First it was the emails, and the tweets. This is all nonsense about the aporkalypse, surely? Just like with Sars, and bird flu, and MMR, is this all hype? The answer is no, but more interesting is this: for so many people, their very first assumption on the story is that the media are lying. It is the story of the boy who cried wolf.

We are poorly equipped to think around issues involving risk, and infectious diseases epidemiology is a tricky business: the error margins on the models are wide, and it's extremely hard to make clear predictions.

Here's an example. In Glasgow in the 1980s, less than 5% of injecting drug users were HIV positive. In Edinburgh at the same time, it was almost 50%, even though these two places are only an hour apart by train. Lots of people have got theories about why there should have been such a huge difference in the numbers of people infected, and there's no doubt that it's fun to try and come up with a plausible post hoc rationale. But you certainly wouldn't have predicted it.

Maybe some bloke with HIV got off the train at Edinburgh station instead of Glasgow on a whim, some fateful day in the early 1980s.

Maybe there was a different culture among heroin users, or services.

Nobody really knows.

We face the same problem with swine flu. All people have done is raise the possibility of things really kicking off, and they are right to do so, but we don't have brilliantly accurate information. Someone has said that up to 40% of the world could be infected. Is that scaremongering? Well it's high, and I'm sure it's a bit of a guess, but maybe up to 40% could be. Annoying, isn't it, not to know.

Someone has said 120 million could die. Well I suppose they could: I'm sure it was done on the back of an envelope, by guessing how many would be infected, and what proportion would die, but I don't think anyone's pretending otherwise.

You could no more predict what will happen here than you could have predicted the enormous disparity in HIV prevalence between Glasgow and Edinburgh. Everyone is just saying: we don't know, it could be bad, and the newspapers are reporting that. Sure there's a bit of vaudeville in the headlines, but they're not saying things that are wrong, and do you really know actual, real people, normally pretty solid, who are suddenly now panicking?

By Tuesday, pundit-seekers from the media were suddenly contacting me, a massive nobody, to say that swine flu is all nonsense and hype, like some kind of blind, automated naysaying device. "Will you come and talk about the media overhyping swine flu?" asked Case Notes on Radio 4. No. "We need someone to say it's all been overhyped," said BBC Wales.

I assumed they were adhering, robotically, to the "balance" template, but no: he kept at it, even when I protested and explained. "Yeah, but you know, it could be like Sars and bird flu, they didn't materialise, they were hype." Simon Jenkins suggested the same thing. It's not true, I said. They were risks, risks that didn't materialise, but they were still risks. That's what a risk is. I've never been hit by a car, but it's not idiotic to think about it. Simon Jenkins won't be right if nobody dies, he'll be lucky, like the rest of us. Do people think this flappily in casinos? The terrible truth is yes.

In the time that I have been writing this piece – no embellishment – I've had similar calls off This Week at the BBC ("Is the coverage misleading?"), Al-Jazeera English ("We wanted to talk to someone on the other side, you know, challenging the fear factor"), the Richard Bacon Show on Five Live ("Is it another media scare like Sars and bird flu?") and many more.

I'm not showing off. I know I'm a D-list public intellectual, but I just think it's interesting: because not only have the public lost all faith in the media; not only do so many people assume, now, that they are being misled; but more than that, the media themselves have lost all confidence in their own ability to give us the facts.