Working together to stop superbugs

The battle against antimicrobial resistance requires a broad line of attack, prompting the CDC to fund projects to expand regional efforts against multidrug-resistant organisms.

Good hand hygiene? Check. Judicious antimicrobial prescribing? Check. Following CDC recommendations? Of course.

Physicians are familiar with typical antimicrobial stewardship and infection prevention strategies. But the battle against antimicrobial resistance requires an even broader line of attack, since superbugs spread as infected or colonized patients transfer between health care facilities, said John A. Jernigan, MD, MS, director of the CDC's Office of HAI Prevention Research and Evaluation.

“As patients move, the bugs move with them,” he said. “We think that our best chance of success in controlling superbugs in the future is by taking a regional approach.”

There are a variety of battlefronts involved in the war against antimicrobial resistance Image by urfinguss
There are a variety of battlefronts involved in the war against antimicrobial resistance. Image by urfinguss

To do this, the CDC has funded projects to expand regional efforts against multidrug-resistant organisms (MDROs). Two of them, SHIELD Orange County in California and Chicago PROTECT in Illinois, provide a glimpse into what teamwork among hospitals, nursing homes, and other facilities can accomplish.

“No health care facility is an island. What happens in their facility impacts what happens in other facilities with whom they share patients, and vice versa,” said Dr. Jernigan, also a clinical associate professor of medicine in the division of infectious diseases at Emory University School of Medicine in Atlanta. “When those facilities are working together to address this problem, that's when we're going to make the best progress.”

Help from a special soap

In Orange County, 35 health care facilities joined the SHIELD (Shared Healthcare Intervention to Eliminate Life-threatening Dissemination of MDROs) project. Invited facilities shared many patients among them, so they had a reason to act collaboratively, said Susan S. Huang, MD, MPH, FACP, the project's principal investigator.

The two-part intervention included using chlorhexidine as a body soap and a nasal povidone-iodine swab to decolonize hospitalized patients who were on contact precautions, as well as every resident in participating nursing homes and long-term acute care hospitals, she said. At baseline, the prevalence of MDROs was 65% in nursing homes and 80% in long-term acute care hospitals, according to results published in February 2019 by Clinical Infectious Diseases.

Unlike alcohol hand rub or regular soap and water, chlorhexidine binds to the proteins of the skin and continues to kill germs for about 24 hours, Dr. Huang noted. “If you're able to clean people or bathe them on a regular basis, you may actually be protecting them for much longer than the actual bath itself,” she said. The nasal iodine swab was particularly used to address the fact that the most common MDRO, methicillin-resistant Staphylococcus aureus (MRSA), lives primarily in the nose.

From July 2017 to July 2019, preliminary findings showed that SHIELD led to impressive reductions in MDROs like MRSA and vancomycin-resistant enterococci (VRE), said Dr. Huang, also a professor of medicine in the division of infectious diseases at the University of California, Irvine, School of Medicine. “We were able to drop MDROs by 30% in the hospital setting, which is very exciting,” she said. “In the nursing homes, we were able to drop them by about half.”

One of the challenges of the chlorhexidine intervention was the antiseptic's name. Although it was already commonplace in the hospitals due to its use in ICUs, the nursing home staff took more time to become comfortable, Dr. Huang said. “It's just another soap,” she said. “It's over the counter, it's safe, but the name of it sounds a bit daunting.”

In the hospitals, the hardest challenge was developing a different process for patients who were positive for MDROs, she said. However, California is one of several states where legislation requires hospitals to perform active-surveillance cultures for MRSA in certain high-risk groups. So the intervention simply targeted those who were already on contact precautions. “Generally, the visible sign on the door can help nurses remember to apply chlorhexidine and use nasal decolonization in this room,” Dr. Huang said. Hospitals that could develop electronic prompts, flags, and orders in the electronic health record were far more adherent to the intervention than those that couldn't, she noted.

Some might assume that nursing assistants instinctively know how to bathe patients, but training was necessary to make sure that decolonization was performed correctly, Dr. Huang said. “It's very natural for a nursing assistant to avoid the areas where the skin is broken and to only clean the intact skin,” she said. “It's well known that if you don't clean those areas, you will derive none of the benefit.”

Facilities that did not take part in SHIELD appear to have benefited from their neighbors' efforts. Overall, there has been a 25% reduction in MDROs throughout Orange County since the intervention launched, Dr. Huang reported. For Dr. Jernigan at the CDC, this preliminary result is impressive. “There's collateral benefit, if you will, from other facilities that share patients with the intervening facilities,” he said.

Even though the CDC-funded intervention has come to an end, there are plans to continue these efforts in the future. While all of the hospitals aim to maintain the program, they were concerned that its benefits would be diminished if the nursing homes, which have fewer resources, were unable to continue, Dr. Huang noted.

The County Organized Health System for Orange County, CalOptima, which is the largest Medicaid plan in California, quelled these concerns in June 2019 by investing in a quality initiative for all 67 nursing homes in the county that will provide financial support and oversight for the soap and nasal decolonization that the intervention requires, she said.

Through its own data, CalOptima was seeing reductions in hospital admissions for infection from participating skilled nursing facilities, Dr. Jernigan said. “They saw enough value in it that they would invest in the intervention themselves,” he said. “We are hopeful that the gains that we've seen in this relatively short term are only the beginning. If we are able to sustain the intervention across the region, we think it will continue to accrue benefits.”

Keeping tabs on colonized patients

Another way hospitals and other care facilities are working together is by tracking patients with MDROs. In Illinois, health care facilities across the state participate in the XDRO (extensively drug-resistant organism) registry, said Michael Lin, MD, MPH, an associate professor in the division of infectious diseases and hospital epidemiologist at Rush University Medical Center in Chicago.

The registry, which first launched in November 2013, was developed by the Illinois Department of Public Health, the Medical Research Analytics and Informatics Alliance, and Cook County Health. The Chicago Prevention Epicenter at Rush University Medical Center and Cook County Health collaborated on the conception and design of the registry, noted William E. Trick, MD, FACP, director of the Collaborative Research Unit at Cook County Health.

The XDRO registry functions as a multifacility alert system for patients with carbapenem-resistant Enterobacteriaceae (CRE) and is currently promoted as part of a larger regional CRE control project called Chicago PROTECT (Providing Regional Organizations with TEchniques to ConTrol MDROs).

Similar to SHIELD, Chicago PROTECT promotes the use of chlorhexidine bathing in selected postacute facilities at high risk of CRE. In addition, the expanded adoption of the XDRO registry allows an increasing number of hospitals and nursing homes to employ a “detect and protect” strategy to identify patients who are carrying CRE at the time of admission and apply timely infection control precautions. “The hope is that if we intervene at high-risk facilities, the entire region will see a decline in antibiotic resistance,” said Dr. Lin, the project's principal investigator.

Any time a patient is identified as carrying CRE, an infection preventionist enters the patient into the registry. An increasing number of hospitals access the registry in real time on an automatic basis, Dr. Lin said. For example, at Rush, when a patient is admitted and matches the registry, the hospital's infection preventionists get an email and a page to notify them that contact precautions are necessary, he explained.

“If you ask the infection preventionists in general, my impression is that they really like having that situational awareness,” said Dr. Lin. All Illinois nursing homes also have access to the registry, although they query the registry manually at this time.

While the somewhat ominously named XDRO registry began with a focus on CRE, it has built-in flexibility so that more organisms can be added as needed, said Dr. Lin. “There is a recognition that we don't know what's going to be the next big thing,” he said, adding that the multidrug-resistant yeast Candida auris was added to the registry by the Illinois Department of Public Health once it was detected in the state.

Chicago PROTECT wrapped up in September 2019, and the CDC is working with the project team to evaluate the results, Dr. Jernigan said. “In addition, we're making investments in state and local health departments to address the issue of multidrug resistance and superbug spread,” he said.

Meanwhile, the registry, which will remain in effect in Illinois, has seen positive results in computer modeling research. One recent study showed that implementing a registry that tracks patients carrying CRE may help reduce regional spread, even with modest participation among inpatient facilities.

Based on an agent-based simulation model of the Chicago Metropolitan Area, in a scenario where about 400 inpatient health care facilities in Illinois participated in the registry, the number of new CRE carriers would decrease by 11.7% and region-wide CRE prevalence would decrease by 7.6% over a three-year period, according to results published in May 2019 by Clinical Infectious Diseases. Even with just 25% participation among the largest facilities, the study found a projected 9.1% relative reduction in incident carriers and a 2.8% relative reduction in prevalence.

The finding that even a registry with low participation provides value is important, according to study author Bruce Y. Lee, MD, MBA, who leads the team that developed the model. “That attests to the fact that this patient-sharing network is extremely extensive and complex,” he said.

Registries like this have been widely considered in the U.S. for more than a decade, but there are several barriers to their implementation, such as a reluctance to share information across facilities and differences in record-keeping capabilities, noted Dr. Lee, an associate professor of international health at Johns Hopkins Bloomberg School of Public Health in Baltimore.

Despite the challenges, growing concerns about the spread of superbugs mean that MDRO registries will likely be increasingly considered in the future, he said. “You can't tackle something if you don't know where it is.”