Methicillin-resistant Staphylococcus Aureus Outbreak Research Articles

Epidemiologic and Molecular Investigation of a MRSA Outbreak Caused by a Contaminated Bathtub for Carbon Dioxide Hydrotherapy and Review of the Literature.

Methods We conducted an outbreak investigation and performed a molecular typing of the outbreak strains with pulsed-field gel electrophoresis (PFGE). In addition, we reviewed PubMed and the Outbreak Database for MRSA outbreaks related to hydrotherapy or other bathing activities. Results Four patients acquired nosocomial MRSA during the 4-week outbreak period. Environmental sampling revealed the presence of MRSA in the bathtub used for hydrotherapy. The environmental and the patients' isolates showed an indistinguishable restriction pattern in the PFGE. Subsequent discontinuation of bathing stopped the outbreak. The literature search found 9 MRSA outbreak reports related to bathing activities or hydrotherapy. Conclusion The epidemiologic outbreak investigation together with the molecular findings suggests monoclonal spread of MRSA due to surface contamination of the bathtub. After enhancing the disinfection and cleaning process accompanied by staff training with respect to hand hygiene, no further cases occurred. Standardized and best practice cleaning and disinfection protocols are crucial, especially in critical facilities such as hydrotherapy units. Regular environmental sampling is helpful to monitor these processes and to detect potential contamination.

Long-Term Outcome of Infection Control for Methicillin-Resistant <i>Staphylococcus aureus</i> and Kaizen Approach with Problem-Solving

Background: Methicillin-resistant Staphylococcus aureus (MRSA) results in longer hospitalization, increased expenses, and poorer patient prognosis. The aim of this study is 1) to investigate the short-term outcome of MRSA outbreak and the prevention in our surgical ward, and 2) to evaluate the long-term outcome of a 7-year experience of infection control, and 3) to report the effectiveness of intervention of quality improvement by industry problem-solving method for the eradication of a new occurrence of MRSA patients. Methods: Between April 2009 and October 2019, we retrospectively studied the improvement activity for infection control and preventative measures in our surgical ward. The daily alcohol use for hand hygiene was measured (ml/patient/day) and the monthly number of occurrences of new MRAS patients was investigated. We used the industry problem-solving method as the Kaizen of infection control for the eradication of a new Methicillin-resistant Staphylococcus aureus occurrence in the surgical ward. Results: There was an inverse correlation between the increased amount of alcohol use for hand hygiene and the decreased number of new MRSA patients. In the long-term outcome, the amount of alcohol use has gradually decreased and the MRSA patients have been occasionally observed; these facts should display the difficulty to maintain a strict infection control. By the use of the problem-solving method, there continued for 7 months no new MRSA patients between June 2018 and December 2018. However, once the amount of alcohol use for hand hygiene decreased below 40 ml/patient/day, three new MRSA patients were detected. It displayed an inverse correlation between the decreased amount of alcohol use for hand hygiene and the increased number of new MRSA patients. Conclusion: The daily monitoring and measuring of the amount of alcohol use for hand hygiene and to know the current number of new occurrence of MRSA patients will become a meaningful tool. By performing the Kaizen with a problem-solving method, it will contribute to the multi-professional team to visualize the process of quality improvement for infection control.

MRSA outbreak in a tertiary neonatal intensive care unit in Iceland

Introduction: Preventing the spread of methicillin-resistant Staphylococcus aureus (MRSA) and understanding the pathophysiology and transmission is essential. This study describes an MRSA outbreak in a neonatal intensive care unit in Reykjavik, Iceland at a time where no screening procedures were active.Materials and methods: After isolating MRSA in the neonatal intensive care unit in 2015, neonates, staff members and parents of positive patients were screened and environmental samples collected. The study period was from 14 April 2015 until 31 August 2015. Antimicrobial susceptibility testing, spa-typing and whole genome sequencing were done on MRSA isolates.Results: During the study period, 96/143 admitted patients were screened for colonization. Non-screened infants had short admissions not including screening days. MRSA was isolated from nine infants and seven parents. All tested staff members were negative. Eight infants and six parents carried MRSA ST30-IVc with spa-type t253 and one infant and its parent carried MRSA CC9-IVa (spa-type t4845) while most environmental samples were MRSA CC9-IVa (spa-type t4845). Whole genome sequencing revealed close relatedness between all ST30-IVc and CC9-IVa isolates, respectively. All colonized infants received decolonization treatment, but 3/9 were still positive when last sampled.Discussion: The main outbreak source was a single MRSA ST30-IVc (spa-type t253), isolated for the first time in Iceland. A new CC9-IVa (spa-type t4845) was also identified, most abundant on environmental surfaces but only in one patient. The reason for the differences in the epidemiology of the two strains is not clear. The study highlights a need for screening procedures in high-risk settings and guidelines for neonatal decolonization.

Mupirocin: applications and production.

Mupirocin is an antibiotic from monocarboxylic acid class used as antibacterial agent against methicillin-resistant Staphylococcus aureus (MRSA) and can be obtained as a mixture of four pseudomonic acids by Pseudomonas fluorescens biosynthesis. Nowadays improving antibiotics occupies an important place in the pharmaceutical industry as more and more resistant microorganisms are developing. Mupirocin is used to control the MRSA outbreaks, for infections of soft tissue or skin and for nasal decolonization. Due to its wide use without prescription, the microorganism's resistance to Mupirocin increased from up to 81%, thus becoming imperative its control or improvement. As the biotechnological production of Mupirocin has not been previously reviewed, in the present paper we summarize some consideration on the biochemical process for the production of pseudomonic acids (submerged fermentation and product recovery). Different strains of Pseudomonas, different culture medium and different conditions for the fermentation were analysed related to the antibiotics yield and the product recovery step is analysed in relation to the final purity. However, many challenges have to be overcome in order to obtain pseudomonic acid new versions with better properties related to antibacterial activity.

Prospective genomic surveillance of methicillin-resistant Staphylococcus aureus (MRSA) associated with bloodstream infection, England, 1 October 2012 to 30 September 2013.

BackgroundMandatory reporting of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSI) has occurred in England for over 15years. Epidemiological information is recorded, but routine collection of isolates for characterisation has not been routinely undertaken. Ongoing developments in whole-genome sequencing (WGS) have demonstrated its value in outbreak investigations and for determining the spread of antimicrobial resistance and bacterial population structure. Benefits of adding genomics to routine epidemiological MRSA surveillance are unknown.AimTo determine feasibility and potential utility of adding genomics to epidemiological surveillance of MRSA.MethodsWe conducted an epidemiological and genomic survey of MRSA BSI in England over a 1-year period (1 October 2012­–30 September 2013).ResultsDuring the study period, 903 cases of MRSA BSI were reported; 425 isolates were available for sequencing of which, 276 (65%) were clonal complex (CC) 22. Addition of 64 MRSA genomes from published outbreak investigations showed that the study genomes could provide context for outbreak isolates and supported cluster identification. Comparison to other MRSA genome collections demonstrated variation in clonal diversity achieved through different sampling strategies and identified potentially high-risk clones e.g. USA300 and local expansion of CC5 MRSA in South West England.ConclusionsWe demonstrate the potential utility of combined epidemiological and genomic MRSA BSI surveillance to determine the national population structure of MRSA, contextualise previous MRSA outbreaks, and detect potentially high-risk lineages. These findings support the integration of epidemiological and genomic surveillance for MRSA BSI as a step towards a comprehensive surveillance programme in England.

Successful control of a methicillin-resistant Staphylococcus aureus outbreak in a burn intensive care unit by addition of universal decolonization with intranasal mupirocin to basic infection prevention measures

Methicillin-resistant Staphylococcus aureus (MRSA) is frequently implicated in health care-associated outbreaks in burn intensive care units, incurring substantial morbidity and mortality to these high-risk patients and excess costs to health care systems. MRSA health care-associated infections (HAIs) were noted before and after the implementation of basic infection prevention measures and the subsequent implementation of universal decolonization with intranasal mupirocin. Pulsed-field gel electrophoresis was used to determine the relatedness of clinical isolates. A case-control study was conducted to characterize the risk factors for MRSA HAIs. Basic interventions failed to decrease the rate of MRSA HAIs, although compliance with these interventions was high throughout the study. MRSA HAIs decreased from 8.53 HAIs per 1,000 patient days before the implementation of intranasal mupirocin to 3.61 HAIs per 1,000 patient days after the implementation of intranasal mupirocin (P = .033). Pulsed-field gel electrophoresis disclosed 10 unique clones with no large clusters. The case-control study revealed a significant association between MRSA HAIs and lengths of stay, body surface area burned, intubation, pressor requirement, leukocytosis, lactic acidosis, development of pneumonia, MRSA colonization, and death. Basic environmental and behavioral interventions fell short of controlling a low-count, sporadic, and multiclonal MRSA outbreak in the burn intensive care unit of a tertiary medical center. However, the added implementation of universal decolonization with intranasal mupirocin was effective. Burn victims with greater disease severity were at higher risk for MRSA HAIs.

First report on USA300 outbreak in a neonatal intensive care unit detected by polymerase chain reaction-based open reading frame typing in Japan

Outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) in the neonatal intensive care unit (NICU) have been reported worldwide. Some outbreaks were caused by USA300, which is a community-associated MRSA clone. In 2011, polymerase chain reaction-based open reading frame typing (POT) for the initial MRSA isolates from all inpatients was started at the Tokyo Metropolitan Children's Medical Center. From March 2014 to April 2015, a total of 131 MRSA strains were isolated, 104 of which were analyzed as healthcare-associated MRSA. Thirteen stains (12.5%) had a POT number of 106-9-93, which strongly suggested USA300; these included 6 from nasal swabs, 6 from blood cultures and 1 from subcutaneous pus. All the MRSA strains were isolated from patients in the NICU; were typed as sequence type 8, spa type t008, and staphylococcal cassette chromosome type mec IVa; and possessed the lukS-lukF and arginine catabolic mobile element-arcA gene. Pulsed-field gel electrophoresis of all the strains, with USA300-0114 as a reference, showed indistinguishable banding pattern. Based on these results, POT was useful in recognizing this first MRSA outbreak of USA300 in a Japanese NICU and was advantageous in terms of swiftness, less cost and monitoring change of the epidemic MRSA lineage.

Cost analysis of outbreaks with Methicillin-resistant Staphylococcus aureus (MRSA) in Dutch long-term care facilities (LTCF).

ObjectivesHighly resistant microorganisms (HRMOs) are of high concern worldwide and are becoming increasingly less susceptible for antibiotics. To study the cost effectiveness of infection prevention measures in long-term care, it is essential to first fully understand the impact of HRMOs. The objective of this study is to identify the costs associated with outbreaks caused by Methicillin-resistant Staphylococcus aureus (MRSA) in Dutch long-term care facilities (LTCF).MethodsAfter an outbreak of MRSA, Dutch LTCF can submit a reimbursement form to the Dutch Healthcare Authority (“Nederlandse Zorgautoriteit”; NZa) to get a part of the total costs reimbursed. In this study, we requested NZa forms for financial impact analysis. Details regarding the costs of the outbreak have been extracted from these forms and additionally specific LTCF have been visited in person to validate the data.Results34 complete reimbursement forms from the period between 2011 and 2016 were received from the NZa and have been included. The median cost per patient per day was estimated at €83.80, varying between €16.89 and €1,820.09. We validated five reimbursement forms by visiting the facility and recalculating the costs. We found a non-significant positive difference of €26.07 compared with the original data (p = 0.068).ConclusionsThis study is to our knowledge the first to give a national overview of total costs associated with an MRSA outbreak in LTCF in the Netherlands. Overall, costs per patient per day seem lower than in a hospital setting, although total costs are much higher due to the long term of care.

Methicillin-resistant Staphylococcus aureus spreading through medical devices used in nursing care: what can we learn from Portugal?

Background: Presently, Portugal faces the third highest level of Staphylococcus aureus in the European Union, leading to burdensome outcomes for health systems, public institutions, patients and their respective families. A significant contamination rate of portable medical devices used by nurses in direct patient care was identified in four medical wards in a large public tertiary hospital. We described the degree of contamination and investigate associated risk factors. Methods & Materials: Descriptive-correlational and cross-sectional study. The target population corresponds to all nurses who provide direct patient care in the referred settings. Medical devices were swabbed and cultured in Mannitol salt agar (MSA). The obtained isolates were subjected to the latex agglutination test in order to investigate the presence of Staph. aureus. Additional information regarding medical devices management by nurses was collected by individual questionnaire. Data were analyzed with IBM SPSS 20. Results: Between April and June 2017, 383 medical devices carried by 50 nurses in their uniform pockets were tested. The most representative devices were tourniquets (68%), adhesive rolls (56%), scissors (26%) and thermometers (20%). Colonies of Staphylococcus coagulase positive (32%) and negative (27%) were identified, ranging from 1.0 × 101 to > 1.5 × 103 CFU/mL. The highest CFU/mL values were observed in reusable tourniquets and axillary thermometers. Overall, and regarding Staphylococcus isolates, 66.6% were positively identified as Methicillin-resistant Staphylococcus aureus (MRSA). Data retrieved from questionnaires evidences that nurses reuse these devices between patients (100%); commonly share these devices with other healthcare professionals such as other nurses, physicians and assistants (92%), are unaware of clinical guidelines regarding medical devices management (82%); lack infection prevention and control training (42%); and don’t properly clean these devices during patient care (32.7%). Conclusion: Fundamental lack of recurrent training, access to specific institutional guidelines and ineffective management of these devices, including lack of cleaning/disinfection, reuse between procedures/patients and sharing them with other professionals were associated with MRSA. The implementation of pathways for medical device management, mandatory staff training and introduction of single-use medical devices in medical wards are recommended to prevent/control future MRSA outbreaks.

A Sporadic Four-Year Hospital Outbreak of a ST97-IVa MRSA With Half of the Patients First Identified in the Community.

This study describes a sporadically occurring 4-year outbreak of methicillin-resistant Staphylococcus aureus (MRSA) originating from a surgical ward. Whole-genome sequencing (WGS) identified the outbreak clone as spa type t267, sequence type ST97, and SCCmec IVa. Prompted by the finding of four patients within 6 months in the same ward with this unusual MRSA type, an outbreak was suspected. Subsequent MRSA screening in the ward in February 2017 identified three-additional patients and two health care workers (HCWs) with t267/ST97-IVa. WGS linked these 9 isolates to 16 previous isolates in our WGS database and the outbreak thus included 23 patients and two HCWs. Twenty-one patients had a connection to the surgery ward during the period 2013–2017, but half of them had MRSA diagnosed in the community long after discharge. The community debut of several patients MRSA infections weeks to months after hospital discharge made the identification of a hospital source difficult and it was the SNP relatedness of the isolates that led us to identify the common denominator of hospitalization. An index patient was not identified, but our hypothesis is that HCWs with unrecognized long-term MRSA colonization could have caused sporadic nosocomial transmission due to intermittent breaches in infection prevention and control practice.

Social media posts and online search behaviour as early-warning system for MRSA outbreaks

BackgroundDespite many preventive measures, outbreaks with multi-drug resistant micro-organisms (MDROs) still occur. Moreover, current alert systems from healthcare organizations have shortcomings due to delayed or incomplete notifications, which may amplify the spread of MDROs by introducing infected patients into a new healthcare setting and institutions. Additional sources of information about upcoming and current outbreaks, may help to prevent further spread of MDROs.The study objective was to evaluate whether methicillin-resistant Staphylococcus aureus (MRSA) outbreaks could be detected via social media posts or online search behaviour; if so, this might allow earlier detection than the official notifications by healthcare organizations.MethodsWe conducted an exploratory study in which we compared information about MRSA outbreaks in the Netherlands derived from two online sources, Coosto for Social Media, and Google Trends for search behaviour, to the mandatory Dutch outbreak notification system (SO-ZI/AMR). The latter provides information on MDRO outbreaks including the date of the outbreak, micro-organism involved, the region/location, and the type of health care organization.ResultsDuring the research period of 15 months (455 days), 49 notifications of outbreaks were recorded in SO-ZI/AMR. For Coosto, the number of unique potential outbreaks was 37 and for Google Trends 24. The use of social media and online search behaviour missed many of the hospital outbreaks that were reported to SO-ZI/AMR, but detected additional outbreaks in long-term care facilities.ConclusionsDespite several limitations, using information from social media and online search behaviour allows rapid identification of potential MRSA outbreaks, especially in healthcare settings with a low notification compliance. When combined in an automated system with real-time updates, this approach might increase early discovery and subsequent implementation of preventive measures.

Polymerase chain reaction-based open reading frame typing (POT) method analysis for a methicillin-resistant Staphylococcus aureus (MRSA) outbreak through breast-feeding in the neonatal intensive care unit

IntroductionThe route of methicillin-resistant Staphylococcus aureus (MRSA) transmission in the neonatal intensive care unit (NICU) is not clearly explained. We investigate an MRSA outbreak involving five babies in the NICU. The molecular investigation using polymerase chain reaction-based open reading frame typing (POT) method was performed. Presentation of outbreakA MRSA outbreak occurred in a six-bed NICU affecting 5 babies. Within 13 days of the emergence of index case, all five babies including triplets and other two babies were found to colonize MRSA by the active surveillance culture. Environmental surveillance cultures revealed that the preserved breast milk provided by the triplets' mother was the only item in the NICU that was positive for MRSA. The mother had a bite wound on the nipples, and the breast milk was not pasteurized. The POT method revealed that MRSA strains detected from the triplets, the breast milk, and the other baby who was fed the triplets' mother's milk were genetically identical (POT index: 106-247-33). The all strains of MRSA carried Staphylococcal cassette chromosome mec (SCCmec) IV and had good susceptibility for the non-ß-lactam antimicrobial agents, suggesting the strains were community-acquired MRSA. ConclusionsThe mother’s milk contaminated with community-origin MRSA is serving as the reservoir of MRSA and one of the sources of MRSA outbreaks in the NICU. It is important to closely monitor the condition of the mothers of the children in the NICU. Pasteurization of breast milk should be considered when the skin on the nipple is broken.

A Novel In Situ Simulation Intervention Used to Mitigate an Outbreak of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit

To describe the successful implementation of an in situ simulation program to diagnose and correct latent safety threats in a level 4 neonatal intensive care unit (NICU) to mitigate a methicillin-resistant Staphylococcus aureus (MRSA) outbreak. An investigational report describes a simulation intervention that occurred during a 4-month MRSA outbreak in a single-center, 46-bed, newly renovated level 4 NICU. The simulation program was developed for all NICU providers in which they were exposed to a 30-minute in situ human simulation intervention that included education, evaluation, and debriefing to resolve perceived or observed latent safety threats. The primary study outcome was improved hand hygiene compliance and an enhanced estimate of the culture of safety during a 6-month period. A total of 99 healthcare providers including physicians, nurses, respiratory therapists, and environmental service workers completed the course. Before the simulation intervention, there were 18 patients colonized or infected with a single MRSA clone; after the intervention, there were no new episodes of colonization or infection. An in situ, simulation-based intervention can counter threats to patient safety related to workflow and lapses in infection control practices and improve patient outcomes.

Investigation of a Cluster of Sequence Type 22 Methicillin-Resistant Staphylococcus aureus Transmission in a Community Setting.

Whole-genome sequencing (WGS) has typically been used to confirm or refute hospital/ward outbreaks of methicillin-resistant Staphylococcus aureus (MRSA) identified through routine practice. However, appropriately targeted WGS strategies that identify routinely "undetectable" transmission remain the ultimate aim. WGS of MRSA isolates sent to a regional microbiological laboratory was performed as part of a 12-month prospective observational study. Phylogenetic analyses identified a genetically related cluster of E-MRSA15 isolated from patients registered to the same general practice (GP) surgery. This led to an investigation to identify epidemiological links, find additional cases, and determine potential for ongoing transmission. We identified 15 MRSA-positive individuals with 27 highly related MRSA isolates who were linked to the GP surgery, 2 of whom died with MRSA bacteremia. Of the 13 cases that were further investigated, 11 had attended a leg ulcer/podiatry clinic. Cases lacked epidemiological links to hospitals, suggesting that transmission occurred elsewhere. Environmental and staff screening at the GP surgery did not identify an ongoing source of infection. Surveillance in the United Kingdom shows that the proportion of MRSA bacteremias apportioned to hospitals is decreasing, suggesting the need for greater focus on the detection of MRSA outbreaks and transmission in the community. This case study confirms that the typically nosocomial lineage (E-MRSA15) can transmit within community settings. Our study exemplifies the continued importance of WGS in detecting outbreaks, including those which may be missed by routine practice, and suggests that universal WGS of bacteremia isolates may help detect outbreaks in low-surveillance settings.

Corrigendum: Building a genomic framework for prospective MRSA surveillance in the United Kingdom and the Republic of Ireland.

The correct interpretation of microbial sequencing data applied to surveillance and outbreak investigation depends on accessible genomic databases to provide vital genetic context. Our aim was to construct and describe a United Kingdom MRSA database containing over 1000 methicillin-resistant Staphylococcus aureus (MRSA) genomes drawn from England, Northern Ireland, Wales, Scotland, and the Republic of Ireland over a decade. We sequenced 1013 MRSA submitted to the British Society for Antimicrobial Chemotherapy by 46 laboratories between 2001 and 2010. Each isolate was assigned to a regional healthcare referral network in England and was otherwise grouped based on country of origin. Phylogenetic reconstructions were used to contextualize MRSA outbreak investigations and to detect the spread of resistance. The majority of isolates (n = 783, 77%) belonged to CC22, which contains the dominant United Kingdom epidemic clone (EMRSA-15). There was marked geographic structuring of EMRSA-15, consistent with widespread dissemination prior to the sampling decade followed by local diversification. The addition of MRSA genomes from two outbreaks and one pseudo-outbreak demonstrated the certainty with which outbreaks could be confirmed or refuted. We identified local and regional differences in antibiotic resistance profiles, with examples of local expansion, as well as widespread circulation of mobile genetic elements across the bacterial population. We have generated a resource for the future surveillance and outbreak investigation of MRSA in the United Kingdom and Ireland and have shown the value of this during outbreak investigation and tracking of antimicrobial resistance.

Methicillin-resistant Staphylococcus aureus nasal carriage between healthy students of medical and nonmedical universities

Methicillin-resistant Staphylococcus aureus (MRSA) is a challenge for public health, and community-acquired (CA) infections seem to be increasing among people in different areas. A total of 700 healthy student volunteers residing in dormitories of universities in Urmia, Iran, were enrolled in this study. After identification of the isolates, antibiotic susceptibility, presence of mecA and pvl genes, and staphylococcal cassette chromosome mec (SCCmec) typing were evaluated. Nasal screening identified 137 (19.6%) carriers of S aureus, and 18 (13.14%) were MRSA isolates. The antimicrobial susceptibility patterns of isolates revealed high resistance to penicillin (93.4%). All isolates were sensitive to vancomycin. The SCCmec typing showed that most MRSA strains belonged to SCCmec type IV (n = 14; 77.8%). Only 1 (5.56%) MRSA isolates carried the pvl gene. Our findings revealed the relatively high frequency of S aureus nasal carriers and the advent of multidrug resistance among these isolates. Most MRSA isolates were SCCmec type IV; the transfer of such MRSA strains from carriers to other individuals in crowded living conditions such as dormitories can act as a risk factor for outbreak of CA MRSA and is a serious threat for the study groups.

Developing a Checklist to Identify and Manage MRSA Outbreaks in the Neonatal ICU using a Multi-Disciplinary Approach

BackgroundFrom 2001 to 2015, the New York State Department of Health (NYSDOH) received 241 hospital-associated infection reports from neonatal ICUs (NICUs); 72 (29%) were caused by methicillin-resistant Staphylococcus aureus (MRSA) and involved 390 babies at initial report. Given this MRSA burden and variability in outbreak response, a checklist was developed to help NICUs identify and manage MRSA outbreaks. NYSDOH and academic partners conducted a workshop to teach NICU multidisciplinary teams these skills.MethodsThe checklist committee were members of the NYSDOH and academic subspecialists in infectious disease, infection control and neonatology from three medical centers in NYC; all of whom had reported MRSA outbreaks within the past year. The committee met twice monthly for 6 months and developed the checklist as a practical tool for a multidisciplinary care team to implement existing guidelines. A checklist draft was distributed during the NYSDOH’s one-day workshop to Control and Prevent MRSA Outbreaks, attended by 73 individuals from 25 NICUs in the NYC metropolitan region. Attendees provided feedback to modify the checklist.ResultsThe checklist has 10 sections including guidance about developing a case definition and line list; reporting to the NYS DOH; managing census; communicating with local microbiology laboratories, interdisciplinary teams, families, and employee health service; using transmission-based precautions, obtaining surveillance cultures, cohorting infants and staff, and improving environmental cleaning. Implementation strategies are emphasized, e.g., evaluate effectiveness of environmental cleaning and disinfection practices and empower staff to observe and enforce hand hygiene compliance. Practical tips are provided, e.g., assess equipment shared with other units, review clinical cultures for patterns suggestive of acquisition route, take a non-punitive approach with MRSA-positive staff, perform environmental cultures if other strategies fail to stop transmission. ConclusionChecklists facilitate healthcare delivery. This is the first comprehensive checklist designed to reduce MRSA burden in NICUs. Future work will assess the impact of the checklist on reporting and outbreak size and duration.Disclosures All authors: No reported disclosures.

Identifyingconditions for elimination and epidemic potential of methicillin-resistant Staphylococcus aureus in nursing homes.

BackgroundResidents 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.MethodsModel 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.ResultsOur 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.ConclusionsBased 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.

MALDI-TOF MS typing of a nosocomial methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit

Background: The early detection of a methicillin-resistant Staphylococcus aureus (MRSA) outbreak is decisive to control its spread and rapidly initiate adequate infection control measures. Therefore, prompt determination of epidemiologic relatedness of clinical MRSA isolates is essential. Genetic typing methods have a high discriminatory power but their availability remains restricted. In this study, we aimed to challenge matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a typing tool of a nosocomial MRSA outbreak in a neonatal intensive care unit.Methods: Over a 2-year period, 15 MRSA isolates were recovered from patients (n = 14) and health care workers (n = 1) at the neonatal intensive care unit. Five reference strains were included for comparison. Identification was performed by MALDI-TOF MS and susceptibility profiles determined by automated broth microdilution. Typing analysis by MALDI-TOF MS included mean spectrum profiles and subsequent dendrogram creation using BioNumerics software. Results were compared with spa typing and pulsed-field gel electrophoresis (PFGE).Results: Our study showed good concordance (93%) between PFGE, spa typing, and MALDI-TOF MS for the outbreak-related MRSA strains. MALDI-TOF MS typing showed excellent typeability and discriminatory power but showed poor reproducibility.Conclusions: This study is one of the first to document the potential usefulness of MALDI-TOF MS with standardized data analysis as a typing tool for investigating a nosocomial MRSA outbreak. A concordance of 93% compared to reference typing techniques was observed. However, because of poor reproducibility, long-term follow-up of prospective isolated strains is not practical for routine use. Further studies are needed to confirm our observations.

Der Umgang mit MRSA bei Beschäftigten im Gesundheitsdienst aus Sicht der Krankenhaushygiene

Background: Colonisation with methicillin-resistant Staphylococcus aureus (MRSA) is a particular challenge for medical staff and their facilities, with a key role being played by physicians alongside infection control and hospital hygiene professionals. Methods: In 2014, infection control and hygiene staff were surveyed on the handling of hospital staff with MRSA colonisation. The questionnaire queried on MRSA management in hospitals and on the cooperation between hygiene staff and hospital physicians and was compared to a survey of physicians' experience with the care of MRSA-positive hospital staff. Results: 124 hospital hygiene professionals participated in the survey. General screenings of staff members were reported mainly for cases of MRSA outbreak. Temporary colonisation is differentiated from permanent colonisation (47%). 2 unsuccessful attempts at decolonisation are normally regarded as an indicator for a permanent colonisation. Generally there was cooperation between hospital physicians and hygiene staff. The responsibility for screening and decolonisation of staff members is shared by both groups with the groups placing emphasis on different focal points. Different approaches for the handling of MRSA-positive staff were reported and recommendations for the work ability vary from merely observing the standard hygiene regulation to refraining from close patient contact or even complete absence from work. Conclusion: MRSA colonisation in hospital staff is being dealt with in different manners. Infection control and hospital hygiene professionals are equally involved in the treatment. Clear regulations would benefit the handling of MRSA in staff members.