Drug resistantant 'superbugs'
WE have been hearing a lot about "superbugs" in recent years, both for the right and the wrong reasons. Right, because these bugs are difficult to treat with antibiotics, the "wonder drugs" of modern medicine, and therefore such superbugs could potentially cause illness and death on a large scale.
The emergence of drug-resistant strains of such deadly diseases as tuberculosis and HIV are worrying signs of this. But it is wrong to focus solely on the superbugs because they are only the most visible manifestation of the prolonged abuse of antibiotics all over the world. They are the tip of the iceberg called antimicrobial resistance.
Before the fortuitous discovery in 1928 of penicillin, our very first antibiotic, the major cause of death in mankind was infection due to microorganisms such as bacteria, fungi, parasites and viruses. Since then antimicrobial agents -- antibiotics and related medicinal drugs -- have led to a dramatic drop in deaths from diseases that were previously widespread, untreatable, and frequently fatal. Now this is under threat as disease causing microbes become more and more resistant to our wonder drugs. The iceberg will only get larger if we do nothing about it, and sooner rather than later our ship will run into it.
As part of the effort to prevent this, the World Health Organization is focusing on antimicrobial resistance on World Health Day, celebrated globally every April 7th. We are urging all to use antibiotics rationally as resistance to antibiotics is a global problem that cannot be contained in one country or one region of the world.
Developed countries have long been overusing antibiotics (and more broadly, antimicrobials), including in instances where they were not medically indicated. At the same time, in the developing world inadequate quality, underuse and poor access to drugs continue to be major components of the widespread inappropriate use of antibiotics. Through this misuse, people have given an undue advantage to harmful microorganisms and squandered one of the greatest weapons in the modern medical arsenal for combating disease.
Development of resistance in microbes is a continuous phenomenon. Their genetic system randomly and frequently undergoes changes, a few of which confer protection against antibiotics. This is called antimicrobial resistance. It is a natural survival mechanism perfected by these "bugs" over millions of years.
But inappropriate use of antibiotics selects out resistant populations of bugs, which is to say that a shortened, incomplete or inappropriate dose of an antibiotic kills those bugs that are most susceptible to the drug but leaves alive those that have some resistance to it -- to reproduce and pass on their genetic resistance. Aided by persistent and widespread inappropriate use of antibiotics, the resistance to multiple drugs appears in some bugs, giving rise to superbugs.
Yes, we have the ability to engineer pharmacological weapons against these bugs, but let's not forget that microorganisms appeared on the earth millions of years earlier than human beings. Microbes have the ingenuity that keeps them a step ahead of us. Thus, as soon as antibiotics emerged, so did antibiotic resistance. Within a few months of the first extensive use of penicillin in 1940 -- the first antibiotic to treat infectious diseases in humans -- resistance to this drug was also reported. Ever since, the development of new antibiotics by humans has been followed by the development of mechanisms to counteract the drugs by the microbes.
Antimicrobial resistance also has enormous social and personal costs. When infections become resistant to first-line antibiotics treatment has to shift to second- and third-line drugs, which are nearly always much more expensive and sometimes more toxic as well. The drugs needed to treat multidrug-resistant tuberculosis (MDR-TB) are over 100 times more expensive than the first-line drugs.
In some countries the high cost is prohibitive, with the result that some of these cases can no longer be treated. Similarly, the emergence of resistance in HIV to currently effective drugs could destroy the hopes of survival for millions of people living with HIV.
Discovery, development and distribution of new antibiotics is a long, drawn out and expensive process. After investment of millions of dollars and years of research, when a new antibiotic becomes available, its misuse renders it ineffective in a very short time. This discourages the pharmaceutical industry from undertaking research and development that promises a very low return on investment. Thus, we are now at a stage where the discovery of new antibiotics has slowed to a crawl.
During the past 15 years, only two new classes of antibiotics have been discovered. The advent of antimicrobials had led to the hope that infectious diseases might become a thing of the past. Time has proven how misplaced this confidence was, and also demonstrated the survival skills of microbes, which should never be underestimated.
It is also erroneous to suggest that superbugs or multidrug-resistant bugs are prevalent only in developing countries. In this era of interdependence, rapid travel and globalisation, either everyone is at risk or no one. The burden of infectious diseases may be much higher in developing countries, but there are several superbugs that are widely prevalent in the developed world.
Methicillin-resistant Staphylococcus aureus (MRSA), a bacterium responsible for several difficult-to-treat infections in humans, is one example of the superbugs that are killing thousands of people in the developed world every year. One difference is that there are more efforts to contain these superbugs in resource-rich settings because of better surveillance systems and increased awareness.
The developing countries also need to take up this challenge and establish monitoring mechanisms and remedial actions at all levels. We should be quite clear that combating superbugs and antimicrobial resistance is a technical challenge that cannot be addressed by health administrators alone.
Misuse of antibiotics by prescribers and users have behavioural, educational, ethical and economical dimensions which demand concerted and sustained actions by all sectors of society. Weak pharmaceutical regulatory mechanisms in most developing countries also permit the availability of antibiotics of questionable quality and the unauthorised sale of these antibiotics.
We would do well to remember that this pressing problem goes beyond the health sector. It is estimated that half of the tonnage of antimicrobial production in North America and Europe is used in food-producing animals and poultry, largely for prophylaxis and growth promotion. This creates a "selection environment" for microbes, and is a further reason why rational use must be practiced everywhere and by everyone, from the livestock producer to the individual patient.
Preservation of the efficacy of the life-saving and precious resource of antibiotics cannot be taken lightly and left to a few individuals or experts. It is a global issue that requires global efforts. The time for sustained action is now, since we are slowly but surely moving towards a reversion to the dreadful pre-antibiotic era. If that happens, unacceptable mortality and morbidity due to untreatable infectious diseases will become the biggest obstacle to poverty alleviation, development, and global efforts to make the world a better and healthier place.
The writer is Regional Director, WHO Regional Office for South-East Asia, New Delhi, India.
E-mail: [email protected]
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