A game plan to win the coming fight against superbugs

We import more antibiotics to promote animal growth than treat people. AAP

We depend on antibiotics to treat what previously were fatal conditions. But the more we use them, the more the bacteria they fight become resistant to all the weapons in our arsenal.

Bacterial resistance to antibiotics (antimicrobial resistance) is a natural consequence of antibiotic use. This phenomenon, driven by natural selection, cannot be eliminated by managing antibiotic use alone.

To avert an impending health crisis we need to take new measures, such as changing clinical practice and focusing on antibiotic discovery and development.

Noting the seriousness of the situation, the World Health Organisation (WHO) recently released a policy to fight the spread of antimicrobial resistance.

We urgently need legislation that governs how antibiotics are approved as well as used in humans and animals, alongside better surveillance and diagnosis of infections to ensure continuing good health.

Why the fuss?

Superbugs are bacteria that are resistant to most antibiotics.

They are becoming big killers, causing more than 500,000 deaths in Europe and the United States each year. They cost health systems billions of dollars annually - $20 billion a year estimated in the United States alone.

Globally, infectious diseases are still the leading cause of death from disease and superbugs can potentially magnify their toll.

Superbugs include:

  • a strain of drug-resistant tuberculosis;

  • MRSA - a bacteria resistant to the antibiotic methicillin;

  • VRSA and VRE - bugs resistant to the antibiotic vancomcycin; and

  • NDM-1, which is resistant to almost every drug including carbapenems (a powerful group of antibiotics with broad-spectrum activity) and spreading like wildfire.

What can be done?

1) Antibiotic resistance is facilitated by inappropriate use of drugs, such as taking sub-standard doses or not finishing a prescribed course of treatment.

It is vital that patients are made aware of the importance of completing full courses. Also, fake antibiotics circulating in countries with unregulated medicine markets need to be addressed.

2) Poor infection prevention and control also encourage the development and spread of drug resistance.

Even simple things such as effectively washing hands to prevent the spread of infection are a step in the right direction.

3) An obvious threat we could immediately deal with in Australia is the continued use of antibiotics as growth promoters in animals.

These antibiotics are not used to cure sick animals, but are given to animals every day in food or water to maximise their growth.

Prescribing antibiotics in this manner - as a preventative or constitutively - and at low dose is a classical scientific move that induces resistance in bacteria.

In Europe, feeding antibiotics and related drugs to livestock for growth promotion was banned in 2006. This followed a 1998 ban on feeding antibiotics valuable in human medicine to livestock for the same reason.

The Australian government commissioned a review of antibiotic resistance and its importance in human and veterinary health in 1997.

Reporting in 1999, the commission found there was clear evidence for:

  • The emergence of resistance in animals following antibiotic use;

  • The spread of resistant bacteria from animals to humans;

  • The transfer of antibiotic-resistant genes from animal bacteria to human pathogens; and

  • Resistant animal bacteria causing disease in humans.

The committee recommended key steps to prevent the impending health crisis, and noted that many other countries had enacted legislation to stop the practice of giving animals antibiotics.

The report was published 12 years ago, and while the Australian Pesticides, Veterinary Medicines Authority (APVMA) has banned one particular class of antibiotics (fluoroquinolones) for use as a growth promoter, many antibiotics remain in the food chain.

In fact, we still import far more antibiotics for use as growth promoters - about 450 tonnes a year - than we do for treating humans - around 230 tonnes a year.

4) Only four new chemical classes of antibiotics have launched in the last 40 years - linezolid (2000) and daptomycin (2003) for systemic infections, mupirocin (1985) and retapamulin (2007) for topical infections.

Between 10 and 12 new antibiotics became available in the decade prior to this.

Pharmaceutical companies have obviously walked away from antibiotic research - there were 18 active in 1990 but only five by 2011. We need more funding for biotechnology and academic researchers to fill the pipeline.

Governments could also adopt measures easing the requirements for Phase III clinical trials. This would encourage pharmaceutical companies to re-start work on developing new antibiotics.

Call to action

New antibiotics are mainly derived from natural products produced by bacteria over billions of years of evolution. They represent a finite and precious resource that we are squandering over the course of a few generations.

Without immediate action, one of the seminal discoveries of the twentieth century that has saved hundreds of millions of lives will soon be lost to us.

A lack of government commitment to address this issue, together with a diminishing arsenal of new antibiotics to treat infections means we now are facing a situation where the number of available options are rapidly dwindling.

Professor Matthew Cooper will appear on SBS ONE tonight at 7.30 pm on Insight - Superbugs