Strategies to Prevent MRSA Transmission and Infection in Acute-Care Hospitals

Implement a MRSA monitoring program. (Quality of evidence: LOW)

1. The MRSA monitoring program should do the following:

   1. Identify any patient with a current or prior history of MRSA to ensure application of infection prevention strategies for these patients according to hospital policy (eg, contact precautions).

   2. Provide a mechanism for tracking hospital-onset cases of MRSA for purposes of assessing transmission and infection and the need for response.

Conduct a MRSA risk assessment. (Quality of evidence: LOW)

1. The risk assessment should be attentive to 2 important factors: the opportunity for MRSA transmission and estimates of the facility-specific MRSA burden and rates of transmission and infection.

   1. The opportunity for transmission is affected by the proportion of patients who are MRSA carriers (colonization prevalence) who serve as a reservoir for transmission. Estimates of facility-specific MRSA transmission and infection rates reflect the ability of the facility’s current activities to contain MRSA, regardless of the burden of MRSA that is imported into the facility.

   2. Both colonization prevalence from sites performing active surveillance and rates of transmission and infection (eg, MRSA bloodstream infections, all MRSA-positive cultures) can be measured at either the total hospital level or for specific hospital units.

2. Findings from the risk assessment should be incorporated into the overall infection control program risk assessment and used to develop or refine mitigation strategies, surveillance, and goals based on the program’s prioritized risks.

3. Data used for initial and ongoing risk assessment can provide a baseline and can be used to monitor trends to inform the need for additional interventions. Metrics that might be used in the MRSA risk assessment are discussed in greater detail in Section 5 of this document.

Promote compliance with CDC or World Health Organization (WHO) hand hygiene recommendations. (Quality of evidence: MODERATE)

1. Hand hygiene is a fundamental strategy for the prevention of pathogen transmission in healthcare facilities.

2. A common mode of transmission of MRSA to patients is by contact with contaminated hands of HCP, and some investigators have attributed reduced rates of MRSA among hospital inpatients in part to efforts made to improve hand hygiene practices of HCP.

3. Promote patient hand hygiene.

Use contact precautions for MRSA-colonized and MRSA-infected patients. (Quality of evidence: MODERATE). A facility that chooses or has already chosen to modify the use of contact precautions for some or all of these patients should conduct a MRSA-specific risk assessment to evaluate the facility for transmission risks and to assess the effectiveness of other MRSA risk mitigation strategies (eg, hand hygiene, cleaning and disinfection of the environment, single occupancy patient rooms) and should establish a process for ongoing monitoring, oversight, and risk assessment.

1. Evidence for the use of contact precautions for MRSA-colonized and MRSA-infected patients

   1. Studies have demonstrated that HCP interacting with MRSA-colonized or MRSA-infected patients often become contaminated with the organism.

   2. Similarly, studies in acute-care hospitals have demonstrated that surfaces and objects in the patient’s environment frequently and quickly become contaminated. Placing patients with MRSA colonization or infection under contact precautions may help reduce patient-to-patient spread of MRSA within the hospital.

   3. Several recent nonrandomized studies and reports support the use of contact precautions for MRSA-colonized and MRSA-infected patients. From 2005 to 2016, the incidence of hospital-onset MRSA bloodstream infections in the United States declined 74%.The reasons for this decline probably are multifactorial, but interventions to reduce MRSA transmission likely played a role. In 2007, the US Department of Veterans’ Affairs (VA) implemented a MRSA prevention bundle at VA acute-care hospitals nationwide. Introduction of this bundle, which included universal nasal surveillance for MRSA, contact precautions for MRSA carriers, hand hygiene, and increased institutional awareness of infection control, was associated with significant reductions in healthcare-associated MRSA infections and MRSA transmission in ICU and non-ICU settings. By 2017, hospital-onset MRSA infections at VA hospitals had declined 66% compared to baseline, while hospital-onset MSSA infections declined by only 19%. Decreases in MRSA infections at VA hospitals during this time were significantly higher among patients with negative MRSA admission screening tests compared to those with positive MRSA admission screening tests, suggesting that interventions to decrease transmission within hospitals played a large role in reducing MRSA infections. A mathematical modeling study published in 2021 of the VA MRSA prevention intervention estimated that contact precautions alone reduced MRSA transmission by 47%. A large cluster-randomized trial conducted in ICUs outside the VA system demonstrated significant reductions in MRSA transmission with the implementation of universal glove and gown use.In this trial, mathematical models estimated that universal glove and gown use was estimated to have reduced transmission by 44%

   4. Based on a 2020 review of the current evidence, the CDC continues to recommend the use of contact precautions for MRSA colonized or infected patients

   5. During the COVID-19 pandemic, hospital-onset MRSA bloodstream infections increased nationally; however, whether declining use of contact precautions for MRSA-colonized or MRSA-infected patients played a significant role in this increase remains unknown

   6. Studies have suggested that patients may be persistent MRSA carriers for prolonged periods (median duration in one study, 8.5 months).Use of contact precautions for patients with a history of MRSA is recommended. ⁶⁷ However, the appropriate duration of contact precautions necessary for patients with MRSA remains an unresolved issue. Further considerations for discontinuing contact precautions for patients with MRSA can be found in the SHEA Expert Guidance by Banach et al.

2. Numerous studies have attempted to address whether contact precautions lead to an increase in adverse events.Some observational studies have shown an increase in adverse events including increased depression, anxiety, falls, electrolyte disorders, and decreased patient satisfaction.However, most of these studies did not control for comorbidity of patients and severity of illness of patients; thus, they suffer from confounding by indication. The only randomized trial to assess whether contact precautions lead to more adverse events showed a significantly lower frequency of HCP visits per hour (4.28 vs 5.24; P = .02) in ICUs using gowns and gloves for contact with all patients compared with control ICUs using gowns and gloves only for patients known to be colonized or infected with antimicrobial-resistant organisms and as otherwise required for CDC-defined contact precautions. The incidence of adverse events, though, was not significantly different between the 2 groups. In fact, rates of preventable, nonpreventable, severe, and nonsevere ICU adverse events were all nonsignificantly lower in the intervention group. Rates of hand hygiene on room exit were significantly higher in the universal glove-and-gown group. With randomized trials being a higher level of evidence than observational studies, current evidence does not indicate that contact precautions lead to an increase in adverse events.

3. Evidence on the impact of discontinuation of contact precautions for MRSA-colonized and MRSA-infected patients:

   1. In recent years, several studies have sought to characterize the impact of discontinuing contact precautions for MRSA-colonized and MRSA-infected patients. Many of these studies have demonstrated that discontinuing contact precautions did not lead to an increase in HAIs. However, most were single-center, quasi-experimental studies that were underpowered and did not assess the effect of discontinuing contact precautions on MRSA acquisition or postdischarge MRSA infections. Thus, they were not designed to adequately detect the full impact of discontinuing contact precautions. Only 2 discontinuation studies used MRSA acquisition as an outcome. We acknowledge that, due to the large cost of performing cluster-randomized trials, no trial at present has evaluated contact precautions versus no contact precautions for MRSA. The closest study was the BUGG trial, which demonstrated significant reductions in MRSA acquisitions in ICUs that adopted universal gown-and-glove use.

4. Considerations for facilities that choose to modify the use of contact precautions for some or all MRSA-colonized or MRSA-infected patients:

   1. Hospitals should conduct a MRSA risk assessment based on internal infection rates, local epidemiology, hospital infrastructure (eg, proportion of non-private patient room) that may contribute to patient-to-patient transmission of MRSA if contact precautions are not used, and other factors. Please refer to Essential Practices recommendations 2. and 4.f.2 regarding use of a MRSA risk assessment and Section 5 for a list of metrics that can be used in the risk assessment.

      1. When making the decision to discontinue contact precautions for all or a subset of patients with MRSA, a facility should establish a policy and process that supports and communicates this change.

      2. At a minimum, a facility should provide guidance related to inclusion and exclusion criteria related to the process change; laboratory testing and surveillance strategies; implementation and communication; ongoing risk assessment; and oversight (eg, infection prevention committee) as appropriate.

   2. Hospitals with ongoing MRSA outbreaks or with high or increasing rates of MRSA infection or hospital-onset MRSA-positive cultures* should not discontinue contact precautions for MRSA-colonized or MRSA-infected patients. *If active surveillance testing is used hospital-wide or in select situations, data regarding rates of acquisition of MRSA colonization may also be used in decisions to modify the use of contact precautions.

   3. Based on the risk assessment, hospitals may choose to prioritize certain high-risk populations for which to continue contact precautions. High-risk populations identified may include the following:

      1. ICU patients

      2. NICU patients

      3. Burn-unit patients

      4. Dialysis patients

      5. Transplant and other specialty units with immunocompromised patients

      6. Patients with indwelling devices such as central venous catheters

      7. Patients with active infections, particularly those with uncontained wounds or secretions

      8. Residents of long-term acute-care hospitals

      9. Residents of long-term care facilities

   4. Hospitals that choose to modify the use of contact precautions for some or all MRSA-colonized or MRSA-infected patients should, at a minimum, have strong horizontal prevention practices in place and demonstrate high adherence to these mitigation strategies. These practices may include audits, rounding, and teams to address the following:

      1. Hand hygiene

      2. Standard precautions

      3. Environmental cleaning and disinfection

      4. PPE adherence and discontinuation of extended use and reuse of gowns and gloves

      5. CLABSI prevention

      6. SSI prevention

5. Hospitals that choose to modify the use of contact precautions for some or all MRSA-colonized or MRSA-infected patients should consider implementing a MRSA decolonization program for certain high-risk groups or high-risk settings (eg, ICUs). (See decolonization recommendations in the Additional Approaches section.)

6. Hospitals that choose to modify the use of contact precautions for some or all MRSA-colonized or MRSA-infected patients should monitor key metrics (see 4.f.2) and reconsider the use of contact precautions if an outbreak occurs or if MRSA rates increase.

   1. Establish appropriate metrics that capture changes in rates of MRSA infection or transmission. Incorporate these metrics in the ongoing risk assessment and make adjustments to the use of contact precautions or other infection prevention strategies when appropriate. Note: These metrics may be underpowered and limited in their ability able to identify all downstream effects of changes to the use of contact precautions.

   2. Possible key metrics to monitor include the following:

      1. MRSA clinical culture positivity rates

      2. Hand hygiene compliance

      3. Compliance with hospital designated decolonization protocols including chlorhexidine bathing and intranasal treatment (eg, mupirocin)

      4. Hospital-onset MRSA infections, including device-associated infections, procedure-associated infections such as SSIs, bloodstream infections, and other infection types such as pneumonia or skin and soft tissue as appropriate based on historical data

      5. MRSA acquisition rates if active surveillance testing is in place (see active surveillance testing recommendations in Section 5, Additional Approaches for Preventing MRSA Infection)

      6. Rates of admission with new MRSA infection or colonization (among persons without prior history of MRSA colonization or infection) within 30–90 days of prior hospital discharge

         1. This metric is intended to identify patients who may have acquired MRSA during a recent hospital admission. Studies have demonstrated that prior hospitalization is a common risk factor for non–hemodialysis-related healthcare-associated community-onset MRSA infection, with the majority occurring within 12 weeks of a prior hospital admission.

Ensure cleaning and disinfection of equipment and the environment. (Quality of evidence: MODERATE)

1. MRSA contaminates the patient environment (eg, overbed tables, bedrails, furniture, sinks, floors) and patient care equipment (eg, stethoscopes, blood pressure cuffs, etc). MRSA contamination on surfaces around the patient zone varies in bioburden concentration.

2. Exposure to this contaminated environment has been associated with acquisition of MRSA.Improvements in environmental cleaning have been associated with reductions in MRSA acquisition among patients admitted to rooms in which the previous occupant was colonized or infected with MRSA.

3. Cleaning and disinfection are horizontal infection practices that can prevent transmission of multiple pathogens.

4. Objective monitoring of the thoroughness of cleaning and disinfection using direct observation, fluorescent marking systems, and/or ATP detection systems with feedback of monitoring results to personnel responsible for cleaning has been associated with improvements in environmental cleaning and disinfection in healthcare settings.

Implement a laboratory-based alert system that notifies HCP of new MRSA-colonized or MRSA-infected patients in a timely manner. (Quality of evidence: LOW)

1. Timely notification of new MRSA-positive test results to clinical caregivers and infection preventionists facilitates rapid implementation of contact precautions and other interventions (eg, treatment of infection) as appropriate according to facility policy, assessment of risk, and timely surveillance for HAIs.

Implement an alert system that identifies readmitted or transferred MRSA-colonized or MRSA-infected patients. (Quality of evidence: LOW)

1. An alert system allows information regarding the MRSA status of the patient to be available at the first point of contact (eg, emergency department arrival, presentation to admitting department), prior to bed assignment, to promptly initiate appropriate control measures and minimize opportunities for transmission.

2. Alerts facilitate early prevention interventions within the continuity of care, such as internal transfers between inpatient units or interfacility transfers managed via regional patient transfer centers.

3. Communication at the time of procedure scheduling and verbal hand-off safety practices (eg, SBAR—situation, background, assessment, recommendation) allows for planning and continuity of prevention activities at the time of patient transport and in the receiving service department (ie, imaging, cardiac catheterization, etc).

Provide MRSA data and outcome measures to key stakeholders, including senior leadership, physicians, nursing staff, and others. (Quality of evidence: LOW)

1. Provision of MRSA data and other information related to the activities of the MRSA prevention program to key stakeholders on a regular and frequent basis may optimize focus on MRSA prevention efforts, substantiate requests for resources, and increase engagement in the MRSA prevention program. (See Section 5 for suggested metrics for assessment of the MRSA prevention program.)

Educate healthcare personnel (HCP) about MRSA. (Quality of evidence: LOW)

1. Several key components of an effective MRSA prevention program involve modification of HCP behavior (eg, hand hygiene, contact precautions, environmental cleaning, and disinfection).

2. HCP should be educated about their role in MRSA prevention and other MRSA-related topics as appropriate.

Educate patients and families about MRSA. (Quality of evidence: LOW)

1. Patients and their families should be educated regarding the importance of hand hygiene and respiratory etiquette to reduce the risk of spread of MRSA and other pathogens during the hospital stay.

2. Patients who are colonized or infected with MRSA and their families should be educated about MRSA and what they can do to reduce the risk of infection and transmission.

Implement an antimicrobial stewardship program. (Quality of evidence: LOW)

1. Receipt of antibiotics without MRSA activity has been associated with significant increases in the intranasal burden of MRSA. Thus, receipt of such antibiotics may increase the risk of infection in the colonized person and/or increase risk of transmission to others.

2. However, the association between antimicrobial stewardship interventions and rates of MRSA infection and colonization has varied among studies. Of 3 recent systematic reviews and/or meta-analyses, 2 found an association between implementation of antimicrobial stewardship interventions and a decreased incidence of MRSA infection and/or colonization.

3. The quality of evidence for antimicrobial stewardship as a component of a MRSA prevention program is low (eg, mostly single-center, nonrandomized, uncontrolled studies). However, a theoretical rationale and some evidence of benefit do exist, and no evidence of harm has been reported. In addition, benefits of antimicrobial stewardship have been established for other important outcomes (eg, C. difficile prevention).

4. Please refer to the “Compendium of Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2022 Update” and current guidelines for surgical antibiotic prophylaxis for recommendations regarding surgical antibiotic prophylaxis among patients known to be colonized with MRSA.