16/03/2012 13:18 GMT | Updated 16/05/2012 06:12 BST

Resistance To Antibiotics Could Spell 'End Of Modern Medicine As We Know It'

Antibiotics could soon become ineffective, making conditions harder to treat and minor ailments potentially fatal, the head of the World Health Organisation has claimed.

The director general of the WHO, Margaret Chan, warned that the widespread use of antibiotics has led to bugs becoming increasingly resistant to the drugs.

Speaking at the launch of a WHO book on the subject, she told a group of infectious disease experts that we were entering a “post-antibiotic era”.

She warned: “Things as common as strep throat or a child’s scratched knee could once again kill.

“Antimicrobial resistance is on the rise in Europe and elsewhere in the world. We are losing our first-line antimicrobials.

“Replacement treatments are more costly, more toxic, need much longer durations of treatment, and may require treatment in intensive care units.

“For patients infected with some drug-resistant pathogens, mortality has been shown to increase by around 50 per cent.

“A post-antibiotic era means, in effect, an end to modern medicine as we know it.”

The WHO book, The Evolving Threat of Antimicrobial Resistance – Options for Action, warns that “a crisis has been building up over decades, so that today many common and life-threatening infections are becoming difficult or even impossible to treat”.

It says “much stronger action worldwide” must be taken “to avert a situation that entails an ever increasing health and economic burden”.

According to the WHO, the powerful medicines that have been developed over the last few decades to treat diseases such as tuberculosis, malaria, HIV, influenza and many bacterial infections, will likely become ineffective in the future because of resistance, posing a worldwide health threat.

Drug resistance causes increased and prolonged illness, a greater risk of complications and higher death rates. Infections which are increasingly resistant to antibiotics are causing a heavy disease burden, particularly in developing countries.

The organisation blames the spread of resistant bacteria on unnecessary and inappropriate use of antibiotics.

What is antimicrobacterial resistance?

Also known as drug resistance, antimicrobial resistance occurs when microorganisms such as bacteria, viruses, fungi and parasites change in ways that render the medications used to cure the infections they cause ineffective, according to the WHO.

When the microorganisms become resistant to most antimicrobials they are often referred to as “superbugs”. This is a major concern because a resistant infection may kill, can spread to others, and imposes huge costs to individuals and society.

However, although Dr Chan says “the pipeline is virtually dry” in terms of new replacement antibiotics, she believes a number of actions can be taken to help the situation.

She says: “Much can be done. This includes prescribing antibiotics appropriately and only when needed, following treatment correctly, restricting the use of antibiotics in food production to therapeutic purposes and tackling the problem of substandard and counterfeit medicines."

Allergic asthma on the rise

A study at the University of British Columbia found that widely used antibiotics may increase incidence and severity of allergic asthma in early life.

The study’s author, UBC microbiologist Brett Finlay, said: “It has long been suspected that kids exposed to more antibiotics – like those in developed countries – are more prone to allergic asthma.”

He added: “Our study is the first experimental proof that shows how."

The researchers at UBC’s Department of Microbiology and Immunology and Michael Smith Laboratories examined how two widely used antibiotics – streptomycin and vancomycin – affected the bacterial “ecosystem” in the gut. They found that vancomycin profoundly alters the bacterial communities in the intestine and increases severity of asthma in mouse models.

The same antibiotics do not impact adult mice’s susceptibility to asthma, indicating that early life is a critical period of establishing a healthy immune system.

Modern societal practices, such as improved sanitation methods and widespread antibiotic use, are causing the disappearance of ancestral species of bacteria in our gut that may be critical to a healthy immune system,” says Finlay.

“Our study shows this is the case with certain antibiotics and allergic asthma, and the gut-lung connection is also consistent with observations that incidence of asthma has not increased significantly in developing countries where antibiotic use is less prevalent – and in turn, the gut flora is permitted to fully develop.”

Leanne Metcalf, Assistant Director of Research at Asthma UK, said in response to the research: “We know that early life is a crucial time for the immune system to develop properly to protect us against harmful things in the environment. In developed countries where we see lower levels of bacteria and infection because of modern cleaning and medical practices, we also see higher rates of asthma.

“This is because these practices encourage the immune system to become over-sensitive to substances in the environment that are not harmful, causing conditions like allergic asthma.

“Any information which helps us to understand how the way we treat infections in our children can influence their susceptibility to asthma and allergies, and how badly they are affected, is greatly welcomed.”