1. Most people don't really understand what "antibiotic resistance" is – and that's a huge problem.
You'd be forgiven for not knowing exactly what scientists mean by antibiotic resistance, because it turns out that very few people understand what's going on. What it means is bacteria becoming immune to the drugs we use to kill them.
But a recent investigation by the Wellcome Trust reported that almost no one really understands the problem or how serious it is.
2. We are on the edge of a "post-antibiotic era", according to scientists.
A new report in the Lancet Infectious Diseases journal says bacteria are becoming resistant to colistin, an antibiotic usually thought of as a "last resort". The resistant bacteria were found in both humans and animals in China.
These "superbugs" – others include the notorious MRSA – are going to become more common and ever harder to treat. But that's only a small part of the problem. It has been suggested that if we don't take steps very quickly, it could mean the end of modern medicine.
3. It could mean the end of most cancer treatments.
Chemotherapy and radiotherapy, two of the most common treatments for cancers, both cause heavy damage to patients' immune systems, our body's own defences against infection. "The consequences of suppressing immune systems is that, inevitably, people get infections," says Dr Luke Moore, a doctor at Imperial College, London.
"At the moment we can fight those infections with antibiotics, until the immune system is working again, but the cupboard is getting barer. It's harder to find drugs that will fight those inevitable infections."
4. It could mean the end of life-saving transplant operations.
Heart, lung, liver, and kidney transplants – and even face and womb transplants – are increasingly common. But to prevent the transplanted organs being rejected, the patients take drugs to deliberately suppress their immune systems, leading to the same problems as with the cancer treatments. "The logical conclusion is that we will reach the stage where we won't be able in good conscience to carry out those heart transplants, or to give chemotherapy," says Moore. "We can't knowingly do harm."
5. It could lead to a huge jump in deaths in childbirth.
"About a fifth to a quarter of births in the UK are by caesarean section," says Moore. That is, the mother's abdomen is cut open and the baby lifted out. Often it's done because it would be dangerous for the mother to give birth naturally.
Sometimes mothers get infections afterwards. "The post-operative infection rate is not well known, but it's probably between 3% and 5%," says Moore. At a conservative estimate, that's about 4,000 women per year in Britain.
Most of those bugs are picked up outside hospitals, and at the moment most drug-resistant bacteria are found inside hospitals. But that is changing rapidly. "Resistant bugs will soon be out in the community," says Moore. "There will be huge complications further down the line – five or 10 years."
6. It could make routine surgery too dangerous to carry out.
For the same reason that caesarean sections will become more dangerous, all other surgeries – even the most minor-seeming – are getting riskier. "I've just had surgery on my hip," says Prof Nigel Brown, the president of the Microbiology Society. "The reason I've been keen to get it done quickly is that it's rapidly getting harder."
Surgeons use antibiotics "prophylactically", he says – that is, to prevent patients from getting an infection, rather than to treat one. As antibiotics become unusable, it will become impossible to prevent patients from getting infections. Eventually, everyday procedures such as appendectomies, hip replacements, and knee repairs – let alone open heart surgery – will be too dangerous to carry out.
7. It's happening amazingly fast.
Drug-resistant infections are a perfect example of evolution in action. A course of antibiotics will kill almost all the bacteria it targets. But the ones that survive will tend to be the ones that are hardest for that drug to kill. They will reproduce, and the next generation of bacteria will tend to be slightly more resistant to that drug than their parents were. And because bacteria reproduce so quickly – several times an hour, in some cases – the evolution happens fast.
"When I was starting out, in the 1970s, the first drug-resistant strain of gonorrhoea appeared," says Brown. "Now, we're probably a few years away from gonorrhoea being completely untreatable. It's happened in the space of 40-odd years."
Moore says he is already struggling to treat infections in immunosuppressed people – the cancer or transplant patients. "The problem is in my face right now."
8. Patients also demand antibiotics from their doctors when they don't need them.
"Colds and flu are caused by viruses, which don't respond to antibiotics," says Brown. Viruses are different from bacteria, and antibiotics only kill bacteria. So if you take antibiotics for your cold, it won't make you better, but it will make any bacteria that are in your system (and there are always trillions) resistant to that antibiotic.
But the Wellcome Trust found that almost no one realises this. Most people think antibiotics are for when you're really ill. One person told the researchers: "If I felt really bad [and the doctor didn't give them to me] I'd ask to see another doctor. You know your own body."
People pester their doctors for antibiotics when they don't need them; the doctors give the antibiotics; and the antibiotics slowly become less useful because of it.
We also have to make sure that the millions who don't have access to them get them. "Here in the West we're very lucky because we have access to all these advanced antibiotics," says Moore. "Globally, more people are dying from lack of access to basic antibiotics than are from resistant ones."
9. Most people think that it's the patient, not the bacterium inside the patient, that's becoming resistant, but the opposite is true.
What that means is that patients often don't finish their course of antibiotics, thinking – reasonably enough – that if they take less of the drug, their bodies will develop less resistance to antibiotics. But in fact, they should be taking it all to be sure of wiping out all the bacteria and avoiding a few hardy ones surviving and spreading their resistance to the next generation.
"We don't know how big a problem [not finishing a course of antibiotics] is," says Moore. "But we think it's the worst thing that patients can do in terms of generating resistance." He says that "if you take your course as prescribed, you'll probably generate very little resistance in the bug you're treating".
10. It's not just overprescribing in humans. More than 50% of antibiotics worldwide are used on animals.
"Agricultural antibiotics are heavily used – if one cow looks sick, they dose the whole herd," says Brown. "It's the equivalent of treating the entire street if little Johnny at No. 14 has an infection."
Slurry ponds full of the animals' excrement are then swimming in bacteria and antibiotic – perfect breeding grounds for resistant bacteria. "And bugs can easily jump from animals to cause disease in humans," points out Moore – just look at swine flu and bird flu.
11. It's getting harder to come up with new antibiotics…
All the easy-to-find antibiotics have pretty much been found. "We've used all the low-hanging fruit, all the easy avenues," says Moore. The first antibiotic, penicillin, was grown literally by accident. That will never happen again.
Slightly more promisingly, though, new methods have been discovered. Moore says that in the last couple of years, a new technique for growing bacteria – almost all antibiotics are derived from bacteria – has been developed, which allows scientists to grow species which were impossible to keep in the lab before. That could be an avenue to some new discoveries.
12. …and besides, people aren't trying that hard, because antibiotics just don't make that much money.
"A new antibiotic compound can cost literally billions to get to market," says Moore. "For a drug company, a new antibiotic which someone takes for a week is just less economically worthwhile than a drug for blood pressure which someone will take for their whole life."
This is – obviously – a problem. The question is how we can "enthuse" pharmaceutical companies about making new antibiotics, he says. It may involved government subsidies or other incentives.
13. Once bacteria become resistant to an antibiotic, it might be decades before it can be used again.
There has always been one glimmer of hope in all this. Resistance to antibiotics is costly to bacteria. "Any excess gene [such as one giving resistance to a drug] carries a cost," says Moore. If there's none of that drug around, then non-resistant bacteria will reproduce faster and eventually squeeze the resistant ones out out.
That means that "we might be able to get on top of it, by using different antibiotics at different times", says Brown. "The world uses one antibiotic for some years, and then when bugs gain resistance to it, it can stop and use a different one."
But it may not be a quick fix. "There are two schools of thought on this," warns Moore. "The one I subscribe to is that some bacteria … can remain resistant to drugs which haven't been used for decades."