There are no bacteria in Mars

At the end of his 1898 novel The War Of The Worlds, HG Wells has his narrator describe for us the ultimate downfall of the Martian invader: “slain by the putrefactive and diverse bacteria against which their systems were unprepared....slain after all man’s device had failed, by the humblest things that God in His wisdom had put upon this earth.”

It seems in 2012, those same ‘humblest things’ could prove our undoing in a turn of events that the Bromley science fiction pioneer would almost certainly appreciate for its irony.

When the Director-General of the World Health Organization (WHO), Dr Margaret Chan told an audience in Copenhagen on 14 March that antimicrobial resistance (AMR) could mean "an end to modern medicine as we know it", she wasn’t exactly letting the cat out of the bag.

The seriousness of the problem has long loomed large in the minds of health professionals around the world. The over-use of antibiotics has led to a situation where “many other pathogens are developing resistance to multiple drugs, some to nearly all,” said Chan, delivering the keynote address at the conference on Combating Antimicrobial Resistance: Time For Action.

The problem, in a nutshell, is best characterised in Chapter 1 of The Evolving Threat Of Antimicrobial Resistance, published earlier this year (2012) by WHO: “Bacteria which cause disease react to the antibiotics used as treatment by becoming resistant to them, sooner or later. This natural process of adaptation, antimicrobial resistance, means that the effective lifespan of antibiotics is limited. Unnecessary use and inappropriate use of antibiotics favours the emergence and spread of resistant bacteria. 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, sometimes turning a common infection into a life-threatening one.”

“Hospitals have become hotbeds for highly-resistant pathogens, like MRSA, ESBL, and CPE, increasing the risk that hospitalization kills instead of cures,” Chan told her Copenhagen audience. And the good news just kept coming: “If current trends continue unabated, the future is easy to predict. Some experts say we are moving back to the pre-antibiotic era. No. This will be a post-antibiotic era,” said Chan.

“In terms of new replacement antibiotics, the pipeline is virtually dry, especially for gram-negative bacteria. The cupboard is nearly bare,” she warned. The Director General set out the harsh reality of the situation likely to face us in a world without the benefit of antibiotics: “A post-antibiotic era means, in effect, an end to modern medicine as we know it. Things as common as strep throat or a child’s scratched knee could once again kill.”

But while antimicrobial resistance is beginning to create major problems in the developed west, the problem in the developing world is always more acute. From the 12 million cases of tuberculosis diagnosed worldwide in 2010, WHO estimated that 650,000 involved multidrug-resistant TB strains. Treatment of MDR-TB is extremely complicated, typically requiring two years of medication with toxic and expensive medicines, some of which are in constant short supply. Even with the best of care, only slightly more than 50% of these patients will be cured.

Surveillance of usage is essential to getting a good understanding of anti-biotic usage worldwide in order to make informed decisions and develop effective responses to the crisis. Currently surveillance is patchy. This lack of consistency is being addressed but requires both resources and political will.

It may also be worth noting that WHO has flagged up concerns about anti-biotic usage in animal husbandry. “A substantial proportion of total antibiotic use occurs outside the field of human medicine and is probably a major contributor to the overall problem of emerging AMR.”

The issue really becomes problematic when AMR strains are introduced to humans through the food chain. “Antimicrobial use in food-producing animals and in aquaculture very often involves large-scale use for growth promotion and mass prophylaxis. Resistant pathogens found in food products can cause infections in humans that can be difficult to treat.”

Add this to the structural problems of the developing world. “Many countries are crippled by lack of capacity, including laboratory, diagnostic, quality assurance, regulatory, and surveillance capacity, and control over how antimicrobials are obtained and used,” said Chan. “Good public health practices are undermined by utter poverty. When resources are extremely limited, will a doctor use precious money to treat as many patients as possible, or invest in diagnostic tests?”

HG Wells thought that the Martians were defeated because “there are no bacteria in Mars” and that “by the toll of a billion deaths, man has bought his birthright of the earth and it is his against all comers.”

Maybe we were the Martians after all.