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.

Utility of Methicillin-Resistant Staphylococcus aureus Nares Screening in Hospitalized Children with Acute Infectious Disease Syndromes

Studies in adults support the use of a negative methicillin-resistant Staphylococcus aureus (MRSA) nares screening (MNS) to help limit empiric anti-MRSA antibiotic therapy. We aimed to evaluate the use of MNS for anti-MRSA antibiotic de-escalation in hospitalized children (<18 years). Records of patients admitted between 1 January 2015 and 31 December 2020 with a presumed infectious diagnosis who were started on anti-MRSA antibiotics, had a PCR-based MNS, and a clinical culture performed were retrospectively reviewed. A total of 95 children were included with a median age (range) of 2 (0–17) years. The top three diagnosis groups were skin and soft tissue infections (n = 38, 40%), toxin-mediated syndromes (n = 17, 17.9%), and osteoarticular infections (n = 14, 14.7%). Nasal MRSA colonization and growth of MRSA in clinical cultures was found in seven patients (7.4%) each. The specificity and the negative predictive value (NPV) of the MNS to predict a clinical MRSA infection were both 95.5%. About half (n = 55, 57.9%) had anti-MRSA antibiotics discontinued in-house. A quarter (n = 14, 25.5%) were de-escalated based on the negative MNS test alone, and another third (n = 21, 38.2%) after negative MNS test and negative culture results became available. A high NPV suggests that MNS may be useful for limiting unnecessary anti-MRSA therapy and thereby a useful antimicrobial stewardship tool for hospitalized children. Prospective studies are needed to further characterize the utility of MNS for specific infectious diagnoses.

79. Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal PCR Assays Beyond Respiratory Infections

Background Empiric use of vancomycin is common in clinical practice. Currently there is strong evidence to support the use of MRSA nasal screening to predict the absence of MRSA in respiratory infections; however, minimal data exists regarding its utility as a de-escalation tool beyond pulmonary indications. Furthermore, MRSA nasal PCR has been shown to be a more efficient way to detect the presence of MRSA colonization than traditional culture methods. The purpose of this study was to evaluate the correlation between results of MRSA nasal PCR assays and blood or bone/soft tissue cultures. Methods This was a retrospective study of patients who presented to any of three hospitals part of an integrated health system in Des Moines, Iowa, from March 1, 2019 to February 29, 2020. Included patients were those who underwent MRSA nasal PCR screening and had a clinical culture (blood, bone, tissue, deep podiatric wound, joint aspirate, or synovial fluid) obtained within 3 days of the MRSA nasal PCR. Data on age, sex, diabetes mellitus and dialysis were collected. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for all cultures, and blood and bone/soft tissue cultures separately were estimated. Results A total of 1989 patients were included in the study. Of these patients, 1953 patients had a blood culture obtained and 171 patients had a bone/soft tissue culture obtained. The median age was 66 years, and 1086 (54.6%) patients were male. At baseline, 33.1% and 3.8% of patients had diabetes or were on dialysis, respectively. The overall prevalence of MRSA colonization was 12.3%. The sensitivities of the MRSA nasal PCR screening were 67.5% for all clinical cultures, 81.8% for blood cultures, and 55% for bone/soft tissue cultures. Specificities were 88.8%, 88.5%, and 92.7% for all cultures, blood cultures, and bone/soft tissue cultures, respectively. The PPVs were 11%, 7.5%, and 50% for all cultures, blood cultures, and bone/soft tissue cultures, respectively, and the NPVs were 99.3%, 99.8%, and 92.7%, respectively. Conclusion MRSA nasal PCR screening showed high NPV across blood and bone/soft tissue cultures. These results indicate the clinical utility of MRSA nasal PCR assays beyond respiratory infections and can further support antimicrobial stewardship activities. Disclosures All Authors: No reported disclosures

1141. Effect of the SARS-CoV-2 Pandemic on Staphylococcus aureus Colonization in Healthy Children

Background Staphylococcus aureus is a common colonizer of the skin and mucus membranes. Several investigators have reported reductions in a number of childhood infections temporally associated with social distancing/masking mandates intended to curb the SARS-CoV-2 pandemic. No data are available regarding the impact of these measures on bacterial colonization. We report preliminary results from an ongoing longitudinal S. aureus colonization study initiated just prior to the pandemic. Methods Healthy children &lt; 18 years were recruited from 2 Houston-area primary care clinics from Nov 2019- Feb 2020. Subjects had anterior nares and axillary cultures obtained and completed questionnaires. Additional questionnaires and cultures were performed every three months for 1 year. Identified S. aureus were subjected to antimicrobial susceptibility testing as well as PCR for genes associated with tolerance to antiseptics (qacA/B, smr). Beginning in March 2020, social distancing and masking mandates were initiated. Temporary restrictions on non-essential research activities were enacted and follow-up encounters were not resumed until June 2020; subjects completed follow-up by Feb 2021. Comparison of colonization rates pre- and post-SARS-CoV-2 pandemic were performed. Results 168 children were enrolled and 75.6% completed at least 2 follow-up encounters. 51.2% were colonized at least once by S. aureus and 8.1% had MRSA colonization (Figure 1). Those with MRSA colonization were older than those without (9.6 vs. 5.8 years, p=0.04). The frequency of S. aureus colonization was stable during the study period; however, rates of MRSA colonization declined beginning in summer 2020 (Figure 2 and 3, p=0.04). There was no difference in self-reported masking/social distancing practices or any traditional MRSA risk factors among those with and without MRSA colonization in the 6-12 month follow-up period. The proportion of children colonized at least once during the course of the study period. The proportion of children colonized with S. aureus at each given time point. The dashed vertical line corresponds to initiation of physical distancing/masking mandates in our region The proportion of children colonized with MRSA at each given time point. The dashed vertical line corresponds to initiation of physical distancing/masking mandates in our region Conclusion Overall S. aureus nasal and axillary colonization in children remained relatively constant in the pre- and post-SARS-CoV-2 pandemic. A temporal association with social distancing/masking mandates and reduced MRSA colonization was observed. These findings suggest the potential impacts aggressive infection control practices may have on community MRSA colonization. Disclosures Jonathon C. McNeil, MD, Agency for Healthcare Research and Quality (Research Grant or Support)Allergan (Grant/Research Support)Nabriva (Grant/Research Support, Other Financial or Material Support, Site PI for a multicenter trial) Anthony R. Flores, MD, MPH, PhD, Nothing to disclose

Methicillin-resistant Staphylococcus aureus colonization among healthcare workers in Oman

Introduction: Methicillin-Resistant Staphylococcus aureus (MRSA) is a S. aureus strain characterized by resistance to cloxacillin. Healthcare workers (HCWs), are recognized for their heightened risk for MRSA acquisition and possibly for MRSA nosocomial transmission. This cross-sectional study aimed to determine the prevalence and the associated risk factors of MRSA colonization among healthcare workers at Sultan Qaboos University Hospital (SQUH) in Oman. Methodology: A total of 200 nasal swab samples were collected from the healthcare workers at SQUH during the period October 2nd 2018 to January 7th 2019. All nasal swab samples were examined microbiologically for the presence of MRSA using the standard method and the results were confirmed by detection of the mecA product (PBP2a). Data on associated risk factors for MRSA colonization was collected and analyzed. Results: Forty-one of the 200 screened healthcare workers (20.5%) were found to have nasal carriage of Staphylococcus aureus of which 63.4% were Methicillin Sensitive and 36.6% were Methicillin-Resistant (MRSA). Methicillin-Resistant Staphylococcus aureus (MRSA) was isolated from fifteen of the 200 screened healthcare workers giving a prevalence rate of nasal colonization with MRSA of 7.5%. We found no statistical association between healthcare worker MRSA nasal colonization and age, gender, HCWs specialty, hand hygiene practices, skin condition, previous MRSA infection, and previous exposure to antibiotics. Conclusions: Identification of the prevalence and the associated risk factors of MRSA colonization in healthcare workers mandates continuous surveillance and the implementation of all possible preventive measures to reduce re-occurrences.

Transfer of methicillin-resistant Staphylococcus aureus by fist bump versus elbow bump

For 40 patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, fist bump and elbow bump greetings resulted in frequent transfer of MRSA (25% vs 15%, respectively), but significantly fewer colonies were transferred via the elbow bump. Noncontact greetings should be encouraged to reduce the risk of transfer of healthcare-associated pathogens.

Methicillin-resistant Staphylococcus aureus among healthcare workers: screening, risk factors and treatment

Methicillin-resistant Staphylococcus aureus (MRSA) is a common pathogen of clinical significance within the community and healthcare settings. It has been reported with a variety of infections, including endocarditis, bloodstream infections, pneumonia, joint and bone infections, and soft tissue and skin infections. Although many efforts have been exerted to eradicate the rates of infections and studies have reported a decreasing pattern in the prevalence rates over the years, it has been demonstrated that MRSA represents a significant challenge to the healthcare systems and the affected patients. In this literature review, we have provided a discussion regarding the risk factors, screening, and treatment of MRSA among healthcare workers (HCWs) based on the evidence obtained from the current relevant studies in the literature. HCWs are at increased risk of MRSA colonization, and many risk factors have been identified. These mainly include poor hygiene practices, chronic skin diseases, and having a history of working in an MRSA-endemic country. Decolonization practices are the main line of treatment of MRSA colonization among HCWs because antibiotic therapy is usually of limited use because of the increasing resistance to a wide range of antibiotics. Applying adequate interventions as taking care of hand hygiene and using alcohol-based disinfectants is recommended to achieve better outcomes. Increasing awareness among HCWs is also a potential approach to achieve better management.

Understanding short-term transmission dynamics of methicillin-resistant Staphylococcus aureus in the patient room

Objective: Little is known about the short-term dynamics of methicillin-resistant Staphylococcus aureus (MRSA) transmission between patients and their immediate environment. We conducted a real-life microbiological evaluation of environmental MRSA contamination in hospital rooms in relation to recent patient activity. Design: Observational pilot study. Setting: Two hospitals, hospital 1 in Zurich, Switzerland, and hospital 2 in Ann Arbor, Michigan, United States. Patients: Inpatients with MRSA colonization or infection. Methods: At baseline, the groin, axilla, nares, dominant hands of 10 patients and 6 environmental high-touch surfaces in their rooms were sampled. Cultures were then taken of the patient hand and high-touch surfaces 3 more times at 90-minute intervals. After each swabbing, patients’ hands and surfaces were disinfected. Patient activity was assessed by interviews at hospital 1 and analysis of video footage at hospital 2. A contamination pressure score was created by multiplying the number of colonized body sites with the activity level of the patient. Results: In total, 10 patients colonized and/or infected with MRSA were enrolled; 40 hand samples and 240 environmental samples were collected. At baseline, 30% of hands and 20% of high-touch surfaces yielded MRSA. At follow-up intervals, 8 (27%) of 30 patient hands, and 10 (6%) of 180 of environmental sites were positive. Activity of the patient explained 7 of 10 environmental contaminations. Patients with higher contamination pressure score showed a trend toward higher environmental contamination. Conclusion: Environmental MRSA contamination in patient rooms was highly dynamic and was likely driven by the patient’s MRSA body colonization pattern and the patient activity.

The Active Surveillance of Staphylococcus aureus using Polymerase Chain Reaction-based Identification Method among Hospitalized-patient of Haji Adam Malik General Hospital, Medan, Indonesia

BACKGROUND: Active surveillance of methicillin-resistant Staphylococcus aureus (MRSA) carriers is associated with the lower incidence of bacteremia and lower mortality rates throughout literature; yet, this important step still remains problematic for developing countries, particularly Indonesia. AIM: The study aimed to demonstrate MRSA colonization rate in Haji Adam Malik Hospital, Medan, Indonesia. MATERIALS AND METHODS: The study enrolled 200 mucocutaneous isolates obtained from hospitalized patients during a 1-year period of study (2018). VITEK-2 system in addition to standard bacterial identification, such as gram staining, latex agglutination test, and hemolysis pattern, was performed to select S. aureus colonies in two different laboratories, Microbiology laboratory of Haji Adam Malik General Hospital and Multidisciplinary Laboratory, Faculty of Medicine, Universitas Sumatera Utara, for polymerase chain reaction (PCR) examination. RESULTS: Based on the VITEK-2 system preliminary identification, there were 80 S. aureus colonies which then underwent PCR examination. Through standard PCR assay, there were 32 bacterial isolates contained the mecA gene and it can be determined MRSA colonization rate of the hospital was 16% with consistent results of standard bacterial identification. CONCLUSIONS: Active surveillance of MRSA carriers is mandatory and urged it as a regular program in a hospital setting to decrease MRSA transmission rate.

Nasal Carriage of Methicillin-Resistant Staphylococcus aureus among Healthcare Workers in a Tertiary Care Hospital, Kathmandu, Nepal

Introduction. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common causes of nosocomial infections. One of the potential risk factors for nosocomial staphylococcal infections is colonization of the anterior nares of healthcare workers (HCWs). Our study aimed to determine the rate of nasal carriage MRSA among HCWs at Manmohan Memorial Medical College and Teaching Hospital, Kathmandu. Methods. Two hundred and thirty-two nasal swabs were collected from HCWs of Manmohan Memorial Medical College and Teaching Hospital, Kathmandu, Nepal, within six months (February 2018–July 2018). Nasal swabs were cultured, and S. aureus isolates were subjected to the antimicrobial susceptibility test by the modified Kirby–Bauer disc diffusion method. MRSA and iMLSB (inducible macrolide lincosamide streptogramin B) resistance was screened using the cefoxitin disc (30 μg) and D-test (clindamycin and erythromycin sensitivity pattern), respectively, following CLSI (Clinical and Laboratory Standard Institute) guidelines. Risk factors for MRSA colonization were determined using the chi-square test considering the p value ˂0.05 as significant. Results. A total of 34/232 (14.7%) S. aureus were isolated, out of which 12 (35.3%) were MRSA. The overall rate of nasal carriage MRSA among HCWs was 5.2% (12/232). Colonization of MRSA was higher in males (8.7%) than in females (4.3%). MRSA colonization was found to be at peak among the doctors (11.4%). HCWs of the postoperative ward were colonized highest (18.2%). All MRSA isolates were sensitive to linezolid and tetracycline. iMLSB resistance was shown by 7(20.6%) of the isolates. MRSA strains showed higher iMLSB resistance accounting for 33.3% (4/12) in comparison to methicillin-susceptible strains with 13.6% (3/22). Smoking was found to be significantly associated with MRSA colonization ( p = 0.004 ). Conclusion. Rate of nasal carriage MRSA is high among HCWs and hence needs special attention to prevent HCW-associated infections that may result due to nasal colonization.