Cost-effectiveness of a real-time spatiotemporal mapping surveillance system for meticillin-resistant Staphylococcus aureus prevention.

OBJECTIVES: An infection surveillance system based on a hospital's digital twin [4D-Disease Outbreak Surveillance System (4D-DOSS)] is being developed in Singapore. It offers near-real-time infection surveillance and mapping capabilities. This early economic modelling study was conducted, using meticillin-resistant Staphylococcus aureus (MRSA) as the pathogen of interest, to assess the potential cost-effectiveness of 4D-DOSS. METHODS: A Markov model that simulates the likelihood of MRSA colonization and infection was developed to evaluate the cost-effectiveness of adopting 4D-DOSS for MRSA surveillance from the hospital perspective, compared with current practice. The cycle duration was 1 day, and the model horizon was 30 days. Probabilistic sensitivity analysis was conducted, and the probability of cost-effectiveness was reported. Scenario analyses and a value of information analysis were performed. RESULTS: In the base-case scenario, with 10-year implementation/maintenance costs of 4D-DOSS of $0, there was 68.6% chance that 4D-DOSS would be cost-effective. In a more pessimistic but plausible scenario where the effectiveness of 4D-DOSS in reducing MRSA transmission was one-quarter of the base-case scenario with 10-year implementation/maintenance costs of $1 million, there was 47.7% chance that adoption of 4D-DOSS would be cost-effective. The value of information analysis showed that uncertainty in MRSA costs made the greatest contribution to model uncertainty. CONCLUSIONS: This early-stage modelling study revealed the circumstances for which 4D-DOSS is likely to be cost-effective at the current willingness-to-pay threshold, and identified the parameters for which further research will be worthwhile to reduce model uncertainty. Inclusion of other drug-resistant organisms will provide a more thorough assessment of the cost-effectiveness of 4D-DOSS.

Green Synthesized Iron-Coated Silver Nanoparticles: Economic Bimetallic Nanoparticles Potential Against Methicillin-Resistance Staphylococcus aureus.

Iron coating was introduced as one of the novel techniques to improve physicochemical and biological properties of silver nanoparticles (AgNPs). In the current experiment, impact of iron coating on the antimicrobial potency of AgNPs was investigated against methicillin-resistance Staphylococcus aureus (MRSA). To obtain more accurate data about the antimicrobial potency of examined nanostructures, the experiment was done on the 10 isolates of MRSA which were isolated from skin lesions. AgNPs and iron-coated AgNPs (Fe@AgNPs) were fabricated based on a green one-pot reaction procedure. Minimal inhibitory concentration (MIC) of Fe@AgNPs was not significantly different with MIC of AgNPs against eight out of 10 examined MRSA isolates. Also, by iron coating a reduction in the minimal inhibitory concentration (MIC) of AgNPs was observed against two MRSA isolates. The average MIC of AgNPs against 10 MRSA isolates was calculated to be 2.16 ± 0.382 mg/mL and this value was reduced to 1.70 ± 0.638 mg/mL for Fe@AgNPs. However, this difference was not considered significant statistically (P-value > 0.05). From productivity point of view, it was found that iron coating would improve the productivity of the synthesis reaction more than fivefold. Productivity of AgNPs was calculated to be 1.02 ± 0.07 g/L, meanwhile this value was 5.25 ± 0.05 g/L for Fe@AgNPs. Iron coating may provide another economic benefit to reduce final price of AgNPs. It is obvious that the price of a particular nanostructure made of silver and iron is significantly lower than that of pure silver. These findings can be considered for the fabrication of economic and potent antimicrobial nanoparticles.

Pre-surgical Nasal Decolonization of Staphylococcus aureus: A Health Technology Assessment.

Background: Staphylococcus aureus (S. aureus) is the most common cause of surgical site infections, and the nose is the most common site for S. aureus colonization. Pre-surgical (in the days prior to surgery) nasal decolonization of S. aureus may reduce the bacterial load and prevent the organisms from being transferred to the surgical site, thus reducing the risk of surgical site infection. We conducted a health technology assessment of nasal decolonization of S. aureus (including methicillin-susceptible and methicillin-resistant strains) with or without topical antiseptic body wash to prevent surgical site infection in patients undergoing scheduled surgery, which included an evaluation of effectiveness, safety, cost-effectiveness, the budget impact of publicly funding nasal decolonization of S. aureus, and patient preferences and values. Methods: We performed a systematic literature search of the clinical evidence to retrieve systematic reviews and selected and reported results from one review that was recent, of high quality, and relevant to our research question. We complemented the chosen systematic review with a literature search to identify randomized controlled trials published since the systematic review was published in 2019. We used the Risk of Bias in Systematic Reviews (ROBIS) tool to assess the risk of bias of each included systematic review and the Cochrane risk-of-bias tool for randomized controlled trials to assess the risk of bias of each included primary study. We assessed the quality of the body of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) Working Group criteria. We performed a systematic economic literature search and conducted both cost-effectiveness and cost-utility analyses using a decision-tree model with a 1-year time horizon from the perspective of Ontario's Ministry of Health. We also analyzed the budget impact of publicly funding nasal decolonization of S. aureus in pre-surgical patients in Ontario. To contextualize the potential value of nasal decolonization, we spoke with people who had recently undergone surgery, some of whom had received nasal decolonization, and one family member of a person who had recently had surgery. We also engaged participants through an online survey. Results: We included one systematic review and three randomized controlled trials in the clinical evidence review. In universal decolonization, compared with placebo or no intervention, nasal mupirocin alone may result in little to no difference in the incidence of overall and S. aureus-related surgical site infections in pre-surgical patients undergoing orthopaedic, cardiothoracic, general, oncologic, gynaecologic, neurologic, or abdominal digestive surgeries, regardless of S. aureus carrier status (GRADE: Moderate to Very low). Compared with placebo, nasal mupirocin alone may result in little to no difference in the incidence of overall and S. aureus-related surgical site infections in pre-surgical patients who are S. aureus carriers undergoing cardiothoracic, vascular, orthopaedic, gastrointestinal, general, oncologic, gynaecologic, or neurologic surgery (GRADE: Moderate to Very low). In targeted decolonization, compared with placebo, nasal mupirocin combined with chlorhexidine body wash lowers the incidence of S. aureus-related surgical site infection (risk ratio: 0.32 [95% confidence interval: 0.16-0.62]) in pre-surgical patients who are S. aureus carriers undergoing cardiothoracic, vascular, orthopaedic, gastrointestinal, or general surgery (GRADE: High). Compared with no intervention, nasal mupirocin combined with chlorhexidine body wash in pre-surgical patients who are not S. aureus carriers undergoing orthopaedic surgery may have little to no effect on overall surgical site infection, but the evidence is very uncertain (GRADE: Very low). Most included studies did not separate methicillin-susceptible and methicillin-resistant strains of S. aureus. No significant antimicrobial resistance was identified in the evidence reviewed; however, the existing literature was not adequately powered and did not have sufficient follow-up time to evaluate antimicrobial resistance.Our economic evaluation found that universal nasal decolonization using mupirocin combined with chlorhexidine body wash is less costly and more effective than both targeted and no nasal decolonization. Compared with no nasal decolonization treatment, universal and targeted nasal decolonization using mupirocin combined with chlorhexidine body wash would prevent 32 and 22 S. aureus-related surgical site infections, respectively, per 10,000 patients. Universal nasal decolonization would lead to cost savings, whereas targeted nasal decolonization would increase the overall cost for the health care system since patients must first be screened for S. aureus carrier status before receiving nasal decolonization with mupirocin. The annual budget impact of publicly funding universal nasal decolonization in Ontario over the next 5 years ranges from a savings of $2.98 million in year 1 to a savings of $15.09 million in year 5. The annual budget impact of publicly funding targeted nasal decolonization ranges from an additional cost of $0.08 million in year 1 to an additional cost of $0.39 million in year 5.Our interview and survey respondents felt strongly about the value of preventing surgical site infections, and most favoured a universal approach. Conclusions: Based on the best evidence available, decolonization of S. aureus using nasal mupirocin combined with chlorhexidine body wash prior to cardiothoracic, vascular, orthopaedic, gastrointestinal, or general surgery lowers the incidence of surgical site infection caused by S. aureus in patients who are S. aureus carriers (including methicillin-susceptible and methicillin-resistant strains) (i.e., targeted decolonization). However, nasal mupirocin alone may result in little to no difference in overall surgical site infections and S. aureus-related surgical site infections in pre-surgical patients prior to orthopaedic, cardiothoracic, general, oncologic, gynaecologic, neurologic, or abdominal digestive surgeries, regardless of their S. aureus carrier status (i.e., universal decolonization). No significant antimicrobial resistance was identified in the evidence reviewed.Compared with no nasal decolonization treatment, universal nasal decolonization with mupirocin combined with chlorhexidine body wash may reduce S. aureus-related surgical site infections and lead to cost savings. Targeted nasal decolonization with mupirocin combined with chlorhexidine body wash may also reduce S. aureus-related surgical site infections but increase the overall cost of treatment for the health care system. We estimate that publicly funding universal nasal decolonization using mupirocin combined with chlorhexidine body wash would result in a total cost savings of $45.08 million over the next 5 years, whereas publicly funding targeted nasal decolonization using mupirocin combined with chlorhexidine body wash would incur an additional cost of $1.17 million over the next 5 years.People undergoing surgery value treatments aimed at preventing surgical site infections.

Length of stay, hospitalisation costs and in-hospital mortality of methicillin-susceptible and methicillin-resistant Staphylococcus aureus bacteremia in Japan.

OBJECTIVES: To examine the length of stay, hospitalisation costs and case fatality of methicillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA) bacteremia in Japan. STUDY DESIGN: Retrospective cohort study. Patients with a diagnosis of S. aureus bacteremia who were admitted to a tertiary care hospital (the National Centre for Global Health and Medicine [NCGM]) in Tokyo, Japan, between 1st January 2016 and 31st December 2020 were included in the study. METHODS: We combined Japan Nosocomial Infections Surveillance data and Diagnosis Procedure Combination data at NCGM from 2016 to 2020. The data were stratified into MSSA and MRSA groups. Length of stay (LoS), LoS after submission of a blood culture specimen (LoS-after), hospitalisation cost, hospitalisation costs per day and clinical outcome were compared after propensity score matching. RESULTS: Median LoS was 46 (interquartile range [IQR] 28.5-64.5) days in the MSSA group and 66 (IQR 40-91) days in the MRSA group (P = 0.020). Median LoS-after was 38 (IQR 25-62.5) days and 45 (IQR 24-63) days (P = 0.691) in the MSSA and MRSA groups, respectively. Median hospitalisation cost was significantly higher in the MRSA group (26,035 [IQR 18,154-47,362] USD) than in the MSSA group (19,823 [IQR 13,764-32,042] USD) (P = 0.036), but cost per day was not (MRSA: 528.9 [IQR 374.9-647.4] USD; MSSA: 455.6 [IQR 359.2-701.7] USD; P = 0.990). Case fatality rate was higher in the MRSA group than in the MSSA group (22/60 vs 9/60, P = 0.012). CONCLUSIONS: Patients with MRSA bacteremia had longer LoS and higher costs than those with MSSA bacteremia. However, LoS-after and hospitalisation costs per day were not different. The longer LoS of patients in Japan compared with other countries might contribute to the higher disease burden of S. aureus bacteremia in Japan.

Comparison of an Automated Plate Assessment System (APAS Independence) and Artificial Intelligence (AI) to Manual Plate Reading of Methicillin-Resistant and Methicillin-Susceptible Staphylococcus aureus CHROMagar Surveillance Cultures.

The automated plate assessment system (APAS Independence; Clever Culture System, Bäch, Switzerland) is an automated imaging station linked with interpretive software that detects target colonies of interest on chromogenic media and sorts samples as negative or presumptive positive. We evaluated the accuracy of the APAS to triage methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus cultures using chromogenic medium compared to that by human interpretation. Patient samples collected from the nares on ESwabs were plated onto BD BBL CHROMagar MRSA II and BD BBL CHROMagar Staph aureus and allowed to incubate for 20 to 24 h at 37°C in a non-CO2 incubator. Mauve colonies are suggestive of S. aureus and were confirmed with latex agglutination. Following incubation, samples were first interrogated by APAS before being read by a trained technologist blinded to the APAS interpretation. The triaging by both APAS and the technologists was compared for accuracy. Any discordant results required further analysis by a third reader. Over a 5-month period, 5,913 CHROMagar MRSA cultures were evaluated. Of those, 236 were read as concordantly positive, 5,525 were read as concordantly negative, and 152 required discordant analysis. Positive and negative percent agreements (PPA and NPA, respectively) were 100% and 97.3%, respectively. The APAS detected 5 positive cultures that were missed by manual reading and determined to be true positives. In a separate analysis, 744 CHROMagar Staph aureus plates were read in parallel. Of these, 133 were concordantly positive, 585 were concordantly negative, and 26 required discordant analysis. PPA and NPA were 95.7% and 96.7%, respectively. This study confirmed the high sensitivity of digital image analysis by the APAS Independence such that negative cultures can be reliably reported without technologist intervention (negative predictive values [NPVs] of 100% for CHROMagar MRSA and 99.0% for CHROMagar Staph aureus). Triaging using the APAS Independence may provide great efficiency in a laboratory with high throughput of MRSA and S. aureus surveillance cultures.

Can the Xpert MRSA/SA BC assay be used as an antimicrobial stewardship tool? A prospective assay validation and descriptive impact assessment study in a South African setting.

BACKGROUND: Positive blood cultures showing Gram positive cocci in clusters signifies either Staphylococcus aureus or the less-virulent coagulase-negative staphylococci. Rapid identification and methicillin susceptibility determination with the Xpert MRSA/SA BC assay can improve management of S. aureus bloodstream infection and reduce inappropriate antibiotic use. METHODS: We prospectively evaluated the Xpert MRSA/SA BC assay in comparison with culture, on samples referred to our laboratory in the Western Cape, South Africa. We interviewed attending clinicians upon culture result availability, to assess antibiotic choices and estimate potential impact of the assay. RESULTS: Of the 231 samples included, there was 100% concordance between the Xpert MRSA/SA BC assay and culture (methicillin-resistant S. aureus 15/15, methicillin-susceptible S. aureus 42/42, coagulase-negative staphylococci 170/170). Time to final result could be reduced by approximately 30 h with the assay. Of the 178 patients with adequate antibiotic history, optimisation of antistaphylococcal therapy could have occurred more than 1 day sooner in 68.9% with S. aureus bloodstream infection (31/45, 95% CI 53.2-81.4%). Six of the 11 patients with methicillin-resistant S. aureus bloodstream infection (54.5%) could have received anti-MRSA cover sooner. Fifty-four days of antibiotic therapy could have been spared, equating to 0.3 days (95% CI, 0.2-0.4) saved per patient, driven by broad-spectrum beta-lactams (32 days, in 18.0% of the cohort). CONCLUSION: This assay has potential as an antimicrobial stewardship tool; costing and impact on clinical outcome in patients with S. aureus bloodstream infection should be assessed.

Comparing methods to estimate incremental inpatient costs and length of stay due to methicillin-resistant Staphylococcus aureus in Alberta, Canada.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic bacterial organism resistant to first line antibiotics. Acquisition of MRSA is often classified as either healthcare-associated or community-acquired. It has been shown that both healthcare-associated and community-acquired infections contribute to the spread of MRSA within healthcare facilities. The objective of this study was to estimate the incremental inpatient cost and length of stay for individuals colonized or infected with MRSA. Common analytical methods were compared to ensure the quality of the estimate generated. This study was performed at Alberta Ministry of Health (Edmonton, Alberta), with access to clinical MRSA data collected at two Edmonton hospitals, and ministerial administrative data holdings. METHODS: A retrospective cohort study of patients with MRSA was identified using a provincial infection prevention and control database. A coarsened exact matching algorithm, and two regression models (semilogarithmic ordinary least squares model and log linked generalized linear model) were evaluated. A MRSA-free cohort from the same facilities and care units was identified for the matched method; all records were used for the regression models. Records span from January 1, 2011 to December 31, 2015, for individuals 18 or older at discharge. RESULTS: Of the models evaluated, the generalized linear model was found to perform the best. Based on this model, the incremental inpatient costs associated with hospital-acquired cases were the most costly at $31,686 (14,169 - 60,158) and $47,016 (23,125 - 86,332) for colonization and infection, respectively. Community-acquired MRSA cases also represent a significant burden, with incremental inpatient costs of $7397 (2924 - 13,180) and $14,847 (8445 - 23,207) for colonization and infection, respectively. All costs are adjusted to 2016 Canadian dollars. Incremental length of stay followed a similar pattern, where hospital-acquired infections had the longest incremental stays of 35.2 (16.3-69.5) days and community-acquired colonization had the shortest incremental stays of 3.0 (0.6-6.3) days. CONCLUSIONS: MRSA, and in particular, hospital-acquired MRSA, places a significant but preventable cost burden on the Alberta healthcare system. Estimates of cost and length of stay varied by the method of analysis and source of infection, highlighting the importance of selecting the most appropriate method.

Assessment of current methicillin-resistant Staphylococcus aureus screening protocols and outcomes at an academic medical center.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for many hospital-associated infections. Both MRSA-colonized and MRSA-infected patients must be isolated on contact precautions per the Centers for Disease Control and Prevention guidelines. This study evaluates the current practice for removing MRSA-colonized patients from contact precautions and proposes a new protocol to decrease inconsistencies with screening methodologies. METHODS: This was a retrospective chart review of MRSA screening swabs collected at an academic medical center between January 1, 2010 and December 31, 2017. Of those patients with MRSA screening swabs, extra-nasal cultures were also evaluated for MRSA infection. Screening swabs were analyzed for appropriateness of order and timing between swabs and active infections. Analysis of variance and the χ² tests were used to determine significance between groups. RESULTS: This study included 8,310 patients with a combined total of 11,601 nasal swabs. Significantly more (P = .0159) patients with 2 negative nasal swabs returned with a recurrent MRSA infection or colonization than those who had 3 consecutive negative nasal swabs (27.8% vs 17.0%, respectively). Additionally, 47.8% of patients only had 1 appropriately ordered negative nasal swab, indicating that a nurse-driven protocol may be more effective in obtaining the full series of samples required to remove contact precautions. CONCLUSIONS: The current practice for removing a patient from contact precautions for MRSA is insufficient. The number of negative nasal swabs required should be increased from 2 to 3 and a decolonization protocol should be implemented.

Methicillin-susceptible and Methicillin-resistant Staphylococcus aureus Bacteremia: Nationwide Estimates of 30-Day Readmission, In-hospital Mortality, Length of Stay, and Cost in the United States.

BACKGROUND: Information on outcomes of methicillin-susceptible and -resistant Staphylococcus aureus (MSSA and MRSA, respectively) bacteremia, particularly readmission, is scarce and requires further research to inform optimal patient care. METHODS: We performed a retrospective analysis using the 2014 Nationwide Readmissions Database, capturing 49.3% of US hospitalizations. We identified MSSA and MRSA bacteremia using International Classification of Diseases, Ninth Revision, Clinical Modification among patients aged ≥18 years. Thirty-day readmission, mortality, length of stay, and costs were assessed using Cox proportional hazards regression, logistic regression, Poisson regression, and generalized linear model with gamma distribution and log link, respectively. RESULTS: Of 92 089 (standard error [SE], 1905) patients with S. aureus bacteremia, 48.5% (SE, 0.4%) had MRSA bacteremia. Thirty-day readmission rate was 22% (SE, 0.3) overall with no difference between MRSA and MSSA, but MRSA bacteremia had more readmission for bacteremia recurrence (hazard ratio, 1.17 [95% confidence interval {CI}, 1.02-1.34]), higher in-hospital mortality (odds ratio, 1.15 [95% CI, 1.07-1.23]), and longer hospitalization (incidence rate ratio, 1.09 [95% CI, 1.06-1.11]). Readmission with bacteremia recurrence was particularly more common among patients with endocarditis, immunocompromising comorbidities, and drug abuse. The cost of readmission was $12 425 (SE, $174) per case overall, and $19 186 (SE, $623) in those with bacteremia recurrence. CONCLUSIONS: Thirty-day readmission after S. aureus bacteremia is common and costly. MRSA bacteremia is associated with readmission for bacteremia recurrence, increased mortality, and longer hospitalization. Efforts should continue to optimize patient care, particularly for those with risk factors, to decrease readmission and associated morbidity and mortality in patients with S. aureus bacteremia.

Comparación de métodos fenotípico y genotípico en la detección de Staphylococcus aureus meticilino resistente en centros hospitalarios de Pereira / Comparison between phenotype and genotype methods in the detection of Methicillin-Resistant Staphylococcus aureus in Center Hospital of Pereira

Resumen Introducción: Staphylococcus aureus es un importante patógeno, puede causar infecciones leves de piel, hasta enfermedades con compromiso vital. La aparición de Staphylococcus aureus meticilino-resistentes, MRSA; ha aumentado su resistencia antimicrobiana, especialmente a β-lactámicos; dificultando el manejo de las infecciones, aumentando las tasas de morbi-mortalidad, convirtiéndose en un problema de salud pública. La expresión fenotípica de la resistencia suele ser heterogénea, dificultando su detección en el laboratorio por métodos convencionales; lo cual, incrementa los costos en la atención hospitalaria de infecciones por MRSA. Objetivo: Comparar métodos fenotípico y genotípico para la identificación de aislamientos hospitalarios de MRSA en centros hospitalarios de Pereira. Métodos: A partir de aislamientos de S. aureus obtenidos de tres instituciones de salud de alta complejidad clasificadas como A, B y C; se determinó la resistencia a meticilina por concentración mínima inhibitoria en sistemas automatizados y el gen mecA por PCR múltiple. Resultados: La prevalencia fenotípica de MRSA fue 44,4%, la institución A presentó la mayor tasa con 48,65%. La prevalencia genotípica fue 57,4%; en las instituciones A, B y C fue 55,2%, 41,7% y 75%, respectivamente, con diferencia estadísticamente significativa (p<0.05). La sensibilidad y especificidad del método fenotípico fue 99,0% y 94,7%, respectivamente, frente al método gold estándar de la PCR. El índice Kappa fue 0,942 indicando un nivel de concordancia muy bueno entre métodos. Conclusión: La prevalencia de aislamientos MRSA en las instituciones de Pereira fue alta. Los índices de concordancia de los métodos fenotípicos demostraron que son confiables para el diagnóstico de infecciones por MRSA.

Abstract Introduction: Staphylococcus aureus is an important pathogen, can cause mild skin infections, to diseases with compromise vital. The appearance of Methicillin-Resistant Staphylococcus aureus MRSA; It has increased its antimicrobial resistance, especially to β-lactam; hampering the handling of them infections, increasing the rates of morbidity-mortality, becoming a health public problem. The phenotype expression of the resistance tend to be heterogeneous, hindering its detection in the laboratory by conventional methods; which increases costs in the hospital care of MRSA infections. Objective: To compare the phenotypes and genotypes methods for identification of hospital isolates MRSA in Pereira. Methods: From isolates of S. aureus obtained of three high complexity institutions of health classified as A, B and C; determined resistance to Methicillin by minimum inhibitory concentration in automated systems and mecA gene by multiplex PCR. Results: The phenotype prevalence of MRSA was 44.4%, the institution A presented the highest rate with 48.65%. The genotype prevalence was 57.4%; in the institutions A, B and C was 55.2%, 41.7% and 75%, respectively, with difference statistically significant (p < 0.05). The sensitivity and specificity of the phenotype method were 99.0% and 94.7%, respectively, against the gold standard of the PCR method. The Kappa index was 0,942 indicating a very good level of concordance between methods. Conclusion: The prevalence of isolates MRSA in the institutions of Pereira was high. The concordance index of phenotype methods showed that they are reliable for the diagnosis of MRSA infections.

Drivers for Livestock-Associated Methicillin-Resistant Staphylococcus Aureus Spread Among Danish Pig Herds - A Simulation Study.

To gain insight into the rapid increase in the number of livestock-associated Methicillin-resistant Staphylococcus aureus (LA-MRSA)-positive herds in Denmark, we developed an individual-based Monte Carlo simulation model. We aimed to assess whether transmission of LA-MRSA via pig movements could explain the observed increase in the number of positive herds in Denmark, and to evaluate the effect of other between-herd transmission mechanisms. Pig movements alone were not sufficient to mimic the observed increase in LA-MRSA-positive herds in Denmark in any of the modelled scenarios. The model identified three factors that played important roles in the between-herd spread of LA-MRSA: (1) the within-herd dynamics, (2) the frequency and effectiveness of indirect transmissions, and (3) unexplainable introduction of LA-MRSA to swine herds. These factors can act as starting points for the development of LA-MRSA control programs in pig herds in order to limit the risk of its transmission to humans.

Effect of methicillin-resistant Staphylococcus aureus in Japan.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is the most common antimicrobial-resistant organism identified in Japanese health care facilities. This study analyzed the clinical and economic burdens attributable to methicillin resistance in S aureus in Japanese hospitals. METHODS: We retrospectively investigated data from 14,905 inpatients of 57 hospitals combined with data from nosocomial infection surveillance and administrative claim databases. The participants were inpatients with admission from April 1, 2014, to discharge on March 31, 2016. The outcomes were evaluated according to length of stay, hospital charges, and in-hospital mortality. We compared the disease burden of MRSA infections with methicillin-susceptible S aureus (MSSA) infections based on patients' characteristics and onset periods. RESULTS: We categorized 7,188 and 7,717 patients into MRSA and MSSA groups, respectively. The adjusted effects of the MRSA group were 1.03-fold (95% confidence interval [CI] 1.01-1.05) and 1.04-fold (95% CI, 1.01-1.06), respectively, with an odds ratio of 1.14 (95% CI, 1.02-1.27). CONCLUSIONS: The results of this study found that patient severity and onset delays were positively associated with both MRSA and burden and that the effect of methicillin resistance remained significant after adjustment.

Cost Efficacy of Methicillin-Resistant Staphylococcus aureus Decolonization With Intranasal Povidone-Iodine.

BACKGROUND: With increasing rates of virulent drug resistant organisms, MRSA (methicillin-resistant Staphylococcus aureus) decolonization has been demonstrated to decrease infection rates. Recent research has shown the antiseptic povidone-iodine to be equally effective and potentially cost saving compared to intranasal mupirocin. This study's purpose is to evaluate the incidence of MRSA colonization in a more rural community-based population, rates of infection on a mupirocin decolonization protocol, and develop a cost analysis model to compare costs of utilizing povidone-iodine. METHODS: Utilizing over 4 years of data, the incidence of MRSA decolonization of consecutive total knee and hip arthroplasties, as well as the rates of infection of patients uncolonized, colonized with successful decolonization, and unsuccessful decolonization were evaluated. Utilizing these data, cost data, and known infection rate utilizing povidone-iodine decolonization, a cost analysis model was developed. RESULTS: Of the 5584 cases with MRSA data at a single institution, only 3.5% tested positive for intranasal MRSA. Of those patients, 69% were successfully decolonized. Of the 3864 cases with infection data, 21 sustained a surgical site infection within 90 days (0.54%). Of these patients, all tested negative for intranasal MRSA initially and therefore did not undergo the decolonization protocol. The cost analysis predicts a potential savings of $74.72 per patient at our institution to use a global intranasal povidone-iodine protocol prior to total joint arthroplasty. CONCLUSION: Even with a lower incidence of MRSA than typically reported, utilization of intranasal povidone-iodine would potentially save $74.42 per patient.

Antibiotic susceptibility of methicillin-resistant staphylococci (MRS) of food origin: A comparison of agar disc diffusion method and a commercially available miniaturized test.

Methicillin-resistant staphylococci (MRS) are a major concern to public and animal health. Thirty MRS (Staphylococcus aureus, S. cohnii, S. epidermidis, S. haemolyticus, S. hominis, S. lentus, S. lugdunensis, S. sciuri, and S. xylosus) isolates from meat and poultry preparations were tested for antimicrobial susceptibility to 11 antimicrobials (belonging to seven different categories) of clinical significance using both the standard agar disc diffusion method and a commercially available miniaturized system (Sensi Test Gram-positive). It is worth stressing that 16 isolates (53.33%) exhibited an extensively drug-resistant phenotype (XDR). The average number of resistances per strain was 4.67. These results suggest that retail meat and poultry preparations are a likely vehicle for the transmission of multi-drug resistant MRS. Resistance to erythromycin was the commonest finding (76.67% of strains), followed by tobramycin, ceftazidime (66.67%), ciprofloxacin (56.67%) and fosfomycin (53.33%). An agreement (kappa coefficient) of 0.64 was found between the two testing methods. Using the agar disc diffusion as the reference method, the sensitivity, specificity and accuracy of the miniaturized test were 98.44%, 69.44% and 83.33%, respectively. Most discrepancies between the two methods were due to isolates that were susceptible according to the disc diffusion method but resistant according to the miniaturized test (false positives).

Livestock-associated meticillin-resistant Staphylococcus aureus (MRSA) among human MRSA isolates, European Union/European Economic Area countries, 2013.

Currently, surveillance of livestock-associated meticillin-resistant Staphylococcus aureus (LA-MRSA) in humans in Europe is not systematic but mainly event-based. In September 2014, the European Centre for Disease Prevention and Control (ECDC) initiated a questionnaire to collect data on the number of LA-MRSA from human samples (one isolate per patient) from national/regional reference laboratories in European Union/European Economic Area (EU/EEA) countries in 2013. Identification of LA-MRSA as clonal complex (CC) 398 by multilocus sequence typing (MLST) was preferred, although surrogate methods such as spa-typing were also accepted. The questionnaire was returned by 28 laboratories in 27 EU/EEA countries. Overall, LA-MRSA represented 3.9% of 13,756 typed MRSA human isolates, but it represented ≥ 10% in five countries (Belgium, Denmark, Spain, the Netherlands and Slovenia). Seven of the reference laboratories did not type MRSA isolates in 2013. To monitor the dispersion of LA-MRSA and facilitate targeted control measures, we advocate periodic systematic surveys or integrated multi-sectorial surveillance.