Without effective antibiotics, much of modern medicine would not be possible. The treatment of cancer, the care of premature babies and even the most common surgical procedures would not be possible. Yet as each day passes, we move closer to a post-antibiotic era. The severity of the problem, which has rendered many of the strongest antibiotics useless, has prompted the World Health Organization to devote this year's World Health Day to antimicrobial resistance.

"The message on this World Health Day is loud and clear. The world is on the brink of losing these miracle cures," says Dr Margaret Chan, Director-General of the World Health Organization, in a dramatic video message posted on YouTube (watch above or click here to see), to mark World Health Day. "More and more essential medicines are failing. The world is heading towards a post-antibiotic era, in which many common infections will no longer have a cure and once again, kill unabated." But as she explains, "the responsibility is entirely in our hands".

The numbers are striking. Each year, 25,000 people in the EU die from bacterial infections that cannot be treated with antibiotics. Last year 440,000 cases of multi-drug resistance tuberculosis were detected and reported in 69 countries. The malaria parasite has acquired resistance to the most powerful antibiotic artemisinin and there is currently a large scale project to contain the spread of this from the Thai-Cambodian border to Africa, where millions of lives would be at risk. Resistance to antiretrovial drugs used to treat HIV is also emerging. Action is needed now to prevent a global health crisis on a catastrophic scale.

What is antimicrobial resistance?

Antimicrobial resistance is a naturally occurring phenomenon. Over billions of years, bacteria have evolved a survival mechanism which enables them to develop a resistance to most antibiotics. As a result, even the most recently approved and most effective drugs will gradually decline in efficacy. In addition, with the extensive clinical trials required before a drug is approved by regulatory bodies, resistant strains emerge even before the drugs are approved. Linezolid, an antibiotic developed to combat MRSA, was approved by the US regulators in 2000. The first linezolid-resistant strains had been discovered in patients a year before.

However, the looming global health crisis is the result of an acceleration in drug resistance caused by the inappropriate use of antibiotics. The widespread over-prescription, mis-prescription and non-compliance of antibiotics, often due to time-consuming diagnostic tools, are the main factors that have led to drug resistance as well as counterfeit and drugs of poor quality.

The rampant and unnecessary use of antibiotics, often bought over the counter without the need for a prescription from a doctor, along with unsanitary and crowded environments provides fertile ground for the emergence of drug resistance in countries such as India. Last summer, in a study published in the Lancet, researchers discovered the so-called New Delhi superbug, NDM-1, in India, which is resistant to carbapenem, one of the most powerful antibiotics. Since then, it has been detected in numerous countries across the world.

Another study published in the Lancet Infectious Diseases today, by the same lead author, shows that the NDM1 has spread to New Delhi's drinking water supply, which means that millions of people could be carrying the superbug.

However, the widespread abuse of antibiotics is not just confined to developing countries where there is little or no regulation. France has one of the highest rates of antibiotic consumption in the world. In poor countries, the sale of counterfeit drugs is commonplace. This is a global problem as borders offer no protection thanks to modern travel. A superbug can travel across the world in very little time.

The second main problem with drug resistance that WHO higlights today is that few antibiotics are being developed by the pharmaceutical industry. "We need to ensure a vibrant, diverse, long-term pipeline of effective antibiotics," Dr John Rex, Vice President, Clinical Infection, at AstraZeneca, told Scientific American. "However, we are not seeing sufficient development of new and novel classes of antibiotics to treat infections," he added. The lack of financial incentive along with scientific complexity and regulatory hurdles are the main challenges that hampers the efforts of the pharmaceutical industry in the development of new antibiotics. "The discovery of new antibiotics is not a simple task," Dr Rex explained.

Progress depends on sustained efforts by industry over a period of many years, combined with the existence of, as well as scientific progress by, diverse groups of trained scientists within academia and industry. Much of the research infrastructure required for this process was lost during the 1990s when, mistakenly, there was a sense that new antibiotics were not needed, said Dr Rex.

Astra Zeneca and GlaxoSmithKline are the only two large pharmaceutial companies that invest in the development of new antibiotics. Astra Zeneca invests and develops agents active against highly resistant Gram-positive bacteria (MRSA), resistant Gram-negative bacteria and resistant strains of tuberculosis. But many experts warn that, given the pace at which drug resistance is emerging and the time it takes to develop new drugs, this is not enough.

What can be done to curb the problem of drug resistance?

Today, WHO has launched a world wide campaign to highlight drug resistance and to mobilize action to curb the problem and to encourage the development of new antibiotics. The six point policy package is aimed at everyone and especially to get "governments and their drug regulatory systems on the right track, with the right measures, quickly." These include strategies to encourage governments to develop and implement strong policies, strengthen surveillance and laboratory capacity, to promote rational use of antibiotics, improve infection control and encourage research into new drugs.

Drug resistance is a global problem, which affects all regions of the world, and the solution involves everyone: patients, doctors, hospitals, government, industry, to ensure that antibiotics are used properly and that new drugs are developed. "There should be no borders to action," said Professor Didier Pittet, Director, Infection Control Program, University of Geneva Hospitals and Faculty of Medicine, Geneva, who likened the problem of drug resistance to global warming.

WHO's slogan, "No action today, no cure tomorrow," highlights the problem simply. Too little is being done to regulate the appropriate use of antibiotics to extend shelf life, and too little is being invested, both in terms of finance and expertise, in the development of new drugs. "The world needs to understand that we are dealing with time bombs," Dr Mario Raviglione, Director, Stop TB Department, World Health Organization, told Scientific American. Time is running out.

About the author: Gozde Zorlu is a science writer. She has just returned to London from working at the World Health Organization's flagship publication, the Bulletin, also known as the International Journal of Public Health, in Geneva. Her work has also been published in the Guardian, Nature News and New Scientist. She studied the History, Philosophy and Social Studies of Science at University College London and then went on to train as a science journalist at City University, London. You can follow her tweets at @GozdeZorlu.

The views expressed are those of the author and are not necessarily those of Scientific American.

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