No other disease has been responsible for so much social upheaval, ranging from a crusade, to the discovery that the medical profession is seldom as competent as it claims

Since this article is to be published after the dreaded date 1 January , it is just possible no one may ever read it. If the most pessimistic millennium doom-mongers are correct, by the time this issue of HSJ should have hit its eager readers desks there may be no desks on which to drop it - fleets of aeroplanes having fallen from the skies destroying much of the NHS estate.

On the other hand, things may not be quite so bad. As an optimist I'm betting on the millennium bug amounting to nothing more than the electronic equivalent of a runny nose compared to the worst-case scenario of it being the digital version of cholera.

Millennium fever has, however , produced not only its doom-laden hallucinations but a rash of millennium awards: sports personality of the millennium, songwriter of the millennium and best film of the millennium. I'm prompted to ask what sickness causing agent should win the award for bug of the millennium?

Nominations aren't difficult to find, although the popularity of most diseases has waxed and waned over the centuries. Leprosy , extremely popular until the 14th century, rarely features in todays bar-room debates. On the other hand, AIDS - despite being a Johnny-come-lately among the truly great sicknesses - must be a strong contender for the Third Horseman trophy .

Typhoids 19th century British debut included such unforgettable highlights as the death of Prince Albert and Queen Victoria's record breaking period of mourning. But typhoid, like malaria and yellow fever, is now largely confined to faraway places of which we know little and is consequently unlikely to receive many votes.

Syphilis, too, which would once have been a strong contender , has fallen far down the charts. The French disease , which made its European debut in 1492 as America s first export, did, however, cause medical mayhem for over 400 years before the discovery of Salvarsan - the original magic bullet - by Paul Ehrlich in 1909. Yet even today , who can ever forget Christopher Columbus's tragic remark in his otherwise triumphant return to Spain: T engo una erupci n horrible y dolorosa en mi pene, doctor - There's something wrong with my thingy, doctor.

There is of course more than one kind of pox. Smallpox, despite its self effacing name, enjoyed enormous success for many centuries until its virtual demise at the millenniums end; it now survives only in much reduced circumstances sealed in laboratories in the US and Russia.

Smallpox must be a front-runner for an award: if America gave Europe syphilis, Europeans repaid the debt in spades. It was not the conquistadors who conquered the Americas but their diseases: Cortez managed to inadvertently kill 3.5 million Aztecs with smallpox - within 10 years, more than 90 per cent of the population of central America had been wiped out. Smallpox really is a major league disease.

Perhaps one important test of a major disease is the degree of kudos gained by the doctor or scientist who finds the cure - or at least is first to register their claim. Maybe the status of smallpox can be gauged by the number claiming to have invented vaccination: Fewster in 1765, Bose in 1769, Jesty in 1774, Nashe in 1781, Platt and Jensen in 1791. But it was Edward Jenner who took pus from cowpox-infected milk maid Sarah Nelmes and scratched it onto the arm of eight-year old James Phipps in 1796, whose reputation survives. Perhaps someone will nominate Jenner as physician of the millennium.

Quite what criteria should be used for nominating the bug of the millennium is arguable. The familiar - such as the common cold - might rate a place simply for being ubiquitous, as might influenza, which deserves special mention for having killed off 25 million in 1918 alone - far more than did the First World War. But surely to rank as the true sovereign among diseases, more important criteria should be met: the disease should be spectacularly virulent, it should have been around for a long time, it should still be with us and it should have had a deep sociological impact.

Using these criteria, many diseases fail to make the grade: leprosy is among the most difficult diseases to catch, to all intents and purposes smallpox is extinct, AIDS has barely existed for half a century and the common cold - while sustaining the paper tissue industry - can hardly be described as earthshaking. Only one disease is truly worthy of the ultimate accolade - the plague.

The plague has certainly been wonderfully virulent: during the Black Death in the 14th century it killed 75 million people in Eurasia, a third of the population. And it has been around for a long time: the plague can even claim to have been the most devastating disease in two millennia, having wiped out perhaps 100 million people 800 years earlier in 542 AD.

Even today we cannot be complacent: the last outbreak in the UK was as recent as 1910, and according to the World Health Organisation, between 1965-70 there were 175,000 cases of plague in Vietnam, and there continue to be on average 1,000 cases each year worldwide. The US alone had at least eight minor epidemics between 1900 and 1950, and reservoirs of the disease remain in Africa, Australia, Asia and the Americas.

No other disease has been responsible for so much social upheaval, ranging from a crusade, pogroms against Jews, the redistribution of wealth, heresy and religious reform, the breakdown of the feudal system, the cessation of at least one war and the important discovery by both patients and doctors that the medical profession is seldom as competent as it claims to be.

So, unless anyone can convince me otherwise, I'm definitely giving the plague bacillus Yersinia Pestis my vote for the title Bug of the Millennium.