No more magic bullets

A DRUG for every bug? Not any more

A DRUG for every bug? Not any more. This week, the World Health Organisation issued a report that reads like an episode from The X Files, but is in fact a wake up call of deadly seriousness. No one knows what is out there any longer. "Without doubt, diseases as yet unknown, but with the potential to be the AIDS of tomorrow, lurk in the shadows", said she report from an agency not known for an alarmist tendency. The problem? Antibiotic resistant organisms. The cause? It's complacency, stupid.

Fifty years ago, antibiotics were bailed as miracle drugs, "magic bullets" in the war against once deadly bacterial infections such as pneumonia, tuberculosis and meningitis. For a few decades, it seemed no one would ever have to die of pneumonia or tuberculosis again. But then the bugs began to bite back. Using barely believable powers of mutation, they began transforming themselves into doomsday superbugs resistant, to some, or even all, types of antibiotics.

Antibiotic resistant forms of tuberculosis are already causing problems in New York city. In the Third World, antibiotic resistant malaria, gonorrhoea, cholera and typhoid are becoming major killers. Traveller's diarrhoea has become so resistant to treatment that during the Gulf War, one in five US soldiers was out of action as a result. Strains of pneumococci - the most common bacteria causing acute respiratory infections in children - once uniformly susceptible to penicillin, are now resistant in up to 18 per cent of cases in the US and 40 per cent in South Africa. "The resistant organisms that are being produced are a whole new generation of organisms," Ralph Henderson, WHO's assistant director general warned. "This resistance problem is one that I think is going, to be a major plague for the coming century."

In the West, hospitals are engaged in a fierce and increasingly unequal struggle to fight off MRSA - methicillin resistant staphylococcus aureus - an acronym for a whole range of stubborn and potentially deadly forms of infection which thrive in the hospital environment, infect the most vulnerable patients and resist all or almost all antibiotics.

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MRSA has come to dominate medical conferences and poses huge problems for hospitals on a daily basis. It is well known in Irish medical circles that the transfer of patients from one hospital to another is one of the major sources of MRSA infection, Yet, transferring hospitals sometimes "forget" to mention that a patient has MRSA because the admitting hospital may refuse to accept him. Professor Conor Keane from the microbiology department at St James's Hospital, agrees that MRSA has caused deaths in Irish hospitals: "But more commonly," he says, "it causes severe morbidity, which means prolonged hospital stays, isolating the patient and leading to increased costs, because by definition the drugs being used will be more expensive.

In the US it is estimated that antibiotic resistant bacteria are responsible for up to 60 per cent of hospital acquired infections. In some areas, staphylococci, which can contribute to skin infections, food poisoning and other serious disorders, have developed resistance to all antibiotics except vancomycin. But the WHO report warns that if vancomycin resistant strains were to emerge, some of the most prevalent hospital acquired infections could not be treated. This is the doomsday scenario.

"Disastrously, this is happening at a time when too few new drugs are being developed to replace those that have lost their effectiveness," the report says. "In the contest for supremacy, the microbes are sprinting ahead. The gap between their ability to mutate into drug resistant strains and man's ability to counter them is widening fast."

In 1993, Professor Michael Levin, head of the department of infectious diseases in children at St. Mary's Hospital, London, issued a dire warning in his Darwin Lecture. With special reference to children, he stated that "so great is the number of new or re emerging infectious diseases that it would be impossible even to mention a small proportion of them". Among those he listed were septicaemia, meningitis, pneumonia, nephritis, bacterial infections of the bones and joints, gonorrhoea, tuberculosis, cholera and typhoid fever, all increasing and often in new or drug resistant forms.

So what went wrong? Where did the fairytale scenario of the "magic bullet" go so horribly awry? Overuse and abuse of antibiotics is largely to blame, it appears, and we therefore have no one to blame but ourselves.

This is no unavoidable, natural disaster. We are now paying the price for our decades of awe of the medical profession, for our reluctance to leave a GP's surgery without a prescription and conversely for our dumb acceptance of whatever the mighty doctor orders, for our impatience with the natural course of infection, for our senseless squandering of antibiotics, one of man's most precious resources.

Overuse is indisputable. "There's an overload of people just using them like aspirin," says Dr Martin Wood, editor in chief of the Journal of Antimicrobial Chemotherapy. In Geoffrey Cannon's book, Superbug: Nature's Revenge, Professor Richard Lacey of Leeds University states that of all the people who have had their infections identified in this laboratory, less than one in 100 had been treated with appropriate antibiotics. And most of these diseases are self limiting anyway - that is, they will eventually clear up by themselves without any use of drugs.

The problem with overuse is obvious. In a population of many millions of bacteria, there will be some chance - mutants, maybe just one in a million, that happen to be invulnerable to the drug that kills the others. These previously insignificant mutants survive, multiply and colonise the space left by the destruction of all the other bacteria. In this way, the intestines become factories producing dangerous bacteria which can outsmart the drugs.

Cannon compares antibiotics to clumsily targeted Scud missiles. For 50 years, doctors have hurled millions of Scuds in the form of broad spectrum antibiotics into the body to kill a few dangerous bacteria, but too often the Scuds have missed their intended target, while killing masses of beneficial bacteria.

Meanwhile, the harmful bacteria which have survived have learned not only to avoid the Scuds, but have also developed their own precise "Patriots" to intercept the Scuds. To compound the problem, when one type of bacteria learns to evade antibiotics it can confer that ability on others, turning previously harmless bacteria into killers.

THE issue is both personal and global. At a personal level, Cannon claims that taking unnecessary antibiotics can set a vicious cycle in motion by which the next antibiotic you take may be for an infection caused by the last antibiotic you took, which has made you vulnerable to superinfection, so that you get more infections that make you more ill, so that you take more antibiotics, and so on . . .

In fact, Cannon suggests that repeated use of antibiotics is liable to damage the mucosal lining of the gut wall and thus our immune defences, and for this and other reasons, argues that they may well be a cause of a number of mysterious modern diseases such as irritable bowel syndrome, some forms of arthritis and ME.

You could of course be highly socially responsible and/or lucky and manage to avoid antibiotics all your life. But you could still become ill with disease caused by a superbug merely through breathing the same air in cinemas and shopping centres as people who have developed drug resistant bacteria. No one is safe any more, says WHO.

"We are standing on the brink of a global crisis in infectious diseases. No country is safe from them. No country can any longer afford to ignore their threat."

Scientists have been aware for 20 years that bacteria have been breaching the bulwarks. Long before the WHO report, individuals and interested bodies were calling for tighter controls on the way antibiotics were dispensed. But anyone seeking change in this area is also tangling with the marketing might, money and global power of the pharmaceutical companies for whom antibiotics have long been a licence to print money.

"For industry," writes Geoffrey Cannon, "antibiotics are dream drugs; the more they are used, the more bacteria develop resistance. So industry patents and markets ever more expensive products, which in turn become obsolescent ... and the drug treadmill turns ever faster." According to Cannon, when the US National Institute of Health attempted a global initiative in the mid 1980s designed to stop antibiotic misuse, their work was thwarted by a number of major pharmaceutical companies able to put pressure on the White House.

Meanwhile, in the Third World, antibiotics are chaotically, widely available, often over the counter, in vast quantities and used unnecessarily for complaints like headaches and tooth cavities. One theory described by Cannon is that this ignorant misuse could foster a plague which jumps continents by jumbo jet until the entire planet is affected.

Back in the Republic of Ireland, we still have no public health laboratory, no proper surveillance system for infectious diseases as required by the Maastricht Treaty. Moves are afoot by the Department of Health, but in the interim we have only patchy, inaccurate figures to rely on. The truth is out there to be sure, but are we too late with the remedy?

Kathy Sheridan

Kathy Sheridan

Kathy Sheridan, a contributor to The Irish Times, writes a weekly opinion column