Today is World Health Day, and the World Health Organization is using the occasion to draw attention to a serious global health problem: the rapid spread of bacteria resistant to antibiotics. The development and widespread use of antibiotics counts as a public health triumph, as infections that once routinely killed large numbers of people became much easier to treat. That triumph can be undone, though. WHO Director-General Margaret Chan warns, “In the absence of urgent corrective and protective actions, the world is heading towards a post-antibiotic era, in which many common infections will no longer have a cure and, once again, kill unabated.”
Those who’ve become infected with an antibiotic-resistant bacteria probably already know that we have a problem, because their illnesses tend to be longer and more severe. Some of these patients are cured by other antibiotics, which are often more expensive and can bring worse side effects. Some die.
Maryn McKenna – author of the book Superbug and one of the top experts on this issue – runs through some of the disturbing numbers on the diseases that have become resistant to both first-line and last-resort drugs. For an even more unsettling read, check out her recent Scientific American article on two new resistance genes that have been found in bacteria carried by US patients.
Antibiotic resistance would emerge even if antibiotics were used sparingly. With our excessive use of these drugs, though, antibiotics are losing their effectiveness at an alarming rate. Patients want antibiotics from their doctors, even if their diagnosis is a virus that won’t respond; many doctors just write the prescriptions rather than try to convince their patients it’s a bad idea. And whether the antibiotic is prescribed appropriately or not, some patients will fail to follow the dosage instructions and allow the hardiest of the bacteria they’re carrying to survive.
Treating human infections isn’t the only use of antibiotics, though. Back in 2001, the Union of Concerned Scientists estimated that 24.6 million pounds of antimicrobials are used in livestock for non-therapeutic purposes each year – that is, food animals are getting dosed for reasons like growth promotion, not to cure specific infections. The FDA recently reported that livestock producers used nearly 29 million pounds of antimicrobials in 2009, so UCS’s estimate was probably not far off. Many of these drugs are also used in humans, so their extensive use in livestock is contributing to the problem of bacterial resistance to antibiotics on which we rely.
The FDA is promoting the “judicious use” of antibiotics through voluntary measures, and in March US Representative Louise Slaughter re-introduced the Preservation of Antibiotics for Medical Treatment Act, which would phase out the non-therapeutic use in livestock of medically important antibiotics. The WHO is also promoting a set of policy solutions to all countries:
- develop and implement a comprehensive, financed national plan
- strengthen surveillance and laboratory capacity
- ensure uninterrupted access to essential medicines of assured quality
- regulate and promote rational use of medicines
- enhance infection prevention and control
- foster innovation and research and development for new tools.
The last one – fostering innovation and R&D for new tools – is important but will likely require some big changes in how drugs are developed. McKenna reports in her Scientific American article that the current pipeline isn’t promising:
We might be able to research our way out of this dilemma with yet another new class of antibiotics–at least until the bacteria catch up once again. But with no new medications in the 10-year pipeline capable of dispatching these latest superbugs, we may have to live with the risk of many kinds of untreatable infections for an uncomfortably long time.
“It has been hard to discover new compounds that work against gram-negatives and are not toxic to people,” says David Shlaes, a physician and drug-development consultant and author of Antibiotics: The Perfect Storm (Springer, 2010). “When you think about it, what you are trying to do with an antibiotic is trying to kill something within us, without hurting us. It is challenging.” The last new antibiotic licensed for gram-negative infections was doripenem, a carbapenem that was approved by the Food and Drug Administration in 2007.
The Economist points out that investing in developing new antibiotics is not financially attractive to drug companies because the drugs will only be taken by a relatively small number of people for relatively short periods of time. Other financial incentives – like tax credits, guaranteed markets, and prizes – might encourage more investment in R&D for antibiotics to treat infections resistant to current treatments.
As individuals, we can use antibiotics responsibly (when needed for an infection and according to the prescriber’s instructions) and try to buy meat, eggs, and dairy products from producers who don’t use antibiotics for non-therapeutic reasons. And we should also be aware that the bacteria we encounter day to day – and especially when we’re in hospitals or nursing homes – might be resistant to antibiotics. I’m going to go wash my hands now.