How Do Hospitals Stop the Spread of Drug-Resistant Superbugs Like C. Auris?

By ripping out floor tiles, reconfiguring pipes, and maybe deploying a hydrogen peroxide–spraying robot. Plus, a lot of bleach.

Medical professionals wash their hands.
Thorough and careful hand-washing can go a long way to keeping pathogens from running amok.
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On Saturday, the New York Times published a fascinating and anxiety-inducing article about the rise of an antifungal-resistant yeast called Candida auris in hospitals around the world. Patients with weakened immune systems are particularly susceptible, and once the fungus hits, infection spreads through their bloodstreams and causes fever and chills. Nearly half of people sickened by it die within 90 days, according to the Times, though it’s unclear if they are killed by the pathogen itself or by the diseases and conditions that landed them in the hospital in the first place. C. auris can also survive for weeks outside a patient—on sinks and mattresses, door knobs and bedside tables. To eradicate it after one patient died, a hospital in Brooklyn even “had to rip out some of the ceiling and floor tiles” in his room. How often do hospitals have to take such extreme steps to stop the spread of these drug-resistant superbugs?

Fortunately, very rarely, but when they do, the steps required can be expensive and exacting. According to the CDC, hospitals can often manage outbreaks by simply paying more attention to cleaning the environment and equipment around a patient. Medical experts know how to kill pretty much everything we encounter with disinfectants. The hospital’s standard quaternary ammonium compound—a common antimicrobial cleaner that kills many bacteria, fungi, amoebas, and viruses—is used for everyday cleaning and works most of the time. For the viruses (such as noroviruses) and bacteria (such as the very-long-living Clostridioides difficile) that survive, the hospital can use a bleach-based cleaner or other disinfectant known to kill specific organisms.

The concern in infectious outbreaks is generally that we will encounter a strain of a familiar bacteria or fungus that has developed a drug resistance that makes it hard to kill once it’s settled in a patient’s body. Hospitals are, unfortunately, one place a patient is more likely to encounter an antibiotic-resistant strain of something. They are, after all, where a large amount of antibiotics are used. That becomes particularly troublesome when paired with the long life span and sturdiness displayed by hardier microbes such as C. auris and C. difficile. While most pathogens die when left without a host, these can survive for weeks or months.

When hospitals know they have encountered an infection that can jump easily from patient to patient, they take crisis-level precautions. They isolate patients and prevent staff who treat them from caring for others. They hold meetings for medical and cleaning staff to train them on the specific rules for the specific microbe. They require visitors and staff to don gloves, gowns, and masks while in the patients’ rooms and become extra vigilant about ensuring no one leaves without washing their hands. (Thorough and careful hand-washing can go a long way to keeping pathogens from running amok.) Depending on the type of contaminant, they may also place patients in a ventilated room that doesn’t allow air to circulate into the rest of the hospital.

In extreme circumstances, like this C. auris outbreak, hospitals may be forced to tear apart rooms to get to where the microorganisms may be living. Typically, hospitals are only forced to discard more easily movable objects: infected mattresses or linens (as in a particularly tragic outbreak of Mycobacterium abscessus in a New Orleans pediatric hospital) or tools and other smaller sources of infection. In one case in the 1970s, a green liquid soap used to clean skin for IV insertions had been contaminated with the bacteria Pseudomonas stutzeri. In a much more recent case, the Food and Drug Administration traced two types of fungi, including Aspergillus, the most common cause of fatal fungal infections, to drug vials given to six patients in an experimental study.

It’s not unheard of for a hospital to have to tackle plumbing more aggressively. Especially in older buildings, bacteria cling to and flourish in sinks and pipes. When three people died in an outbreak of Legionnaires’ disease at the University of Wisconsin’s hospital in Madison last year, the hospital found the bacteria in its pipes and, like others in the same situation, simply pumped chlorine into the water. In other cases, the pipes have to be ripped out for testing and sanitizing. Recently, the staff at the National Institutes of Health Clinical Center in Bethesda, Maryland, experimented with reducing the amount of bacteria that can grow in a water system by “literally taking out plumbing and putting it in a different shape.”

One of the most extreme responses to an outbreak occurred at that same hospital, during a 2011 outbreak of an antibiotic-resistant Klebsiella pneumoniae carbapenemase, or KPC, a bacterium that can, like C. auris, cause infections in blood streams or wounds, leading to fevers, chills, a bloody cough, and eventually organ failure. Patients began testing positive for serious infections at a rate of around one per week, and standard cleaning failed to stop the spread. The hospital staff tore apart the plumbing in some rooms to remove sink drains where they found the bacteria lurking. They also used a robot to spray hydrogen peroxide in those emptied-out rooms after patients were moved to a separate ICU. (According to the Centers for Disease Control and Prevention, this technique has not been tested and proven effective and is therefore only recommended as an extra precaution after scrubbing everything else by hand.) These cleaning and isolation methods eventually worked, but of the 18 patients infected by KPC that year, six died from it.

The NIH case showed how techniques more advanced than bleach and isolation can come in handy to tackle outbreaks. A team of NIH researchers used genome sequencing to quickly decipher and trace the genetic code of the bacteria from one patient’s infection to another so that they were able to figure out how it had spread. According to a 2013 study from the case, the technology allowed the staff to determine that all the patients had been infected from one another, not independently, and they were able to pinpoint their areas of weakness. Advanced investigative approaches like this genetic sequencing have allowed hospitals to better track and confront the new and aggressive drug-resistant strains alarming the medical community.

The anxiety some medical professionals have about C. auris is valid: It is not acting in a way experts may have expected based on other forms of Candida, and that uncertainty translates into a need for caution. As experts have become more familiar with C. auris, they feel more confident about how to eradicate it from an environment and likely won’t need to take such extreme measures as ripping out parts of the ceiling and walls—a simple bleach cleaning would likely do the trick.

The real danger is in human fallibility: If someone fails to designate tasks clearly, a piece of medical equipment may fail to get the thorough disinfecting and sanitizing it needs in a crisis. The environmental services staff—the (sometimes underpaid) people in charge of scrubbing a patient’s room—often aren’t allowed to touch the medical equipment, and that discrepancy can allow germs to sneak through. Some medical equipment, such as X-ray machines, cannot be reserved for just one patient, and hospitals may struggle to eliminate bacteria from such bulky and complex machines. Manufacturers of hospital equipment can accidentally introduce contaminants to their products. And doctors and nurses, who often work long shifts, are susceptible to the kinds of careless mistakes we all make.

But still, patients shouldn’t worry too much about how their hospital is preparing for these new infections. As Susan Matthews wrote in Slate, your risk of being harmed, even if immunosuppressed, is extremely low.

The Explainer thanks Dr. Lisa Maragakis at the Johns Hopkins Health System and the Johns Hopkins University School of Medicine and Dr. Snigdha Vallabhaneni at the Centers for Disease Control and Prevention.