An integrated approach to methicillin-resistant Staphylococcus aureus control in a rural, regional-referral healthcare setting

Approaches to multidrug-resistant organism prevention and control in long-term care facilities for older people: a systematic review and meta-analysis

BACKGROUND

Despite clear evidence of benefits in acute-care hospitals, controversy over the effectiveness of IPC measures for MDROs is perceptible and evidence-based practice has not been established.

OBJECTIVE

To investigate the effects of IPC interventions on MDRO colonization and infections in LTCFs.

DATA SOURCES

Ovid MEDLINE, EMBASE, and CINAHL from inception to September 2020.

ELIGIBILITY CRITERIA

Original and peer-reviewed articles examining the post-intervention effects on MDRO colonization and infections in LTCFs.

INTERVENTIONS

(i) Horizontal interventions: administrative engagement, barrier precautions, education, environmental cleaning, hand hygiene, performance improvement, and source control; and (ii) vertical intervention: active surveillance plus decolonization.

STUDY APPRAISAL AND SYNTHESIS

We employed a random-effects meta-analysis to estimate the pooled risk ratios (pRRs) for methicillin-resistant Staphylococcus aureus (MRSA) colonization by intervention duration; and conducted subgroup analyses on different intervention components. Study quality was assessed using Cochrane risk of bias tools.

RESULTS

Of 3877 studies identified, 19 were eligible for inclusion (eight randomized controlled trials (RCTs)). Studies reported outcomes associated with MRSA (15 studies), vancomycin-resistant Enterococci (VRE) (four studies), Clostridium difficile (two studies), and Gram-negative bacteria (GNB) (two studies). Eleven studies were included in the meta-analysis. The pRRs were close to unity regardless of intervention duration (long: RR 0.81 [95% CI 0.60-1.10]; medium: RR 0.81 [95% CI 0.25-2.68]; short: RR 0.95 [95% CI 0.53-1.69]). Vertical interventions in studies with a small sample size showed significant reductions in MRSA colonization while horizontal interventions did not. All studies involving active administrative engagement reported reductions. The risk of bias was high in all but two studies.

CONCLUSIONS

Our meta-analysis did not show any beneficial effects from IPC interventions on MRSA reductions in LTCFs. Our findings highlight that the effectiveness of interventions in these facilities is likely conditional on resource availability-particularly decolonization and barrier precautions, due to their potential adverse events and uncertain effectiveness. Hence, administrative engagement is crucial for all effective IPC programmes. LTCFs should consider a pragmatic approach to reinforce standard precautions as routine practice and implement barrier precautions and decolonization to outbreak responses only.

Updates on Infection Control in Alternative Health Care Settings

Patients increasingly receive care from a large spectrum of different settings, placing them at risk for exposure to pathogens by many different sources. Each health care environment has its own specific challenges, and thus infection control programs must be tailored to each specific setting. High-turnover outpatient settings may require additional considerations, such as establishing patient triage and follow-up protocols, and broadened cleaning and disinfection procedures. In nursing homes, infection control programs should focus on surveillance for infections and antimicrobial resistance, outbreak investigation and control plan for epidemics, isolation precautions, hand hygiene, staff education, and employee and resident health programs.

Decrease of growth, biofilm and secreted virulence in opportunistic nosocomial Pseudomonas aeruginosa ATCC 25619 by glycyrrhetinic acid

The present study elucidates the antibiofilm and antivirulent capability of glycyrrhetinic acid (GRA) against Pseudomonas aeruginosa ATCC 25619. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of GRA against P. aeruginosa were found to be 160 μg/mL and 420 μg/mL respectively. In an acclimatization resistance analysis using P. aeruginosa, no resistance towards GRA was observed during the habituation period. Adequate penetration of GRA over the biofilm matrix was proposed with the membrane penetration model assembly constructed with the preformed biofilm exhibited the prospective penetration of GRA above the mature biofilm. Furthermore, GRA resulted in the attenuation of virulence factors such as motility, biofilm formation, pyocyanin secretion, secreted proteases with its sub MIC concentrations. The antibiofilm property of GRA was assessed with the light microscopy and high content screening fluorescent imaging system, which clearly demonstrates, the thickness of P. aeruginosa biofilm was reduced to 11.33 ± 2.08 μm from 39 ± 2.51 μm. Transmission Electron Microscopy (TEM) images depicted the morphological changes in cells such as disaggregation of colonies, cell disruption with loss of intracellular material, cytolytic damage, the process of morphological transformation, bacteriolysis indicating the potential effect of GRA.

Reduction of methicillin-resistant Staphylococcus aureus infection in long-term care is possible while maintaining patient socialization: A prospective randomized clinical trial

BACKGROUND

Antibiotic resistance is a challenge in long-term care facilities (LTCFs). The objective of this study was to demonstrate that a novel, minimally invasive program not interfering with activities of daily living or socialization could lower methicillin-resistant Staphylococcus aureus (MRSA) disease.

METHODS

This was a prospective, cluster-randomized, nonblinded trial initiated at 3 LTCFs. During year 1, units were stratified by type of care and randomized to intervention or control. In year 2, all units were converted to intervention consisting of universal decolonization using intranasal mupirocin and a chlorhexidine bath performed twice (2 decolonization-bathing cycles 1 month apart) at the start of the intervention period. Subsequently, after initial decolonization, all admissions were screened on site using real-time polymerase chain reaction, and those MRSA positive were decolonized, but not isolated. Units received annual instruction on hand hygiene. Enhanced bleach wipe cleaning of flat surfaces was done every 4 months.

RESULTS

There were 16,773 tests performed. The MRSA infection rate decreased 65% between baseline (44 infections during 365,809 patient days) and year 2 (12 infections during 287,847 patient days; P <.001); a significant reduction was observed at each of the LTCFs (P <.03).

CONCLUSIONS

On-site MRSA surveillance with targeted decolonization resulted in a significant decrease in clinical MRSA infection among LTCF residents.

Identifying conditions for elimination and epidemic potential of methicillin-resistant Staphylococcus aureus in nursing homes

BACKGROUND

Residents of nursing homes are commonly colonized with methicillin-resistant Staphylococcus aureus (MRSA) but there is a limited understanding of the dynamics and determinants of spread in this setting. To address this gap, we sought to use mathematical modeling to assess the epidemic potential of MRSA in nursing homes and to determine conditions under which non-USA300 and USA300 MRSA could be eliminated or reduced in the facilities.

METHODS

Model parameters were estimated from data generated during a longitudinal study of MRSA in 6 Wisconsin nursing homes. The data included subject colonization status with strain-specific MRSA collected every 3 months for up to 1 year. Deterministic and stochastic co-colonization and single-strain models were developed to describe strain-specific dynamics of MRSA in these facilities. Basic reproduction numbers of strain-independent MRSA, non-USA300 and USA300 MRSA were estimated numerically. The impact of antibiotic use in the past 3 months on the prevalence of strain-specific MRSA and associated basic reproduction numbers were evaluated.

RESULTS

Our models predicted that MRSA would persist in Wisconsin nursing homes, and non-USA300 would remain the dominant circulating strain. MRSA eradication was theoretically achievable by elimination of MRSA-positive admissions over the course of years. Substantial reductions in MRSA prevalence could be attained through marked increase in clearance rates or reduction in MRSA-positive admissions sustained over years. The basic reproduction number of strain-independent MRSA was 0.18 (95 % CI = 0.13-0.23). Recent antibiotic use increased the prevalence of strain-specific MRSA and associated basic reproduction numbers, but was unlikely to lead to an outbreak.

CONCLUSIONS

Based on our model, MRSA elimination from nursing homes, while theoretically possible, was unlikely to be achieved in practice. Decolonization therapy that can sustain higher clearance rates or lower MRSA-positive introductions over years may reduce strain-specific prevalence of MRSA in the facilities, and antibiotic stewardship may contribute to this effort. Large-scale MRSA outbreaks were unlikely in this setting.

Infection Control in Alternative Health Care Settings: An Update

With changing health care delivery, patients receive care at various settings including acute care hospitals, nursing homes, outpatient primary care and specialty clinics, and at home, exposing them to pathogens in various settings. Various health care settings face unique challenges, requiring individualized infection control programs. Infection control programs in nursing homes should address surveillance for infections and antimicrobial resistance, outbreak investigation and control plan for epidemics, isolation precautions, hand hygiene, staff education, and employee and resident health programs.

Impact of Detection, Education, Research and Decolonization without Isolation in Long-term care (DERAIL) on methicillin-resistant Staphylococcus aureus colonization and transmission at 3 long-term care facilities

We tested infection prevention strategies to limit exposure of long-term care facility residents to drug-resistant pathogens in a prospective, cluster randomized 2-year trial involving 3 long-term care facilities (LTCFs) using methicillin-resistant Staphylococcus aureus (MRSA) as a model. We hypothesized that nasal MRSA surveillance using rapid quantitative polymerase chain reaction and decolonization of carriers would successfully lower overall MRSA colonization. In year 1, randomly assigned intervention units received decolonization with nasal mupirocin and chlorhexidine bathing and enhanced environmental cleaning with bleach every 4 months. Newly admitted MRSA nares-positive residents were decolonized on admission. Control units were screened but not decolonized. All units received periodic bleach environmental cleaning and instruction on hand hygiene. In year 2, all units followed intervention protocol caused by failure of the cluster randomized approach to sufficiently segregate patients. MRSA colonization was monitored using point prevalence testing every 4-6 months. Colonization status at admission and discharge was performed 1 quarter per year to determine acquisition. Fisher exact test was used for statistical analysis. Baseline MRSA colonization rate was 16.64%. In year 1, the colonization rate of intervention units was 11.61% (P = .028) and 17.85% in control units (P = .613) compared with baseline. Intervention unit rate difference compared with the controls was significant (P = .001). In year 2, the colonization rate was 10.55% (P < .001) compared with baseline. The transmission rates were 1.66% and 3.52% in years 1 and 2, respectively (P = .034). The planned interventions of screening and decolonization were successful at lowering MRSA colonization.

Protective effect of methicillin-susceptible Staphylococcus aureus carriage against methicillin-resistant S. aureus acquisition in nursing homes: a prospective cross-sectional study

OBJECTIVE

To evaluate whether an ecologic inverse association exists between methicillin-susceptible Staphylococcus aureus (MSSA) prevalence and methicillin-resistant S. aureus (MRSA) prevalence in nursing homes.

METHODS

We conducted a secondary analysis of a prospective cross-sectional study of S. aureus prevalence in 26 nursing homes across Orange County, California, from 2008-2011. Admission prevalence was assessed using bilateral nares swabs collected from all new residents within 3 days of admission until 100 swabs were obtained. Point prevalence was assessed from a representative sample of 100 residents. Swab samples were plated on 5% sheep blood agar and Spectra MRSA chromogenic agar. If MRSA was detected, no further tests were performed. If MRSA was not detected, blood agar was evaluated for MSSA growth. We evaluated the association between MRSA and MSSA admission and point prevalence using correlation and linear regression testing.

RESULTS

We collected 3,806 total swabs. MRSA and MSSA admission prevalence were not correlated (r = -0.40, P = .09). However, MRSA and MSSA point prevalence were negatively correlated regardless of whether MSSA prevalence was measured among all residents sampled (r = -0.67, P = .0002) or among those who did not harbor MRSA (r = -0.41, P = .04). This effect persisted in regression models adjusted for the percentage of residents with diabetes (β = -0.73, P = .04), skin lesions (β = -1.17, P = .002), or invasive devices (β = -1.4, P = .0006).

CONCLUSIONS

The inverse association between MRSA and MSSA point prevalence and minimal association on admission prevalence suggest MSSA carriage may protect against MRSA acquisition in nursing homes. The minimal association on admission prevalence further suggests competition may occur during nursing home stays.

Methicillin-resistant Staphylococcus aureus prevention practices in hospitals throughout a rural state

BACKGROUND

The Institute for Healthcare Improvement (IHI) created an evidence-based bundle to help reduce methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections. The study aim was to identify which components of the IHI's MRSA bundle that rural hospitals have implemented and to identify barriers that hindered implementation of bundle components.

METHODS

Four surveys about the IHI's MRSA bundle were administered at the Iowa Statewide Infection Prevention Seminar between 2007 and 2011. Surveys were mailed to infection preventionists (IPs) who did not attend the meetings.

RESULTS

The percentage of IPs reporting that their hospital implemented a hand hygiene program (range by year, 87%-94%) and used contact precautions for patients infected (range by year, 97%-100%) or colonized (range by year, 77%-92%) with MRSA did not change significantly. The number of hospitals that monitored the effectiveness of environmental cleaning significantly increased from 23%-71% (P < .01). Few hospitals assessed daily if central lines were necessary (range by year, 22%-26%). IPs perceived lack of support to be a major barrier to implementing bundle components.

CONCLUSION

Most IPs reported that their hospitals had implemented most components of the MRSA bundle. Support within the health care system is essential for implementing each component of an evidence-based bundle.

Screening for methicillin-resistant Staphylococcus aureus: a comparative effectiveness review

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is an important cause of health care-associated infections. Although the evidence in support of MRSA screening has been promising, a number of questions remain about the effectiveness of active surveillance.

METHODS

We searched the literature for studies that examined MRSA acquisition, MRSA infection, morbidity, mortality, harms of screening, and resource utilization when screening for MRSA carriage was compared with no screening or with targeted screening. Because of heterogeneity of the data and weaknesses in study design, meta-analysis was not performed. Strength of evidence (SOE) was determined using the system developed by the Grading of Recommendations Assessment, Development and Evaluation Working Group.

RESULTS

One randomized controlled trial and 47 quasi-experimental studies met our inclusion criteria. We focused on the 14 studies that addressed health care-associated outcomes and that attempted to control for confounding and/or secular trends, because those studies had the potential to support causal inferences. With universal screening for MRSA carriage compared with no screening, 2 large quasi-experimental studies found reductions in health care-associated MRSA infection. The SOE for this finding is low. For each of the other screening strategies evaluated, this review found insufficient evidence to determine the comparative effectiveness of screening.

CONCLUSIONS

Although there is low SOE that universal screening of hospital patients decreases MRSA infection, there is insufficient evidence to determine the consequences of universal screening or the effectiveness of other screening strategies.

Tea tree oil (5%) body wash versus standard care (Johnson's Baby Softwash) to prevent colonization with methicillin-resistant Staphylococcus aureus in critically ill adults: a randomized controlled trial

OBJECTIVES

To determine whether the daily use of 5% tea tree oil (TTO) body wash (Novabac 5% Skin Wash) compared with standard care [Johnson's Baby Softwash (JBS)] had a lower incidence of methicillin-resistant Staphylococcus aureus (MRSA) colonization.

PATIENTS

The study setting was two intensive care units (ICUs; mixed medical, surgical and trauma) in Northern Ireland between October 2007 and July 2009. The study population comprised 391 patients who were randomized to JBS or TTO body wash.

METHODS

This was a Phase 2/3, prospective, open-label, randomized, controlled trial.

TRIAL REGISTRATION

ISRCTN65190967. The primary outcome was new MRSA colonization during ICU stay. Secondary outcomes included the incidence of MRSA bacteraemia and maximum increase in sequential organ failure assessment score.

RESULTS

A total of 445 patients were randomized to the study. After randomization, 54 patients were withdrawn; 30 because of a positive MRSA screen at study entry, 11 due to lack of consent, 11 were inappropriately randomized and 2 had adverse reactions. Thirty-nine (10%) patients developed new MRSA colonization (JBS n = 22, 11.2%; TTO body wash n = 17, 8.7%). The difference in percentage colonized (2.5%, 95% CI - 8.95 to 3.94; P = 0.50) was not significant. The mean maximum increase in sequential organ failure assessment score was not significant (JBS 1.44, SD 1.92; TTO body wash 1.28, SD 1.79; P = 0.85) and no study patients developed MRSA bacteraemia.

CONCLUSIONS

Compared with JBS, TTO body wash cannot be recommended as an effective means of reducing MRSA colonization.

Staphylococcal decolonisation: an effective strategy for prevention of infection?

Staphylococcus aureus decolonisation--treatment to eradicate staphylococcal carriage--is often considered as a measure to prevent S aureus infection. The most common approach to decolonisation has been intranasal application of mupirocin either alone or in combination with antiseptic soaps or systemic antimicrobial agents. Some data support the use of decolonisation in surgical patients colonised with S aureus, particularly in those undergoing cardiothoracic procedures. Although this intervention has been associated with low rates of postoperative S aureus infection, whether overall rates of infection are also decreased is unclear. Patients undergoing chronic haemodialysis or peritoneal dialysis might benefit from decolonisation, although repeated courses of treatment are needed, and the effects are modest. Eradication of meticillin-resistant S aureus (MRSA) carriage has generally been difficult, and the role of decolonisation as an MRSA infection control measure is uncertain. The efficacy of decolonisation of patients with community-associated MRSA has not been established, and the routine use of decolonisation of non-surgical patients is not supported by data.

The challenge of methicillin-resistant Staphylococcus aureus prevention in hemodialysis therapy

Methicillin-resistant Staphylococcus aureus (MRSA) infections have challenged care process and resource utilization in the acute hospital care setting for nearly 30 years. These infections have become important causes of morbidity, mortality, and a source of concern in the primary and emergency care context over the past decade. As individuals receiving recurrent therapy with features of both ambulatory care and acute care, hemodialysis patients are exposed to numerous opportunities for MRSA acquisition. Surprisingly, high prevalence rates for MRSA colonization have been demonstrated for both hemodialysis patients and their care providers. The necessity of vascular access and the persistent high prevalence of endovascular catheter use among patients repeatedly exposed to healthcare settings provide the perfect milieu for the troubling rates of MRSA infection, particularly bloodstream infections, in outpatient dialysis care. Dialysis industry shifts, including increased requirements for compliance and reporting in other areas of dialysis care, tax resources for infection prevention processes. Multifaceted strategies that include reassessment of vascular access care, attention to the interruption of MRSA transmission dynamics, and emphasis on organizational learning processes are needed to accomplish a meaningful reduction in the morbidity, mortality, and cost associated with MRSA infections in dialysis care.

Effects of Melaleuca alternifolia (tea tree) essential oil and the major monoterpene component terpinen-4-ol on the development of single- and multistep antibiotic resistance and antimicrobial susceptibility

This study examined the effect of subinhibitory Melaleuca alternifolia (tea tree) essential oil on the development of antibiotic resistance in Staphylococcus aureus and Escherichia coli. Frequencies of single-step antibiotic-resistant mutants were determined by inoculating bacteria cultured with or without subinhibitory tea tree oil onto agar containing 2 to 8 times the MIC of each antibiotic and with or without tea tree oil. Whereas most differences in resistance frequencies were relatively minor, the combination of kanamycin and tea tree oil yielded approximately 10-fold fewer resistant E. coli mutants than kanamycin alone. The development of multistep antibiotic resistance in the presence of tea tree oil or terpinen-4-ol was examined by culturing S. aureus and E. coli isolates daily with antibiotic alone, antibiotic with tea tree oil, and antibiotic with terpinen-4-ol for 6 days. Median MICs for each antibiotic alone increased 4- to 16-fold by day 6. Subinhibitory tea tree oil or terpinen-4-ol did not greatly alter results, with day 6 median MICs being either the same as or one concentration different from those for antibiotic alone. For tea tree oil and terpinen-4-ol alone, day 6 median MICs had increased 4-fold for S. aureus (n = 18) and 2-fold for E. coli (n = 18) from baseline values. Lastly, few significant changes in antimicrobial susceptibility were seen for S. aureus and S. epidermidis isolates that had been serially subcultured 14 to 22 times with subinhibitory terpinen-4-ol. Overall, these data indicate that tea tree oil and terpinen-4-ol have little impact on the development of antimicrobial resistance and susceptibility.

Conceptual model for reducing infections and antimicrobial resistance in skilled nursing facilities: focusing on residents with indwelling devices

Infections in skilled nursing facilities (SNFs) are common and result in frequent hospital transfers, functional decline, and death. Colonization with multidrug-resistant organisms (MDROs) - including methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and multidrug-resistant gram-negative bacilli (R-GNB) - is also increasingly prevalent in SNFs. Antimicrobial resistance among common bacteria can adversely affect clinical outcomes and increase health care costs. Recognizing a need for action, legislators, policy-makers, and consumer groups are advocating for surveillance cultures to identify asymptomatic patients with MDROs, particularly MRSA in hospitals and SNFs. Implementing this policy for all SNF residents may be costly, impractical, and ineffective. Such a policy may result in a large increase in the number of SNF residents placed in isolation precautions with the potential for reduced attention by health care workers, isolation, and functional decline. Detection of colonization and subsequent attempts to eradicate selected MDROs can also lead to more strains with drug resistance. We propose an alternative strategy that uses a focused multicomponent bundle approach that targets residents at a higher risk of colonization and infection with MDROs, specifically those who have an indwelling device. If this strategy is effective, similar strategies can be studied and implemented for other high-risk groups.

Uncontrolled, open-label, pilot study of tea tree (Melaleuca alternifolia) oil solution in the decolonisation of methicillin-resistant Staphylococcus aureus positive wounds and its influence on wound healing

Many complementary and alternative products are used to treat wounds. The essential oil of Melaleuca alternifolia, tea tree oil, has proven antimicrobial and anti-inflammatory properties, may be useful in methicillin-resistant Staphylococcus aureus (MRSA) decolonisation regimens and is reputed to have 'wound-healing' properties, but more data are required to support these indications. The primary aim of this uncontrolled case series was to assess whether a tea tree oil solution used in a wound cleansing procedure could decolonise MRSA from acute and chronic wounds of mixed aetiology. The secondary aim was to determine if the tea tree oil solution influenced wound healing outcomes. Nineteen participants with wounds suspected of being colonised with MRSA were enrolled in a pilot study. Seven were subsequently shown not to have MRSA and were withdrawn from the study. As many as 11 of the remaining 12 participants were treated with a water-miscible tea tree oil (3·3%) solution applied as part of the wound cleansing regimen at each dressing change. Dressing changes were three times per week or daily as deemed necessary by the study nurse following assessment. One participant withdrew from the study before treatment. No participants were MRSA negative after treatment. After treatment had been implemented, 8 of the 11 treated wounds had begun to heal and reduced in size as measured by computer planimetry. Although this formulation and mode of delivery did not achieve the primary aim of the study, tea tree oil did not appear to inhibit healing and the majority of wounds reduced in size after treatment.

Association of high-level mupirocin resistance and multidrug-resistant methicillin-resistant Staphylococcus aureus at an academic center in the midwestern United States

Mupirocin is a topical antimicrobial used to eradicate methicillin-resistant Staphylococcus aureus (MRSA) colonization, usually in the absence of susceptibility testing. We hypothesized that high-level (HL) mupirocin resistance was associated with multidrug resistance (MDR). To this end, unique patient isolates identified at our institution during 2008 were stratified into those resistant to ≥ 3 non-β-lactam antimicrobial classes (MDR) and non-MDR MRSA. HL mupirocin resistance was screened by mupA PCR on all MDR isolates (n = 191) and a 20% random sample (n = 130) of non-MDR isolates; E-testing confirmed HL resistance. We found that among MDR isolates, 13 (6.8%) carried mupA, whereas none of the non-MDR isolates did (P = 0.001). Thus, although the overall prevalence of HL mupirocin resistance is low among MRSA isolates at our institution, an association exists between mupA carriage and MDR. Using genotyping and antimicrobial susceptibility profiling, we identified nine HL mupirocin-resistant clones. Whereas the majority of mupA-negative MDR isolates had a health care-associated MRSA (HA-MRSA) genotype (multilocus sequence type 5 [ST5] or SCCmec type II), the majority of mupA-positive MDR isolates had a community-associated MRSA (CA-MRSA) genotype (ST8 or SCCmec type IV). However, CA- and HA-MRSA genotypes were more evenly distributed among mupA-positive isolates compared to mupA-negative MDR isolates. Thus, in Chicago, mupA is circulating among both CA- and HA-MRSA backgrounds.