Inconsistency seen as barrier to stopping resistant bacteria

Klebsiella pneumonia on agar plate
Klebsiella pneumonia on agar plate

Klebsiella pneumoniae, the most common drug-resistant Enterobacteriaceae, growing on an agar plate., CDC

Hospitals around the country vary considerably in how they define and address an important class of antimicrobial-resistant bacteria, and this inconsistency may be contributing to the rise of resistant strains, according to a new report in Infection Control and Hospital Epidemiology (ICHE).

In a related development, survey results released by the Association of State and Territorial Health Officials (ASTHO) indicate that about 70% of state health departments make an effort to promote antimicrobial stewardship, but only a few states have formal policies on that topic.

Findings from SHEA research network

The ICHE study was a survey of hospitals' approaches to multidrug-resistant gram-negative bacteria (MDR GNB), which include such common healthcare-associated pathogens as Acinetobacter, Pseudomonas, and the Enterobacteriaceae family, which includes Klebsiella pneumonia, among other species.

The survey was directed to 170 hospitals in the Society for Healthcare Epidemiology of America (SHEA) Research Network in an effort to assess how they define and deal with MDR GNB.

Sixty-six hospitals (39%) from 26 states and 15 other countries responded to the survey, according to the report. More than 80% of those reported having experience with each of the resistant strains mentioned. More than 78% said they had encountered GNB resistant to all antibiotics except colistin, an older drug that's known for kidney toxicity.

The hospitals reported many different specific definitions of MDR with respect to the different pathogens: 14 for Acinetobacter, 18 for Pseudomonas, and 22 for Enterobacteriaceae species.

The most common definition for multidrug resistance was resistance to three or more classes of antimicrobials, but other definitions included resistance to one or more specific antibiotics or antibiotic classes or susceptibility to two or fewer antibiotics (other than polymyxin or tigecycline).

The varied definitions influenced decisions on isolating patients. For example, 48% of hospitals used isolation for Enterobacteriaceae species only if they were resistant to more than three antimicrobial classes, while 15% set the isolation bar lower for those species.

Isolation practices also varied considerably by pathogen, the researchers found. For example, more than 90% of hospitals isolated patients infected with carbapenem-resistant Enterobacteriaceae (CRE), while 74% isolated those with extended-spectrum beta-lactamase (ESBL)–producing bacteria.

The duration of isolation—if used—also varied, ranging from the period of active illness to indefinite.

The authors comment that an international panel of experts published proposed definitions of MDR, extensive drug resistance, and "pandrug" resistance in 2012. Despite this, "We found that approximately one third of respondents were not using the proposed definition of MDR for isolation purposes," they write.

"Differences in definitions and practices for multidrug-resistant bacteria confuse healthcare workers and hinder communication when patients are transferred between hospitals," Marci Drees, MD, MS, lead author of the study, commented in a SHEA press release.

"The danger these inconsistencies represent affects not only individual hospitals, but the broader community because patients are frequently transferred between healthcare centers, including long-term care facilities, furthering their spread," she added.

Most states track resistance

The aim of the ASTHO survey was to assess what measures health departments are using to promote antimicrobial stewardship and what incentives and tools the agencies need. The effort targeted healthcare-associated infections (HAI) coordinators in the 50 states, Washington, D.C., and Puerto Rico; 36 of the 52 departments (69%) responded, according to a summary posted by ASTHO.

The survey was conducted in July 2013, but the results have not been released publicly until now, ASTHO spokesman Scott Briscoe told CIDRAP News.

The responses revealed that 56% (19 of 34) of the agencies collect surveillance data on antimicrobial resistance, though only 12% (4 of 34) receive funds for the work.

Twenty-five states, or 69%, reported that they engaged in antimicrobial stewardship activities, such as education and training, communications, surveys, collaborations, or demonstration projects. Most of the efforts targeted healthcare workers in hospitals and long-term care facilities.

Just five states reported having developed or implemented a policy on antimicrobial stewardship, according to the report. The states were not named in the ASTHO report.

Examples of the policies included a law requiring hospitals to evaluate judicious use of antibiotics, regulations that expand the reporting of resistant organisms and antibiotic-susceptibility rest results, and working with long-term care facilities on Clostridium difficile and the appropriate use of antibiotics.

Another six states, also not named, reported they had considered developing stewardship policies but had not yet done so.

The respondents also listed a number of measures that they thought would motivate antimicrobial stewardship activities, such as training, certification of individuals or facilities, state or national awards for facilities, and time for infection preventionists to work on stewardship.

See also:

Mar 6 ICHE study

Mar 7 SHEA press release on ICHE study

ASTHO issue brief on survey of state efforts

This week's top reads

Our underwriters