Don’t let the superbugs bite

But don't despair - we might be struggling but we are not beaten yet.

Evolution continues to be a bitch. Recently scientists gathered in Kensington, London, to have a good moan and to plan what can be done about it. “Superbugs and Superdrugs” is a great title for a meeting. Unfortunately the bugs seem to be more super than the drugs.

While that meeting went on, the US Centres for Disease Control and Prevention (CDC) issued a warning that we are entering a “nightmare” era. The CDC’s problem is a killer bacterium known as CRE, which is spreading in the US. Some strains of CRE are not only resistant to all antibiotics; they are also passing on that resistance to other bacteria, creating drug-resistant strains of E coli, for instance. On 11 March, Sally Davies, the UK government’s chief medical officer, asked the government to add the superbug problem to its “strategic risk register”, which highlights potentially catastrophic threats to the UK.

For a while, it all looked so good. When scientists discovered penicillin, then ever more weapons for our antibiotic arsenal, it seemed that bacteria had been defeated. The problem is, they fought back.

For all the worry over CRE, perhaps nowhere is this antibiotic resistance more evident than with tuberculosis. In the west, we won the war on TB so convincingly that receiving the BCG vaccine against it – once a waymark in British childhood – is no longer routine. Only in certain inner-city communities where migrant populations increase the likelihood of encountering the TB bacterium are children routinely immunised. However, in 2011, the World Health Organisation marked London out as the city with the highest TB infection rate in western Europe.

Many resistant bacteria originate in hospitals, where pharmaceutical regimes kill off the normal strains, making space in which bacteria that are naturally resistant can proliferate. Yet you can’t always blame the drugs. Research published at the end of February shows that drug resistance can arise even when the bacteria have never encountered a chemical meant to kill them.

In the study, E coli bacteria were made to suffer by exposing them to heat and restricting the nutrients in their environment. According to conventional wisdom, this should have kept proliferation in check – but it caused a spontaneous mutation that made the E coli resistant to rifampicin, one of the weapons in our antibiotic arsenal. What is worse is the observation that there was good reason for this mutation to arise: it made the stressful conditions more survivable. Bacteria with the mutation grew much faster.

Bacteria are survivors – if they can’t magic up a spontaneous mutation, they’ll pick one up in the street. A sampling of puddles in New Delhi showed that almost a third contain the genetic material that allows bacteria to produce an enzyme that destroys a swath of antibiotics. The NDM-1 gene is particularly evil. Its tricks include forcing itself into gut bacteria such as E coli that are incorporated into faeces; as a result, the resistant strains travel between hosts with ease.

Many infections involving a bacterium carrying NDM-1 are untreatable. GlaxoSmithKline is reportedly developing a drug to deal with it but it is years behind the curve. In the autumn, an EU project to mine the seabed for so far undiscovered antibiotics will start up, but it will take years for that, too, to bear fruit.

Let’s end on a positive note. Superbugs might be evolving in fiendish ways but they’re doing it blind and they’re up against evolution’s greatest invention – the human brain. We might be struggling but we are not beaten yet.

The EHEC bacteria. Image: Getty Images

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 25 March 2013 issue of the New Statesman, After God

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.