Methicillin-resistant Staphylococcus Aureus Acquisition Research Articles

Are Contact Precautions "Essential" for the Prevention of Healthcare-associated Methicillin-Resistant Staphylococcus aureus?

The recently updated Society for Healthcare Epidemiology of America, the Infectious Diseases Society of America, and the Association of Professionals in Infection Control practice recommendations for methicillin-resistant Staphylococcus aureus (MRSA) prevention in acute care facilities list contact precautions (CPs) for patients known to be infected or colonized with MRSA as an "essential practice," meaning that it should be adopted in all acute care facilities. We argue that existing evidence on benefits and harms associated with CP do not justify this recommendation. There are no controlled trials that support broad use of CP for MRSA prevention. Data from hospitals that have discontinued CP for MRSA have found no impact on MRSA acquisition or infection. The burden and harms of CP remain concerning, including the environmental impact of increased gown and glove use. We suggest that CP be included among other "additional approaches" to MRSA prevention that can be implemented under specific circumstances (eg outbreaks, evidence of ongoing transmission despite application of essential practices).

Analysis of the Trends of Methicillin-Resistant Staphylococcus aureus in Gauteng Public Hospitals from 2009 to 2018.

Most investigations into the distribution of methicillin resistant Staphylococcus aureus (MRSA) have focused exclusively on bloodborne infections within individual health care institutions for shorter time periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. Therefore, in this study we determined the demographic and geographical patterns of MRSA infections and their fluctuation in 10 years within all public hospitals in Gauteng, South Africa. A retrospective analysis of S. aureus samples was done by deduplicating samples in two groups. The sample groups were placed into subsets with respect to demographic and geographical fields and compared across the studied period. Logistic regression was utilized to determine odds ratios for resistant infections in univariate and multivariable configurations. A total of 66,071 unique infectious events were identified from the 148,065 samples received over a 10-year period, out of which 14,356 were identified as bacteremia. MRSA bacteremia rates in Gauteng peaked in 2015 and have since decreased. Within Gauteng, metropolitan areas have the greatest burden of MRSA with children under 5 years of age and males being most affected. Medical wards have the highest S. aureus bacteremia rates, while intensive care units have the highest MRSA bacteremia rates. Patient age, admitting ward, and geographical district are the most important associated factors of resistance. MRSA acquisition rates have shown tremendous growth since 2009 but have since spiked and subsequently decreased. This may be due to the initiation of the National Guidelines on Antimicrobial Stewardship and Infectious Disease Surveillance. Further studies to determine the trajectory of infections are required to support these claims. IMPORTANCE S. aureus is the leading cause of a variety of devastating clinical conditions, including infective endocarditis, bacteremia, and pleuropulmonary infections. It is an important pathogen responsible for substantial morbidity and mortality. MRSA is a variant of interest originally responsible for difficult to treat hospital-acquired infections that has since achieved community spread throughout the world. Most investigations into the distribution of MRSA have focused exclusively on bloodborne infections within individual health care institutions for shorter periods. This has limited the analysis of a community-spread pathogen to snapshots within the hospital domain. This study sought to determine the demographic and geographical patterns of MRSA infections as well as how these have fluctuated over time within all public hospitals. This will also help in understanding the epidemiology and resistance trends of S. aureus, which will help clinicians to understand the clinical prospective and policy makers to design guidelines and strategies for treating such infections.

Modeling methicillin-resistant Staphylococcus aureus (MRSA) acquisitions in the intensive care unit with different staffing levels and finite direct-care tasks

Background: Modeling is a cost-effective way to evaluate interventions pertaining to hospital infection acquisitions, such as staffing levels. Increasing the number of nurses in an intensive care unit affects rates of HAI transmission. The way compartmental models are often formulated assumes that there is a never-ending series of tasks for workers to perform. Our previous models used a baseline of 1:3 nurse:patient ratio, and we kept the number of tasks the same across staffing ratios. We wanted to understand how having a finite number of tasks, using this baseline number, across staffing levels affected HAI acquisitions. Methods: We used a stochastic mathematical model of methicillin-resistant Staphylococcus aureus (MRSA) to study the impact of changes in staffing and a finite pool of tasks on hospital-associated acquisitions. For a 15-bed intensive care unit (ICU), we have 1 intensivist, and we set the nurse:patient ratios at 1:1, 1:1.5, 1:2.5, 1:3, 1:5, and 1:7.5, to represent the extreme ends of staffing levels and more moderate values in line with critical care society guidelines. Each model was run 1,000 times. The outcome of each scenario is the median number of hospital-associated MRSA acquisitions in 1 year from those 1,000 runs. Results: Treating the 1:3 nurse:patient ratio as the baseline, with 45 MRSA acquisitions per year, increasing the number of nurses from 5 to 6 (moving to a 1:2.5 nurse:patient ratio) had a relative risk (RR) of 0.77, suggesting that a small change in nurse staffing levels might have an outsized impact on rates. More dramatic changes had correspondingly larger swings in MRSA acquisition rates, with 1:1 nurse:patient ratio scenarios having an RR of 0.17, and at the other extreme, a 1:7.5 nurse:patient ratio having an RR of 4.66. Comparing the infinite to finite models, the ratios with more nurses had lower acquisition rates, with decreases ranging from 20% to 50%. Ratios with fewer nurses in the ICU showed 100%–400% increases in the number of acquisitions. All results were statistically significant. Conclusions: As nurse:patient ratios go up, the burden of direct-care tasks fall on fewer people, which has a direct impact on HAI rates. Our model demonstrates this hypothesis. Therefore, appropriate staffing should be considered in infection control guidelines, and the cost of staffing should be weighed against its impact on infection prevention as well as other areas of patient care. In this study, we considered only the impact from changes in contact patterns emerging from different staffing levels. Further insights may exist when considering other outcomes that also accompany increased staffing.Disclosures: None

Paradoxical consequences of wastewater interventions targeting carbapenemase-producing Enterobacterales

Background:Serratia marcescens is a leading cause of hospital-acquired infections. There has been increasing recognition of hospital wastewater as a reservoir for carbapenemase-producing Enterobacterales (CPE), including S. marcescens. Because CPE can proliferate in biofilms in sink drains and traps, controlling nosocomial spread is challenging. The ideal approach to eliminate transmission from wastewater to patients remains unknown. Methods: Patients were included if they were admitted to 1 of 2 intensive care units (ICUs) for >12 hours between December 1, 2010, and January 31, 2016. During this period at the University of Virginia Hospital, there was ongoing patient acquisition of multiple species producing Klebsiella pneumoniae carbapenemase (KPC) as well as consistent perirectal KPC surveillance. In January 2014, to eliminate CPE-colonized sinks, the sink drains and traps in one of the ICUs (ie, the “intervention unit”) were exchanged followed by varied chemical mitigations to prevent recolonization. In another ICU, the same chemical mitigations were performed but without plumbing replacement (ie, the “control unit”). Acquisition of KPC-producing S. marcescens was defined as colonization or infection >12 hours after admission to either unit. To control for increases in patient-to-patient transmission, acquisition of methicillin-resistant Staphylococcus aureus (MRSA) was evaluated in the intervention unit during the same period and was defined as new colonization or infection with MRSA >12 hours after unit admission but within 21 days of last unit exposure. Results: For the postintervention period, risk of S. marcescens acquisition was increased (RR, 2.85; 95% CI, 1.24–6.58; P = .01) in the intervention unit compared to the control unit. In the intervention unit, the risk of S. marcescens acquisition increased in the postintervention period compared to the preintervention period (RR, 6.26; 95% CI, 2.59–15.1; P < .0001). There was no change in MRSA acquisition in the intervention unit representing consistent patient-to-patient infection prevention (RR, 0.95; 95% CI, 0.61–1.48; P = .81). S. marcescens isolates were noted to be highly clonal. Conclusions: Exposure to the intervention unit following plumbing replacement was associated with increased relative risk of acquisition of KPC-producing S. marcescens. This increased risk was not observed in the control unit, which had only chemical plumbing interventions. There was no concomitant increase in patient-to-patient MRSA transmission. The disturbance of the wastewater environment through the plumbing replacement intervention may have led to the unintended consequence of more KPC-producing S. marcescens acquisition.Disclosures: None

Evaluation of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia: Epidemiology, clinical characteristics, and outcomes in the older patients in a tertiary teaching hospital in Malaysia

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a major concern in the global healthcare system. However, data from Asian regions dealing with the singularity of this infection in older persons is lacking. We aimed to identify the differences in the clinical characteristics and outcomes of MRSA bacteremia between adults aged 18–64 and ≥ 65 years.MethodsA retrospective study cohort was conducted at the University Malaya Medical Centre (UMMC) on cases of MRSA bacteremia from 2012 to 2016. Patient demographic and clinical data were collected for risk factors analyses.ResultsNew cases of MRSA bacteremia showed a trend of increase from 0.12 to 100 admissions in 2012 to 0.17 per 100 admissions in 2016 but a drop was observed in 2014 (0.07 per 100 admissions). Out of the 275 patients with MRSA bacteremia, 139 (50.5%) patients were aged ≥ 65 years old. Co-morbidities and severity at presentation were significantly higher among older adults, including diabetes mellitus (p = 0.035), hypertension (p = 0.001), and ischemic heart disease (p < 0.001), as well as higher Charlson Comorbidity Index (p < 0.001) and Pitt bacteremia scores (p = 0.016). Central line-associated bloodstream infections were more common among younger patients (37.5% vs. 17.3% in older patients, p < 0.001), while skin and soft tissue infections are more frequent among older adults (20.9% vs. 10.3% in younger patients, p = 0.016). All-cause mortality and in-hospital mortality were significantly higher in older patients (82.7% and 56.1% vs. 63.2% and 28.7% in younger patients, p < 0.001). Multivariate analysis revealed age ≥ 65 years (adjusted odds ratio: 3.36; 95% confidence interval: 1.24–9.13), Pitt score ≥ 3 (2.15; 1.54–3.01), hospital (6.12; 1.81–20.72) and healthcare (3.19; 1.30–7.81) acquisition of MRSA, indwelling urinary catheters (5.43; 1.39–21.23), inappropriate targeted treatment (8.08; 1.15–56.86), lack of infectious disease team consultation (2.90; 1.04–8.11) and hypoalbuminemia (3.31; 1.25–8.79), were significant risk factors for 30-day mortality.ConclusionOlder patients’ risk of mortality from MRSA bacteremia was three times higher than younger patients. Our data will contribute to developing and validating a robust scoring system for risk-stratifying patients to achieve better management and improved clinical outcomes.

SG-APSIC1170: Reduction of hospital-onset MRSA bacteremia with chlorhexidine baths among MRSA-colonized patients

Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a major concern for hospitalized patients in Singapore. Hospital-onset (HO) MRSA bacteremia is monitored at the national level as an indicator of hospital quality. Patients who have colonized with methicillin-resistant Staphylococcus aureus (MRSA) are more likely to develop an MRSA infection in the future. A topical antiseptic solution or cloth called chlorhexidine gluconate (CHG) is effective against several gram-positive and gram-negative bacteria, including MRSA. Methods: The following control measures were present before and throughout the study period: (1) active screening of MRSA upon admission; (2) initiation of contact precaution once MRSA is detected; and (3) emphasis on strict hand hygiene. In January 2021, an intervention was for routine application of CHG bathing as follows: (1) training materials were developed; (2) train-the-trainer sessions were organized; (3) compliance regarding the application of CHG baths was monitored; and (4) the postimplementation process was reviewed. Results: There was no change of hand hygiene rate before and after implementation. In 2020, 17 cases of MRSA bacteremia occurred in the hospital, with an infection incidence of 0.54 per 10,000 patient days. In 2021, there were 10 cases of HO-MRSA bacteremia infection, with an overall rate of was 0.30 per 10,000 patient days. Conclusions: Daily bathing with chlorhexidine reduced the risk of MRSA acquisition and of hospital-acquired bacteremia.

Risk factors for methicillin-resistant Staphylococcus aureus colonization in a level-IV neonatal intensive care unit: a retrospective study.

To identify risk factors associated with methicillin-resistant Staphylococcus aureus (MRSA) colonization in neonatal patients during an MRSA outbreak to minimize future outbreaks. Retrospective case-control study. Level-IV neonatal intensive care unit (NICU) at Copenhagen University Hospital, Rigshospitalet, Denmark. Neonates with either MRSA or methicillin-susceptible Staphylococcus aureus (MSSA). Methicillin-resistant Staphylococcus aureus-positive neonates were matched with those colonized or infected with MSSA in a 1:1 ratio. The control group was selected from clinical samples, whereas MRSA-positive neonates were identified from clinical samples or from screening. A total of 140 characteristics were investigated to identify risk factors associated with MRSA acquisition. The characteristics were categorized into three categories: patient, unit, and microbiological characteristics. Out of 1,102 neonates screened for MRSA, between December 2019 and January 2022, 33 were MRSA positive. They were all colonized with an MRSA outbreak clone (spa type t127) and were included in this study. Four patients (12%) had severe infection. Admission due to respiratory diseases, need for intubation, need for peripheral venous catheters, admission to shared rooms with shared toilets and bath facilities in the aisles, and need for readmission were all correlated with later MRSA colonization (P < 0.05). We identified clinically relevant diseases, procedures, and facilities that predispose patients to potentially life-threatening MRSA infections. A specific MRSA reservoir remains unidentified; however, these findings have contributed to crucial changes in our NICU to reduce the number of MRSA infections and future outbreaks.

Epidemiology and infection control of Methicillin-resistant Staphylococcus aureus in a German tertiary neonatal intensive and intermediate care unit: A retrospective study (2013-2020).

In preterm and term infants who require intermediate or intensive care Methicillin-resistant Staphylococcus aureus (MRSA) infection can lead to significant morbidity. In this study MRSA colonization and infection were assessed in a mixed tertiary neonatal intensive and intermediate care unit in Germany over an 8-year period (2013–2020). We investigated patient-related factors, associated with nosocomial MRSA acquisition, and we discuss our infection control concept for MRSA. Of 3488 patients treated during the study period, 24 were MRSA positive patients, corresponding to 26 patient hospital stays. The incidence was 0.7 MRSA patients per 100 patients. The incidence density was 0.4 MRSA patient hospital stays per 1000 patient days. Twelve patients (50%) acquired MRSA in the hospital. One patient developed a hospital acquired MRSA bloodstream infection 9 days after birth (i.e., 0.03% of all patients on the ward during the study period). A total of 122 patients had to be screened to detect one MRSA positive patient. In a logistic regression model, the use of 3rd generation intravenous cephalosporin (cefotaxim) was associated with nosocomial MRSA acquisition compared with matched control patients who did not acquire MRSA. In sum, the burden of MRSA colonization and infection in the ward was low during the study period. A comprehensive infection control concept that included microbiologic colonization screening, prospective infection surveillance together with isolation and emphasis on basic hygiene measures is essential to handle MRSA in this specialized setting.

Considering the precautionary principle and its application to MRSA and SARS-CoV-2 as emerging novel pathogens of their time.

In the 1980s Contact Precautions were introduced as a precautionary measure to control the emerging threat of antimicrobial resistance in hospitals, particularly methicillin resistant Staphylococcus aureus (MRSA). Today, antimicrobial resistance remains a concerning global public health threat, and a focus for hospital patient safety priorities. In late 2019 a novel respiratory virus described as SARS-CoV-2, was reported. Just as MRSA had prompted control measures developed in the context of limited information and understanding of the pathogen, public health control measures against SARS-CoV-2 were promptly and strictly implemented. Whilst SARS-CoV-2 control measures were successful at containing the virus, numerous detrimental socio-economic and health impacts have led to a rebalancing of harms versus benefits and loosening of restrictions. Conversely, evidence collated over the past 50 years, suggests that Contact Precautions are not superior to well-applied standard infection prevention and control precautions in controlling MRSA acquisition in hospitals. Several harms associated with Contact Precautions, affecting patient safety, financial costs, and organisational culture, are described. However, rebalancing of hospital MRSA control policies has been slow to materialise. This commentary invites infection prevention and control policy makers to reflect and revise policies for the control of MRSA in hospitals so that harms do not outweigh benefits.

Examining the impact of ICU population interaction structure on modeled colonization dynamics of Staphylococcus aureus.

Complex transmission models of healthcare-associated infections provide insight for hospital epidemiology and infection control efforts, but they are difficult to implement and come at high computational costs. Structuring more simplified models to incorporate the heterogeneity of the intensive care unit (ICU) patient-provider interactions, we explore how methicillin-resistant Staphylococcus aureus (MRSA) dynamics and acquisitions may be better represented and approximated. Using a stochastic compartmental model of an 18-bed ICU, we compared the rates of MRSA acquisition across three ICU population interaction structures: a model with nurses and physicians as a single staff type (SST), a model with separate staff types for nurses and physicians (Nurse-MD model), and a Metapopulation model where each nurse was assigned a group of patients. The proportion of time spent with the assigned patient group (γ) within the Metapopulation model was also varied. The SST, Nurse-MD, and Metapopulation models had a mean of 40.6, 32.2 and 19.6 annual MRSA acquisitions respectively. All models were sensitive to the same parameters in the same direction, although the Metapopulation model was less sensitive. The number of acquisitions varied non-linearly by values of γ, with values below 0.40 resembling the Nurse-MD model, while values above that converged toward the Metapopulation structure. Inclusion of complex population interactions within a modeled hospital ICU has considerable impact on model results, with the SST model having more than double the acquisition rate of the more structured metapopulation model. While the direction of parameter sensitivity remained the same, the magnitude of these differences varied, producing different colonization rates across relatively similar populations. The non-linearity of the model's response to differing values of a parameter gamma (γ) suggests simple model approximations are appropriate in only a narrow space of relatively dispersed nursing assignments. Simplifying assumptions around how a hospital population is modeled, especially assuming random mixing, may overestimate infection rates and the impact of interventions. In many, if not most, cases more complex models that represent population mixing with higher granularity are justified.

Prevalence of Methicillin-Resistant Staphylococcus aureus at a Tertiary Teaching Hospital in Malaysia

Methicillin-resistant Staphylococcus aureus (MRSA) is a major nosocomial pathogen that causes severe morbidity, mortality and high medical expenses in many hospitals worldwide. The present study aimed to determine the prevalence of MRSA nosocomial infection, its associated factors, and its antimicrobial susceptibility pattern. This was a retrospective analysis of a database of Multidrug- Resistant Organism (MDRO) that was cultured from patients admitted to Hospital Canselor Tuanku Mukhriz (HCTM) over a period of 2 years (2018-2019). MRSA accounted for 23.6% of total MDRO isolates. The male gender had a higher risk for MRSA acquisition (p&lt;0.05), while the most prevalent setting for MRSA was the orthopaedic ward (47.5%) followed by the medical ward (29.4%). The MRSA strains were significantly isolated from respiratory specimens (55.6%) followed by tissue (50.8%) and blood (27.8%). All MRSA isolates were resistant to penicillin G, oxacillin followed by ciprofloxacin (83.8%) erythromycin (71.5%) and clindamycin (53.5%). MRSA isolates were most susceptible to teicoplanin (99.7%), mupirocin (99.3%), co-trimoxazole (98.4%), rifampicin (97.8%), doxycycline (97.4%), linezolid (95.8%), gentamicin (93.9%) and fusidic acid (86.2%). The trend for MRSA’s antibiotic susceptibility in HCTM for the past 2 years (2018 to 2019) remains unchanged. Further research will be required to investigate the predictor of MRSA by clearly differentiating between MRSA infections and colonisations, hospitalacquired MRSA and community-acquired MRSA.

Clinical findings of methicillin-resistant Staphylococcus aureus in cystic fibrosis.

Methicillin-resistant Staphylococcus aureus (MRSA) rates have increased in cystic fibrosis (CF) patients.This study aimed to determine the rate of MRSA, define risk factors, and clarify the effect of MRSA on pulmonary functions, annual pulmonary exacerbation (aPEx) in children with MRSA positive CF. This was a retrospective case control study. CF patients who had ≥1 MRSA (+) respiratory culture between September 2016-2019 were included. MRSA growth rate, colonization status, clinical characteristics, hospitalization rates, FEV1 %predicted, and z-score one year prior to the MRSA isolation, at MRSA growth and one year after MRSA growth were recorded. The aPEx rate changes before-after MRSA growth were evaluated. Sixty-one subjects who had ≥1MRSA growth and 66 controls were enrolled. There was no statistically significant difference between the spirometry indices at first, and 12th month after MRSA acquisition. The mean aPEx was 0.6 one year prior to MRSA acquisition and this rate significantly increased to 1.2 one year after MRSA growth(p &lt; 0.05). The mean hospitalization rate before and after one year of MRSA acquisition significantly increased from 0.17(±0.12) to 0.48 (±0.3)(p:0.008) admissions per year. MRSA growth was related to increased aPEx. Increased aPEx and hospitalization rates after MRSA acquisition suggest MRSA should be eradicated when detected.

173. Deciphering COVID-19-Associated Effects on Hospital MRSA Transmission and Social Networks

173. Deciphering COVID-19-Associated Effects on Hospital MRSA Transmission and Social Networks

Methicillin-resistant Staphylococcus aureus colonization among healthcare workers in Oman.

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. 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. 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. 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.

Community-Associated Methicillin-Resistant Staphylococcus Aureus Colonization in a Birth Cohort of Early Childhood: The Role of Maternal Carriage.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) colonization in infants may pose a risk for subsequent infection in children. The study aimed to determine S. aureus colonization patterns in infancy, and strain relatedness between maternal and infant colonization.Methods: A prospective cohort study was conducted for nasopharyngeal S. aureus detection in neonates at delivery; in children at 1, 6, 12, 24, 36, and 60 months of age; and from mothers immediately after the delivery of their baby and when their child is 1 month old. A questionnaire for infants and mothers was administered at each planned visit.Results: In total, 521 and 135 infant–mother dyads underwent nasopharyngeal swab collection at 1 month and immediately after delivery, respectively. Among the 521 dyads at 1 month of age, concordant S. aureus colonization was found in 95 dyads, including MRSA in 48.4% (46/95). No concordant MRSA carriage was present among the 135 dyads at delivery. The genetic relatedness of concurrent MRSA-colonized dyads showed that more than two-thirds (32/46 [69.6%]) had identical genotypes, mainly ST 59/PVL-negative/SCCmec IV. Infants aged 1 month had the highest incidence of S. aureus, and the trend declined to a nadir at the age of 12 months. Carrier mothers who smoked cigarettes may increase the risk of infant Staphylococcus colonization (odds ratio, 2.12; 95% confidence interval, 1.23–3.66; p < 0.01).Conclusions: Maternal–infant horizontal transmission may be the primary source of MRSA acquisition in early infancy. The avoidance of passive smoking could be recommended for the prevention of S. aureus carriage.

Continuous medical education activities; Answers to Case No. 5: Infection control for MRSA transmission

Methicillin-resistant Staphylococcus aureus (MRSA) is still recognized as one of the most important nosocomial pathogens. These isolates are usually resistant to all currently available β-lactam antibiotics (penicillins, cephalosporins and carbapenems). Vancomycin has historically been the drug of choice and sometimes the last resort for the treatment of serious MRSA infections, providing empirical coverage and definitive therapy. However, its increased use has now become questionable. Moreover, its increased use has already led to emergence of vancomycin-intermediate S. aureus (VISA) as well as vancomycin-resistant S. aureus (VRSA) in certain parts of the world. In the early 1990s, MRSA was reported to account for 20 – 25 % of S. aureus isolates in hospitalized, worldwide. By the middle of the current decade, many hospitals experienced MRSA percentages in the range of 50-70% of total S. aureus isolates from clinical cultures. Recent studies have found that an increasing proportion of hospital-onset invasive MRSA infections are caused by community strains. The clinical scenario has been more dramatic by MRSA colonization which increases the risk of infection, and infecting strains match colonizing strains in as many as 50–80% of cases. Methicillin-resistant Staphylococcus aureus may persist within the hospital environment for a long time, complicating attempts of eradication. Besides, colonization is not static, as strains have been found to evolve and even to be replaced within the same host. Poor infection control measures as well as continues and indiscriminate use of antibiotics have resulted in this huge problem of acquisition and dissemination of MRSA.

Ward-level factors associated with methicillin-resistant Staphylococcus aureus acquisition-an electronic medical records study in Singapore.

Methicillin-Resistant Staphylococcus aureus (MRSA) is endemic in hospitals worldwide. Intrahospital transfers may impact MRSA acquisition risk experienced by patients. In this study, we investigated ward characteristics and connectivity that are associated with MRSA acquisition. We analysed electronic medical records on patient transfers and MRSA screening of in-patients at an acute-care tertiary hospital in Singapore to investigate whether ward characteristics and connectivity within a network of in-patient wards were associated with MRSA acquisition rates over a period of four years. Most patient transfers concentrated in a stable core network of wards. Factors associated with increased rate of MRSA acquisition were MRSA prevalence among patients transferred from other wards (rate ratio (RR): 7.74 [95% confidence interval (CI): 3.88, 15.44], additional 5 percentage point), critical care ward (RR: 1.72 [95% CI: 1.09, 2.70]) and presence of MRSA cohorting beds (RR: 1.39 [95% CI: 1.03, 1.90]. Oncology ward (RR: 0.66 [95% CI: 0.46, 0.94]) (compared to medical ward), and median length of stay (RR: 0.70 [95% CI: 0.55, 0.90], additional 1.5 days) were associated with lower acquisition rates. In addition, we found evidence of interaction between MRSA prevalence among patients transferred from other wards and weighted in-degree although the latter was not associated with MRSA acquisition after controlling for confounders. Wards with higher MRSA prevalence among patients transferred from other wards were more likely to have higher MRSA acquisition rate. Its effect further increased in wards receiving greater number of patients. In addition, critical care ward, presence of MRSA cohorting beds, ward specialty, and median length of stay were associated with MRSA acquisition.

Intranasal octenidine for methicillin-resistant Staphylococcus aureus (MRSA) carriers and universal octenidine bathing reduced MRSA acquisition in an acute-care general ward.

In this quasi-experimental before-and-after study in a methicillin-resistant staphylococcus aureus (MRSA) high-prevalence acute-care dermatology ward from August 2016 to November 2018, patients admitted during intervention period who received additional topical intranasal octenidine were 63% less likely to acquire MRSA than those receiving universal daily octenidine bathing alone during baseline period (aOR, 0.37; 95% CI, 0.14-0.98).

Methicillin-Resistant Staphylococcus Aureus Bacteremia: Epidemiology, Clinical Characteristics, Risk Factors, and Outcomes in a Tertiary Care Center in Riyadh, Saudi Arabia.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) has become increasingly common in hospitals worldwide. In an era of pandemics, it is important to understand all types of infectious diseases in order to control its outcome and reduce mortality rates related to it. This study aims to identify the epidemiology of MRSA bloodstream infection, risk factors, and mortality in King Abdulaziz Medical City in Riyadh.MethodsThis is a retrospective chart review study from January 2013 to June 2017. All patients with positive blood culture for MRSA at King Abdulaziz Medical City (KAMC), which is a tertiary care center in Riyadh, Saudi Arabia, were included. Data were extracted from electronic and paper medical records for patients who had a positive blood culture for MRSA. Data collected included demographics, microbiological details, risk factors, and 30-day mortality.ResultsFrom 2013 through June 2017, 633 Staphylococcus aureus bacteremia were reported in KAMC, of which 184 (29.1%) were MRSA with a mean age of 60±19 years. Almost all of our isolates were susceptible to vancomycin, linezolid, and tigecycline. The most common infectious syndrome these patients presented with was an endovascular infection which accounts for 30.4% while 19.9% presented as a case of pneumonia. The mortality within 30 days of collection of the positive blood culture was 20.65%. Male gender (OR = 2.33; 95% CI = 1.34-4.05; P-value = 0.003) and patients with history of recent hospital (OR = 2.34; 95% CI = 1.27-4.34; P-value = 0.007) or ICU (OR = 1.66; 95% CI = 1.09-2.52; P-value = 0.018) admissions were more likely to acquire MRSA.ConclusionsThe incidence of MRSA bacteremia at King Abdulaziz Medical City is high and increasing in conjunction with incidence rate posing a significantly high rate of mortality. Recent history of hospital admission, ICU admission and males were found to be significantly associated with higher rates of MRSA infection. Some modifiable risk factors that could be used to facilitate the reduction of MRSA acquisition rates is to avoid unnecessary hospital and ICU admissions.

Combining pulsed xenon ultraviolet disinfection with terminal manual cleaning helps reduce the acquisition rate of methicillin-resistant Staphylococcus aureus

The clinical effectiveness of ultraviolet light (UV) disinfection remains unclear. This study aimed to investigate the effect of adding pulsed xenon UV (PX-UV) disinfection to the terminal cleaning protocol on the rate of methicillin-resistant Staphylococcus aureus (MRSA) acquisition at a Japanese hospital. The use of a PX-UV disinfection device was added to the manual terminal cleaning protocol applied after the discharge or transfer of patients treated in the intensive and high care units. We used a Poisson regression model to examine the incidence of MRSA acquisition, based on the study period, PX-UV intervention status, unit type, and the rate of consumption of alcohol-based hand rub (ABHR). Approximately 86% of the rooms in the intervention units were terminally disinfected with the PX-UV device. In the intervention units, the incidence of MRSA acquisition decreased from 3.56 per 1,000 patient-days in the nonintervention period to 2.21 per 1,000 patient-days in the intervention period. Moreover, the use of PX-UV disinfection decreased the risk of MRSA acquisition (incident rate ratio: 0.556; 95% confidence interval, 0.309-0.999; P = .0497). ABHR consumption did not affect the risk of MRSA acquisition. Adding PX-UV disinfection to terminal manual cleaning reduced the rate of MRSA acquisition.