The longstanding confusion about when it is safe to take patients with transmissible pathogens out of contact precautions has led to the default position some infection preventionists have called “isolation for life.”

That is, if you are unsure whether a colonized or asymptomatic patient can spread an organism — particularly an emerging one — it has become common to err on the side of contact isolation.

On the other hand, contact precautions are labor- and resource-intensive and prolonged isolation can have adverse effects on patients.

While there is a dearth of data to make completely informed decisions on aspects of this issue, the Society for Healthcare Epidemiology of America (SHEA) has issued a guidance document¹ that hospitals can use as a framework for making policy.

“There is a lot of interest in areas where guidance is needed, but there is just very limited data,” says lead author David Banach, MD, MPH, MS, epidemiologist at the University of Connecticut Health Center in Farmington. “The goal of this was to provide guidance to hospitals based on the data that’s been published with acknowledged limitations. We tried to develop a process in which hospitals can apply practical recommendations for the duration of contact precautions.”

The document is specific and intentional in using the word “guidance” instead of “guidelines,” and avoiding an overly prescriptive approach.

“The general message is that hospitals should look at their own epidemiology and their patient populations and develop some process that they can use to make decisions, taking into account some of the principles and guidance in the document,” he says. “It is certainly not a one-size-fits-all process for hospitals.”

In addition, the question of whether isolation precautions should be used for a given situation — an ongoing debate in its own right — is not addressed.

“That is still an area under study,” he says. “We are trying to provide some practical guidance based on the literature on duration of contact precautions. We tried to use the existing limited evidence base while thinking about the bigger picture on how contact precautions are used in healthcare settings.”

Based in part on a survey of SHEA members, the document addresses discontinuing contact isolation for precautions for MRSA, vancomycin-resistant enterococci (VRE), Clostridium difficile, and multidrug-resistant Enterobacteriaceae (MDR-E). The latter includes the emerging threats of carbapenem-resistant Enterobacteriaceae (CRE) and extended-spectrum beta-lactamase (ESBL)-producing organisms.

In that regard, the guidance recommends extending contact precautions at least six months after the last positive culture for CRE. In addition, SHEA recommended obtaining at least two consecutive negative rectal swab samples at least one week apart to consider an individual negative for ESBL-E or CRE colonization.

“A lot of that stemmed from the data that supports longer carriage with these organisms, as well as the practical aspects and the limited number of antibiotic options,” Banach says.

Clostridium difficile

With regard to C. diff, the SHEA guidance states the following:

• “We recommend that patients with C. diff infection (CDI) receive care with contact precautions (CP) for at least 48 hours after resolution of diarrhea;
• Hospitals should consider extending CP through the duration of hospitalization if elevated rates of CDI are present despite appropriate infection prevention and control measures;
• Insufficient evidence exists to make a formal recommendation as to whether patients with CDI should be placed on CP if they are readmitted to the hospital.”

In weighing the issue, consider that “patients that are [C. diff] carriers shed the organism in their stools for weeks after cessation of diarrhea,” SHEA advised.

“The shedding of C. difficile spores after resolution of diarrhea may contribute to the spread of this organism,” SHEA states. “Recent data suggest that isolation of asymptomatic carriers reduced the incidence of C. difficile in the hospital setting.”

Given these findings, some hospitals may want to extend precautions, SHEA recommends.

With C. diff at epidemic proportions nationally, we asked Banach, “Why not draw the line at discontinuing isolation at 72 hours after symptoms?”

“We did consider that,” he says. “I think that institutions should look at their C. diff rate and decide which option they think is more appropriate for their hospital. It is somewhat of a challenge weighing the practical aspects of prolonged isolation with contact precautions versus transmission risk. We say ‘at least’ 48 hours, and if hospitals have concerns they can certainly wait longer.”

Use of molecular testing to accurately confirm whether someone was colonized or infected will eventually play much more of a role in these decisions, but SHEA thought there was insufficient data to provide detailed guidance. The situation was similar in looking at the research on decolonizing patients with the various organisms.

“There was another area we talked about,” he said. “We felt like the data was not sufficient enough to make a firm recommendation. In a couple of the sections there is some [discussion] of the studies on decolonization and how they have been evaluated.” In any case, the document can serve as a useful framework for those that do not have discontinuation policies, which Banach was surprised to learn was not an insubstantial number of hospitals.

“That was really the goal,” he says. “At least hospitals can start to think about their own patient population and epidemiology and use some of the guidance in the document to come up with an institutional policy.”

REFERENCE

1. Banach DB, Bearman G, Barnden M, et al. Duration of Contact Precautions for Acute-Care Settings. Infect Control Hosp Epi 2018;1-18:doi:10.1017/ice.2017.245.