I want to start with a graph, or rather a pair of graphs, taken from Google Trends. These aren't particularly accurate and should be taken with a pinch of salt, and the same pattern is not reflected in the United States, but they illustrate a worrying point. The graph at the bottom shows media mentions of swine flu parties in the United Kingdom over time, while the top graph shows search volume from British users.

Broadly speaking then, it appears that much of the public's interest in swine flu parties, as crudely measured by Google search results, was prompted by coverage of the phenomenon in the media. This begs the question, to what extent did these parties exist prior to the media coverage of them? Did newspapers report the story, or create it?

The reason why these parties are such a bad idea should be pretty obvious - they involve deliberately making children ill, the majority of whom would never have been ill in the first place; and if enough people take part they cause the illness to spread much more rapidly through the population than it would otherwise. With vaccines not yet widely available and health workers racing to prepare ahead of the expected winter outbreak it's a particularly short-sighted approach to take, and of course there's no guarantee that little Tarquin will be immune anyway.

The response of the British government and media to swine flu has been generally poor and dithering. Swine flu is a very genuine threat, but it's the sort of threat that's hard to convey to the public - possibly very dangerous but unpredictable, and likely to be slow moving for many months. Media coverage inevitably veered wildly between predicting "Parmageddon" and mocking the "scare-mongering". In the meantime, swine flu has spread, affecting several thousand people and killing a handful so far - children have been particularly vulnerable. The failure to contain the pandemic in the UK led to the government abandoning their containment strategy last week and adopting an aggressive treatment policy.

Against this background, the first mentions of swine flu parties appeared on Mumsnet.com, an internet forum frequented by middle class mothers. As the website's founder, Justine Roberts, explained to The Independent, there was no evidence that any parties had been arranged, merely a discussion of "the principle of whether it might be a good idea." Roberts gave an odd defense of this thinking in The Independent:

"Ms Roberts said she believed parents had become confused by the Government's policy of keeping schools open while at the same time telling them to take all precautions against their children contracting the virus.

'No one wants to cause hysteria, she said. 'The Government has an agenda, I assume, about having to control the infection, but the truth of the matter is either you should get it now or try to avoid getting it – you can't have it both ways. It's so easy to give a glib representation of ignorant parents who are acting hysterically.'"

The government, I imagine, took the view that mass closures of schools that would be breaking up for the summer soon anyway, during exam periods, would be going to far, but what I don't understand is how the suggestion that people should continue to go about their ordinary lives, while remaining vigilant, is somehow morphed into "you should get it now."

At any rate, at the time of writing I've seen no evidence whatsoever that any such parties have actually taken place. The entire story seems to be based on claims from a person promoting a parenting website that the idea has been discussed on an internet forum. In short, it was a non-story.

And yet on the basis of this non-story, Roberts was interviewed by national newspapers, mentioned in Time and appeared on radio shows to 'debate' public health policy with health professionals. In the Independent article I cited earlier, a website owner is given 4 paragraphs in which to state their views, while the Government's chief medical officer Sir Liam Donaldson, representing the views of basically the entire British medical profession, gets just two and a bit!

Of course there is a case for reporting and addressing the concerns of parents. Doubtless government advice can be confusing (and at times confused), and so responsible coverage of the issues involved is a Good Thing. The problem is that, as far as I and others who have researched this can make out, swine flu parties don't exist. Far from addressing the issue, Roberts is being given a vast platform on which to promote it (and of course her website). In all probability the vast majority of parents had never even heard of or considered the idea before it burst into the newspapers.

So the story of the swine flu parties was never real, but there's a certain relentlessness about the largely unconscious creation of the media myth. There's no reason to believe that at any stage people made things up - rather a grain of truth was shaped and polished and embellished in a machine that seems to run on autopilot. The result is a fusion of fact and myth that exists in its own reality, and yet - if the rough results from Google Trends are anything to go by - is beginning to distort our own. By the end of the summer, the story could well be real, and if it is then it will have been created by the media.