Paranoia was at its height - had I been near any strange ducks recently?

Thomas Sutcliffe an education in influenza

There was a time when I didn't believe in flu. Tone of voice is always difficult in print, so perhaps I should attach a small sketch to allow you to reconstitute this phrase exactly as it leaves me. Imagine a voice saying: "There was a time when I didn't believe in tigers." Then, limping badly, the speaker comes into view. His face is pallid with shock, there is a large, bleeding bitemark on his thigh and his clothes hang from him in ribbons. (For real verisimilitude you should add an ominous offstage growl; what follows is written largely in the supplicatory past tense but I'm not convinced the beast has finished toying with me yet).

Of course I knew that something called "flu" existed in the collective conscious, that it was invoked with great frequency at certain times of the year to account for absences or below par performance but I took this not as a serious medical diagnosis but as a kind of informal social understanding. In the pre-Birt days the BBC used to give its employees two bisques a year - a term borrowed from the Civil Service (which had in turn borrowed it from croquet). A bisque was a day off that could be taken without warning and without explanation - however disruptive it might be. And I thought that "the flu" was something like an informal substitute for this humane device. People took their "flu" days in twos, or occasionally threes, and you weren't expected to ask questions when they reappeared looking perfectly hale on the fourth. And flu's distinction from proper diseases was emphasised by two further facts - nobody was ever expected to die from it (except for those so fragile they might have been carried off by the sound of a balloon bursting) and there was nothing much doctors could do. Indeed I thought "flu" suited them too because it was so much less embarrassing than saying, "Well, Mrs Simmons, you appear to be what we doctors call `under the weather'."

This delusion was fostered by the fact that I didn't get flu for years and years - so I had absolutely no personal experience to which I could attach the word. My re-education came in two parts. First I did the theory: I read a fascinating article in September's New Yorker about the hunt to discover the exact nature of the deadly Spanish Influenza 1918, a pandemic which killed over 20 million people. As well as detailing the attempt to exhume what may be the last well-preserved specimen of the virus - from seven Norwegian miners buried in permafrost in the Arctic town of Longyearben - Malcolm Gladwell's piece also described the worldwide viral meteorology by which new strains of this mercurial disease are identified and tracked. More frighteningly it described how waterfowl act as the "reservoir" for influenza strains. It is through them that the disease finds its way to other animals and then to us and it is through them that any modern version of the 1918 horror would both emerge and spread. Occasionally the alarm systems are triggered; earlier this year, for example, a three- year-old boy from Hong Kong died after contracting an entirely new strain of avian flu, a case that had virologists running up their international phone bills for weeks, until it became clear it was a highly unusual case, rather than the first of millions.

Then last week I did my practical. I got flu and discovered just what a dolorous assembly of symptoms that vague word describes. I still think that "pain" would be a little too fortissimo for any of them taken in isolation. Indeed there's a brief moment, when you first decide to surrender to the shakiness and take to your bed, when there's something almost delicious about it. "So this is what I've been missing," I thought as I lay tucked up snug well before bedtime, relishing the way shivers would scud across the body and then disappear, like a sea-breeze goose-bumping a sunbather on a hot summer day.

But then other instruments take up the burden; a whole orchestra of twinges, spasms aches and cramps which result in an atonal cacophony of discomfort. Lying in your clammy pit of tangled sheets you struggle to work out the principles of composition. What is the reason for the antiphonal line played out between your kneecap (which something is trying to prise free from the cartilage) and that piercing note from the hinge of your jaw? Is the theme carried by the bed of embers lying at the back of your chest (occasionally riddled into a livelier flame by a vein-popping cough) or by the glissando bone-ache which slithers down both femurs? Does the ostinato of nausea suggest some convulsive upheaval is in the offing? And why do the creaks and darting pains in your skull summon up the image of a very fat man skating on rotten ice?

It is all very dissonant and modern, but you have plenty of time to try and work it out - the performance will last for days and there is no interval. Because insomnia is thrown in too (nice finishing touch from the virus) the mind tends to wander down some very cranky pathways. Forty-eight hours in, my paranoia had reached its height. Had I been sitting too near any strange ducks recently? And if so, then how was I going to persuade my doctor to contact the Centers for Disease Control in Atlanta before it was too late?

I feel I have graduated in flu now. I don't want to take the course again. Indeed I would be very happy if I never coughed again (mostly because every cough is currently accompanied by the sensation of someone testing a stapler against my left temple). But at least I know for sure the word isn't just a euphemism for "couldn't be bothered to get out of bed this morning". From now on I am a devout believer.