By Gary Evans, Medical Writer
Pathogens and patients move together across an interconnected healthcare continuum, meaning no matter how high a level of infection prevention is achieved in one hospital it is still at the mercy of a wide variety of transferring facilities, said Tom Frieden, MD, director of the CDC.
Delivering the keynote address recently in New Orleans at the IDWeek 2016, Frieden emphasized that healthcare facilities must communicate and collaborate across the diverse continuum if an emerging array of multidrug resistant and problematic pathogens are to be kept at bay.
“Healthcare facilities are not islands,” he said, showing a slide heavily criss-crossed with lines depicting the movement of patients between hospitals and other healthcare facilities. “Every line depicts at least 10 patient transfers within a single year. So, you get a sense of the complexity of patient movement within facilities and this is important because we will only be able to make substantial progress in reducing drug resistant infections and nosocomial infections if there is good work among facilities. Even if you are practicing at the best facility in the world, you are in many ways at the mercy of the nursing home down the block, the healthcare provider across the town, and the long-term acute care facility that sends patients to you. Patients move and the bacteria and infections move with them. By working together, coordinating within a community, facilities can make a [big] difference -- much more than any one facility can make on its own.”
Another presentation that drove this point home at IDWeek showed how Clostridium difficile infections (CDIs) are being spread by patients across facilities in Oregon and Washington. C. diff is being spread by colonized or infected patients moving between skilled nursing facilities, nursing homes and various types of hospitals. Again, the lines of connection virtually blackened the slide between the colored nodes that represented the various facilities.
“When we look at rates of CDI you think of it as a problem within a hospital,” said Rachel Slayton, PhD, MPH, an epidemiologist in the CDC division of Healthcare Quality Promotion. “But these data suggest that healthcare facilities are tightly connected to one another with the patients that they share. Over an interval of time colonization from a previous stay [may] effect patients risk of colonization or infection at a subsequent stay. I think this suggests when we look at interventions that we should look at how patients are moving more broadly rather than a siloed approach within individual facilities.”
In the study, Slayton and colleagues concluded that connectedness to other healthcare facilities was independently associated with facility-level CDI incidence. Hospitals that were most highly connected had significantly higher rates. Hospitals with high connectivity might provide a target group for coordinated public health interventions to reduce CDI regionally, they noted.1
“The hospitals that were most highly connected to other facilities through patient sharing had higher rates of incidence of facility-wide CDI even when you control for bed size, teaching status and CDI test type,” Slayton said. “So, it is not just your large academic medical centers. We think that systematically assessing facility connectedness can provide insight into prioritizing facilities for identifying novel strains and implementing enhanced prevention measures.”
In this highly-interconnected healthcare system, public health departments can serve as a neutral space for coordination among facilities, Frieden says. The CDC is finding that these types of collaborative networks can make a significant difference in infection rates.
“It’s not just what one hospital can do, it is about the coordination among facilities,” he says.
For example, an analysis done by the CDC projected the level of (Carbapenem-Resistant Enterobacteriaceae (CRE) that would result in five years if it entered 10 healthcare facilities that were sharing patients. If everything stays at the status quo – meaning the facilities don’t improve infection control or collaborate to control the CRE – the pathogen would increase by 12% and result in 2,000 infections in 5 years.
“If each facility does a really good job -- but they don’t coordinate among themselves -- you’ll do better than that, cutting infections to about a quarter to 8% -- 1500 infections,” Frieden said. “But if you have a coordinated approach where the facilities are working together, you can drive those numbers down considerably. We have seen progress in communities across the U.S. driving CRE down by 75% or more. This is because in many circumstances the increase in drug resistance is not merely a general evolutionary trend of the bacteria. It’s a clonal expansion because of an outbreak of individual organisms. And that is something that can be identified more quickly and stopped, but only if it is done across an entire community, including addressing the [patient] referral patterns.”
That raises the old issue of communicating thoroughly about patients coming and going between various types of facilities.
“We need information sharing,” he said. “When you send a patient with CRE to the long-term care facility they need to know in advance and vice versa.”
Turning Back the Clock
As represented by CRE, C. diff and other pathogens, antibiotic misuse and the resulting resistant bacteria are among the top threats to patient safety.
“Antibiotic resistance, as you know, risks turning back the clock,” he said. “[We are at risk of] going from a pre-antibiotic, to an antibiotic, to a post-antibiotic era. And it is not only that pneumonia and urinary tract infections could be fatal. It is also that modern medicine could be undermined.”
For example, 600,000 patients undergo chemotherapy for cancer every year.
“And we presume that we will just be able to treat their infections until their immune system reconstitutes, but that may not always be the case,” Freiden said. “We need to act now because we cannot know with certainty that we will have new and better drugs in the future.”
The accumulating evidence of this crisis finds that one out of ever six central line associated bloodstream infections is caused by bacteria resistant to antibiotics. Similar rates are occurring in surgical site infections and increases in C. diff are being driven by antibiotic overkill that wipes out the commensal bacteria that protect the gut flora.
“The metaphor of a ‘war’ against bacteria is really misleading,” Frieden said. “If you look at the microbiome, our 23,000 or so genes are up against 1 million or so bacteria that call each of our bodies home. Until a few months ago, around 80% of the bacteria in our intestines had never been cultured, though we knew they were there from sequencing. [But] we don’t have to go to the bottom of the ocean or to Mars to look for unusual bacteria. They are within us. And they may contain within them important messages on what maintains health and what can be used to control infections. There are many more friendly bacteria around than there are unfriendly ones, and we disrupt them at our peril. The dictum of ‘above all do no harm’ also relates to the microbiome. We are just beginning to scratch the surface of what we need to know to do that.”
Indeed, the microbiome of commensal bacteria may function in some sense as a “separate organ” in the human body.
“It may protect us,” he said. “It may have metabolic functions. It may help us with digestion. There are a lot of things that the healthy microbiome does. When we use antibiotics, we wipe out the good with the bad and we leave behind a system that doesn’t have the usual protectors. Because of the relative absence of our friendly bacteria the body becomes susceptible to infection and resistant bacteria can thrive in that disrupted microbial environment.”
One of the most compelling examples of the critical role of gut flora is the increasing use of fecal transplants to fend off recurrent CDI.
“The dramatic effectiveness of this type of intervention is a hint of the type of strategies that may become widespread in the future,” Frieden said.
All the while novel pathogens continue to emerge, with one of the most recent being a multidrug resistant strain of Candida auris that is emerging globally and has been reported in the United States.2
“There is a lot we don’t know about C. auris, but it proves that the old way of doing business to combat resistance isn’t enough,” Frieden told IDWeek attendees. “We don’t know why unrelated C. auris strains have recently emerged in various countries. They have caused invasive healthcare-associated infections with high mortality in debilitated patients. Some strains have been identified that have elevated MICs [minimum inhibitory concentrations] to the three major anti-fungal [drug] classes, which obviously severely limits treatment options.”
The CDC is uncertain whether the sudden emergence represents a new type of C. auris or one that has somehow adapted to “either longstanding practices or emerged through [more recent] changes in clinical practice,” he said. “It requires specialized identification methods so it could now – and could have in the past – been missed with our standard microbiology.”
Just as hospitals and other healthcare facilities must collaborate and recognize their interconnectedness, individual countries cannot hope their borders will protect them from pathogens that emerge in other parts of the world.
Citing a personal example, Frieden recalled once treating a patient from India with an extremely multidrug resistant (MDR) strain of tuberculosis. It took nearly two years of expensive interventions and surgeries to save him, but years later traveling to India Frieden realized that basic, inexpensive interventions at the local level could have stopped the TB infection at its source.
“We are all connected by trends around the world,” he said.
Thus, the efforts of the World Health Organization include surveillance for MDR-TB, which can arise through failure to treat patients or by exposing them to anti-TB drugs without completely eradicating the infection.
“No program, no well how well resourced, can treat MDR-TB faster than a bad program can create MDR-TB,” Frieden said.
Critical to the success of public health programs in the U.S. and internationally are three characteristics: technical rigor, operational excellence, and political will, he said. Though global response and communications have improved with a series of emerging infections in recent years, there is little margin for error when a potential pandemic is on the horizon.
“A blind spot anywhere is a vulnerability everywhere,” Frieden said.
To turn the tide on antimicrobial resistance improvement is needed in several fundamental areas, he said.
“First, we need to find [drug-resistance] faster and more completely in many different venues -- hospitals, nursing homes, the community, animals, and our food supply,” Frieden said. “We need to figure out where it is and find it when it first emerges.”
The need to prevent drug resistant bacteria much more thoroughly, of course, means the major national emphasis on antibiotic stewardship must continue and expand.
“That means much better antibiotic stewardship than we have today,” he said. “A third or half of all the antibiotics prescribed in this country are either unnecessary or of an overly-broad spectrum. We need system-wide infection control. Clearly, I think if we look back in 20 or 30 years, we will look at the hospitals today – despite a lot of great efforts – [and think] ‘how could they have been so cavalier about the risk of cross infections?’” Because 75,000 Americans a year dying of infections picked up in the hospital is not an acceptable situation.”
Infection preventionists can’t do it alone. New vaccines and diagnostic tests are needed as well as wider application of molecular epidemiology to breakdown outbreaks at the granular level.
“We criticize doctors for giving necessary antibiotics, but if you could with a simple, rapid test [determine drug resistance], we would see much less inappropriate prescribing,” he said. “Bacteria are very effective at evolving. As [late Nobel Laureate] Josh Lederberg used to say, ‘They outnumber us and we’d better outsmart them.’ They have evolved to survive using natural selection. For us to outsmart them we need to use rigorous collection and analysis of data to hone our practices so that we can stay ahead of the bacteria.”
- Slayton R, Baggs J, McCormick K, et al. Association Between Healthcare Facility Connectedness and the Incidence of Clostridium difficile Infections, Washington and Oregon. Oral abstract session. IDWeek Oct. 26-30, 2016. New Orleans, LA.
- Centers for Disease Control and Prevention. Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus — United States, May 2013–August 2016 MMWR Early Release / November 4, 2016: http://bit.ly/2fmiHvq