Ohmagari, N., Kurai, H., Yamagishi, Y., & Mikamo, H. (2014). Are strict isolation policies based on susceptibility testing actually effective in the prevention of the nosocomial spread of multi–drug-resistant gram-negative rods? American Journal of Infection Control, 42, 739–743.

There is an emerging problem of growing multi-drug resistant gram-negative rods (MDR-GNRs), and rapid and sensitive detection is difficult. There is no consensus regarding the list of drug-resistant bacteria to target for infection control and infection control policies for multi-drug resistant gram-negative organisms (DR-GNRs) often lack strong evidence to identify the minimum interventions needed to reduce their transmission. The authors were trying to determine if horizontal transmission can be prevented by detecting and appropriately controlling targeted drug-resistant bacilli before they acquire resistance.

In January 2005, a prevention policy against MDR-GNR infection was implemented. After isolating strains that met the defined criteria, contact precautions were implemented. Active interventions, including approval for specific antibiotics prior to use and regulating the prescription of certain antimicrobials, were not applied. The preintervention period (January 1, 2003 to December 31, 2004) was compared to intervention period (January 1, 2005 to December 31, 2010).

• N = 1,287,296 total inpatient days
• OTHER KEY SAMPLE CHARACTERISTICS: No exclusion criteria; active sampling from asymptomatic patients was not conducted; data included dates of detection, types of culture samples, inpatient or outpatient status, names of the detected strains, and results of susceptibility testing; inpatient days of care were defined as the sum of each daily inpatient census for the month

• SITE: Single site    
• SETTING TYPE: Multiple settings    
• LOCATION: Shizuoka Cancer Center, Nagakute, Aichi, Japan

• PHASE OF CARE: Multiple phases of care

Retrospective study (pre- and postintervention) based on the examination of a bacterial testing database

MDR-GNRs were defined as gram-negative bacilli that were insensitive to at least three of the specified classes of antimicrobials, metallo-beta-lactamase-producing bacilli, and extended spectrum beta-lactamase (ESBL)-producing bacilli. Strains of MDR-GNRs were isolated at least 48 hours after admission, and only newly detected stains were included and excluded cases in which the same strain was later detected in the same patients. Each species was included if multiple strains were isolated from the same patients.

The overall incidence density rate of all multi-drug resistant nonfermenting gram-negative bacilli over the eight-year study period (2003–2010) was 0.31 per 10,000 patient days. Rates did not increase significantly between the preintervention period (0.15 per 10,000 days) and the intervention period (0.35 per 10,000 days). The overall incidence rate of MDR enterobacteriaceae infections was 0.49 per 10,000 days. However, the preintervention period was 0.19 per 10,000 days, and the intervention was 0.56 per 10,000 days, representing a statistically significant decrease.

The study increased the detection of enterobacteriaceae bacteria with an increase in ESBL-producing organisms, but no significant change in detection rate of MDR non-glucose-fermenting bacilli was found. Contact precautions were implemented to limit the emergence of MDR-gram negative bacilli, but the efficacy of these policies was deemed uncertain.

• Retrospective study
• No active surveillance of asymptomatic patients
• Incidence measurements based solely on clinical cultures and may be insufficiently sensitive because asymptomatic patients may have been missed

MDR-GNRs are an emerging worldwide problem. Nurses have a significant responsibility to ensure proper precautions are taken as quickly as possible when these organisms are detected. Nurses should ensure that the patient is properly educated, but more importantly, should implement contact precautions and ensure that other healthcare providers are following these precautions.