Sean Philpott: Fighting the Invincible Foe
Unbeknownst to most, mankind is at war with an invincible foe. Their numbers are legion and few if any of the weapons we have in our arsenal can stop them. I'm not talking about the rampaging zombie hordes shown on The Walking Dead or in trailers for the upcoming movie World War Z. Rather, I'm talking about antibiotic resistant bacteria.
Earlier this month, officials at the CDC, the US Centers for Disease Control and Prevention, raised concerns about a new family of drug-resistant bacteria that were spreading through hospitals across the country. This particular 'superbug' -- tongue-twistingly called carbapenem-resistant Enterobacteriaceae but informally named CRE -- is largely untreatable.
Without safe and effective antibiotics to treat patients, doctors must resort to alternative methods to cure patients with CRE. This may involve the use of older and more toxic drugs that may cause kidney or liver failure. Alternatively, surgeons may be forced to excise infected tissue or amputate infected limbs. Overall, CRE kills about half of those infected.
Thankfully, infection with this superbug is still rare. Enterobacteriaceae infections occur primarily in very sick patients confined to hospitals and nursing homes, and less than 5% of infections by this class of bacteria are caused by drug-resistant strains. But the number of CRE infections is growing rapidly.
Public health officials estimate that the number of cases has quadrupled in the last decade, but that is likely an underestimate. Smaller hospitals and nursing homes often lack the laboratory expertise to properly test for antibiotic resistant-strains of Enterobacteriaceae, so many CRE infections may go unidentified. Moreover, there is no national requirement that hospitals and nursing homes report cases to the CDC, and only a handful of states have local reporting requirements.
No one is sure how widely these bugs have spread. However, cases have been seen in 42 states and CRE infections are now endemic in many larger communities (including New York).
CRE is also not the only superbug that threatens us, though it is currently the deadliest. Other drug-resistant strains of bacteria are becoming commonplace, including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE) and multidrug-resistant Mycobacterium tuberculosis (MDR-TB). Unlike CRE, these other superbugs are not limited to hospitals and nursing homes. They are found in the community and can infect otherwise healthy individuals. MRSA alone is now estimated to kill around 20,000 people every year in the US.
Sadly, this grave public health threat is one of our own making. Overprescribing and misuse of antibiotics are the main reasons that these superbugs have emerged. Antibiotics like methicillin and vancomycin readily kill most bacteria, but an extremely small percentage of these microorganisms are naturally resistant. Whenever an antibiotic is used, the sensitive bacteria die off but the resistant bacteria thrive. Eventually, the resistant bacteria take over. This is why antibiotics should only be used sparingly.
Unfortunately, antibiotics are not used sparingly. Most people expect their doctor to prescribe antibiotics whenever they feel sick, be it strep throat or the flu. In many of these cases, however, an antibiotic is neither needed nor appropriate. For example, antibiotics do not work against viruses. So treating the flu with a 'Z-pack' is largely ineffective. But many doctors will prescribe it anyway, if only for the patient's piece of mind.
Modern agricultural practices are also to blame, particularly factory farming of livestock in order to satisfy Americans' desire for cheap meat, milk and eggs. Cattle, swine and poultry are often housed and raised in crowded conditions like feedlots, where bacterial infections can spread rapidly and decimate an entire herd. So, it has become routine practice to add antibiotics to the feed and water supply to prevent the spread of disease.
So what needs to be done to combat this threat? There needs to be a concerted effort at the federal, state and local level to track antibiotic resistant infections; reporting of cases to the CDC and State Departments of Health should be mandatory. We can't fight the enemy unless we can find the enemy.
Moreover, the federal government should provide financial incentives for pharmaceutical companies to develop new antibiotics. Despite the threat that antibiotic-resistant bacteria pose, there are few new drugs in development. It is simply not cost effective for a company to spend billions developing a new antibiotic when the bacteria adapt so quickly. We need more weapons to combat this foe.
Finally, educating the public is important. As patients, we all can stop asking our doctor to prescribe us an antibiotic every time we have the sniffles. As consumers, we can insist on buying free-range and antibiotic-free meat, milk and eggs even if they cost a little bit more. This is a fight that can be won only if we all contribute to the war effort.
A public health researcher and ethicist by training, Dr. Sean Philpott is Director of Research Ethics for the Bioethics program at Union Graduate College-Icahn School of Medicine at Mount Sinai in Schenectady, New York. He is also Acting Director of Union Graduate College's Center for Bioethics and Clinical Leadership, and Project Director of its Advanced Certificate Program for Research Ethics in Central and Eastern Europe.
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