An interview with the authorsPublished May 2013
The NIH Superbug
A reminder of things to come?
By Lauren Weisenfluh
Published October 5, 2012
The infamous National Institutes of Health (NIH) superbug— Carbapenem-resistant Klebsiella pneumonia, KPC—has claimed its seventh victim. As clinicians scramble to contain the outbreak (which has infected a total of 19 patients), many are scratching their heads, avoiding the terrifying question: are we to blame for this unprecedented level of antibiotic resistance?
Yes, yes we are.
Our apparently harmless every-day actions are at fault. Patients fail to finish their prescription antibiotics. Livestock routinely crunch down antibiotics with their meals. Commuters casually wring their hands with liquid-goo that kills up to 99.99 percent of all subway-obtained germs.
These actions promote evolution in real time. We are unintentionally selecting for mutant bacteria that withstand antibiotic treatment, bacteria that turn around and father more antibiotic-resistant progeny. We are seeing evolution at work, affecting disease burden as we speak, made possible by bacteria’s extremely rapid reproductive rate.
The result: the KPC superbug.
The good news is that while it may be too late for the KPC superbug, we can still prevent other bacteria from getting to this point.
Take methicillin-resistant Staphyloccocus aureus (MRSA). MRSA infections have skyrocketed—no—throttled past the sound barrier over the past thirty years: from two percent of all S. aureus infections methicillin-resistant in 1974 to 64 percent in 2004, resulting in 19,000 United States (U.S.) deaths in 2005.
Back in 1940, S. aureus was typically treated with penicillin. When S. aureus became resistant to penicillin, scientists developed methicillin for treatment.
Methicillin seemed to solve the problem—for about a year. Then, in 1961, the very first case of MRSA was identified in Britain. Another seven years later, the U.S. identified its very first case of MRSA. Another round of drug development began.
Certainly, the story doesn’t stop there. The list of ineffective treatments is long and varied. It presently includes an entire class of penicillin-like antibiotics.
And the list continues to grow.
What’s worse still: many hospitals are endemic sites of MRSA. Most MRSA infections are nosocomial, meaning that they originate in hospital settings. These infections are preventable by simple acts, such as hand washing and wearing gloves. Yet, MRSA is a constant problem within hospitals.
Tuberculosis is yet another example of antibiotic resistance mismanagement. Extensively-drug resistant (XDR) tuberculosis (TB) has emerged in 64 countries, reports the World Health Organization (WHO). Treatment of MRSA-TB requires second-line drugs.
Treatment of XDR-TB requires chemotherapy.
That’s expensive. A single U.S. hospitalization of XDR-TB costs $483,000 to treat—about twice the cost of treating MDR-TB. Moreover, mortality among XDR-TB patients is about the same as TB mortality before antibiotics. And for the past 40 years, no new antibiotics for TB-treatment have been discovered.
Tuberculosis is not the only example. Malarial drugs, including chloroquine and sulfadoxine-pyrimethamine, have already become ineffective in some malaria-endemic areas. Drug-resistant gonorrhea has also emerged.
Not much is certain in this game of evolution-roulette, except for one: drug development is not a long-term cure. Scientists may be clever, but natural selection trumps all.
Solutions are simple, made complex by human behavior.
Regulators need to cap the amount and type of antibiotics fed to livestock. Luckily, the U.S. is moving in the right direction on this count. In January 2012, U.S. regulators placed a restriction on the use of cephalosporins in livestock, citing concern over antibiotic resistance.
Worn by the trials of illness, patients often walk into the doctor’s office expecting antibiotics. Patients need to know when to use antibiotics, need to know that you can’t treat a virus, nor the flu, with antibiotics. After all, estimates suggest that a third of the U.K. population believe that antibiotics can treat coughs and colds—neither of which are bacterial.
Antibiotic treatment regimens need to be finished. Making the problem even more complex: the majority of non-finishers know that they should finish their course, yet fail to do so because they start to feel better after a few days of antibiotic treatment
Physicians also jump the gun, prescribing antibiotics to avoid a missed case—even without a positive bacterial culture. Surely, these actions have patients’ short-term interests at heart. But the long-term consequences are disastrous.
Clearly this battle requires everyone’s cooperation—not just the U.S. After all, Azerbaijan and Moldova are currently considered the multi-drug resistant TB hot-spots of the world. MRSA was first reported in England. The world needs to be behind it. But who says that we can’t lead the way?
Otherwise, we can all say “hello, superbug” to KPC and many more to come.
Edited by Karestan Koenen and Abdul El-Sayed. Additional research by Larkin Callaghan.