In 1674, Anton van Leeuwenhoek, could see bacteria through a microscope. Louis Pasteur, in 1865, founded the science of microbiology, and proved that most infectious diseases are caused by microorganisms. This became known as the 'germ theory' of disease. Alexander Fleming, discovered the mould, penicillin in 1928, which could kill many germs that caused infections. Fleming's discovery saved the lives of millions of people during the course of time. Without this drug many soldiers during World War II would have died from infections of the wounds. The discovery of penicillin led to the discovery of a whole lot of other antibiotics such as streptomycin. It was a great step forward in the history of medicine.

We live in an era of medical breakthroughs with new wonder drugs available to treat conditions that a few decades ago would have proved fatal. On this World Health Day 2011, WHO will launch a worldwide campaign to safeguard these medicines for future generations.

'Antimicrobial resistance' is the theme for this World Health Day, with the slogan, 'no action today, no cure tomorrow'. Antimicrobial resistance is the ability of a microorganism to survive when exposed to antimicrobial drugs. Genes can transfer this ability from one microorganism to another. Antimicrobial resistance and its global spread threaten the continued effectiveness of many medicines used today, while at the same time it risks jeopardizing important advances being made against major infectious killers. When the organisms become resistant to most antimicrobials, they are often referred to as 'Superbugs'.

At first all microorganisms were affected by sulfanilamide, and it was tagged a 'wonder drug'. Soon it become apparent that any microorganism capable of producing para-amino-benzoic acid (PBA) on its own could produce enough PBA to displace the sulfanilamide by the old law of mass action and proceed with synthesis. Later, after sulfanilamide had been around long enough, some microorganisms adapted to using it as their substrate and could remove it from solution. As a result sulfanilamide lost it punch.

About this time the fungi-produced antibiotics made their debut. Penicillin was extremely effective against many pathogenic bacteria. It was found that penicillin prevented the passage of glutamic acid into the cell. Those bacteria which could synthesize their own glutamic acid were unaffected by penicillin. Like sulfanilamide the presence of penicillin in large quantities stimulated the growth of bacteria which could metabolize penicillin.

Streptomycin was even more effective than penicillin. It reacted best under basic pH by blocking the entry of pyruvate into the citric acid cycle. There are other antibiotics of varying degrees of effectiveness. The most important aspect of antibiotics is that the presence of large quantities of antibiotics in use stimulates bacteria which not only are resistant but can degrade the antibiotic as a source of food.

Last year, the spread of the resistant bacteria in India, Pakistan and U.K. 'NDM-1', or New Delhi metallo-beta-lactamase, was first identified in a Swedish patient who had returned from New Delhi. Experts were concerned about the fact that the enzyme was found in one of the most commonly encountered bacteria in the human population, Escheridia coli, and that at least one in 10 of strains containing this enzyme appeared to be resistant to all known antibiotics.

The overuse, misuse and underuse of antibacterial drugs have led to an increase in and the emergence of resistance to these drugs. The food industry's increased use of antibiotics can lead to the further emergence of resistant bacteria and genes that threaten human health.

At present, 0.4 million resistant infections are estimated to occur every year in the European Union, leading to about 25 thousand deaths. Without new and effective antibiotics but with increasing resistance, society could return to the condition of a pre-antibiotic era, when a simple lung infection could kill a child, or when doctors could not fight meningitis. Multi-drug tuberculosis is another example of this emerging health threat.

Integrated monitoring of antibiotic consumption, prescriber and consumer education and regulation of use in communities and hospitals have shown that it is possible to contain antimicrobial resistance. However, even in well-regulated systems, such as those in Europe, resistance in some pathogens continue to increase unabated and problems remain in the use of antibiotics in animal food production can lead to the further emergence of resistant bacteria and genes that threaten human health.

WHO's Patient Safety Programme, the 2001 initiative, provided a start for some countries in tackling the problem. One of the challenges government face is enforcing laws banning over-the-counter sales of antibiotics. This is particularly difficult in low-to-middle income countries where there are often no doctors to prescribe medicines but people need to get the drug somehow. Children in Africa, Asia and Latin America suffering from pneumonia, meningitis or blood stream infections are often given old drugs rendered ineffective by resistance since they are the only available treatment options.