First there was SARS, then it was Avian Flu, then we were all going to be wiped out by West Nile Virus, and now it’s Swine Flu. Nothing sells papers like a good old-fashioned health scare. Clearly those previous outbreaks didn’t put a stop to humanity, so is there any reason to be afraid this time?

Well, perhaps a closer look at the numbers will inform us. Latest reports are that 100 people have died in Mexico. Clearly this is a tragedy for those involved, but 100 people in a country with a population of 110 million is hardly an epidemic. It’s less than a one in a million chance - if you happen to be in Mexico where the disease is apparently widespread. And what that figure conceals is that only 20 deaths have actually been confirmed as Swine Flu cases. And there are currently 1,614 cases of the disease in Mexico. So that’s 20 deaths out of 1,614. That’s a 1.2% chance of dying even if you actually catch the disease.

But let’s be honest – “You’re very unlikely to catch Swine Flu, and even if you do, you’ll probably be fine” doesn’t make for quite as catchy a headline, does it? So instead we get meaningless speculation in The Daily Express that the disease “could” kill 120 million people. Sure, it could kill that many people, but equally the earth could be struck by an asteroid, killing everyone on the planet. The question is, how likely are either occurrence? Probably not very likely. But we can’t let a little thing like statistical accuracy get in the way of a good story. Or the sale of face masks and Tamiflu.

Roche shares are up today if you’ve got any money to invest.