Norovirus and Clostridium difficile outbreaks: squelching the wildfire.

PURPOSE OF REVIEW: Gastrointestinal outbreaks in the healthcare setting cause increased morbidity and mortality in an already vulnerable population. Optimization of infection prevention measures can be a challenge in healthcare settings. This review describes new literature that may change the traditional infection prevention approach to such outbreaks. RECENT FINDINGS: Asymptomatic carriers of both norovirus and Clostridium difficile can pose risk of transmission to others and the environment. Rapid recognition and diagnosis can decrease the extent of an outbreak. No-touch technologies for environmental disinfection are new and effective tools. Infection prevention consultant services and systems redesign can augment efforts to control baseline infection rates and outbreaks. Antimicrobial stewardship continues to be essential to prevent C. difficile infection. SUMMARY: New approaches are needed to stem the tide of norovirus and C. difficile clusters and outbreaks in healthcare settings. Accurate recognition, testing, and implementation of infection prevention measures can be supported with rapid testing modalities, access to updated guidelines and no-touch disinfection systems. The work-environment culture should be carefully assessed and restructured using human engineering models to promote effective infection prevention practices. Antimicrobial stewardship initiatives are needed at the bedside and at national levels.

The clinical and molecular epidemiology of pre-transplant vancomycin-resistant enterococci colonization among liver transplant recipients.

Vancomycin-resistant enterococci (VRE) infections cause significant morbidity in liver transplant recipients. The epidemiology and impact of pre-transplant colonization with VRE among patients who undergo liver transplantation are poorly understood. We conducted an observational cohort study to identify risk factors and outcomes associated with pre-transplant VRE colonization and described the molecular diversity among VRE strains colonizing patients who undergo liver transplantation. Perirectal VRE surveillance cultures were performed prior to transplantation. Repetitive sequence-based polymerase chain reaction (rep-PCR) testing was used to identify clonality among VRE isolates. Of 61 patients who underwent pre-transplant VRE surveillance and subsequent liver transplantation, 27 (44%) were colonized with VRE. In multivariate analysis, pre-transplant VRE colonization was associated with central venous catheterization (OR 9.4, 95% confidence interval [CI]= 1.3-70.2, p = 0.03) and rifaximin use (OR 15.4, 95% CI 1.5-159.7, p = 0.02). Pre-transplant VRE colonization was associated with more hospital days post-transplant (26.6 vs. 16.1 d, p = 0.04). Of VRE-colonized patients analyzed with rep-PCR, 68% were colonized with the same strain as another patient in the cohort. Active surveillance identifies VRE-colonized patients who may benefit from targeted antimicrobial prophylaxis and enhanced infection prevention measures to prevent VRE spread. The relationship between rifaximin receipt and VRE colonization warrants further study. The identification of similar VRE isolates may suggest linked transmission during pre-transplant hospitalizations, which should be further investigated in prospective studies.

Clinical and Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus in a Neonatal Intensive Care Unit in the Decade following Implementation of an Active Detection and Isolation Program.

Methicillin-resistant Staphylococcus aureus (MRSA) is a frequent source of infection in the neonatal intensive care unit (NICU), often associated with significant morbidity. Active detection and isolation (ADI) programs aim to reduce transmission. We describe a comprehensive analysis of the clinical and molecular epidemiology of MRSA in an NICU between 2003 and 2013, in the decade following the implementation of an MRSA ADI program. Molecular analyses included strain typing by pulsed-field gel electrophoresis, mec and accessory gene regulator group genotyping by multiplex PCR, and identification of toxin and potential virulence factor genes via PCR-based assays. Of 8,387 neonates, 115 (1.4%) had MRSA colonization and/or infection. The MRSA colonization rate declined significantly during the study period from 2.2 to 0.5/1,000 patient days (linear time, P = 0.0003; quadratic time, P = 0.006). There were 19 cases of MRSA infection (16.5%). Few epidemiologic or clinical differences were identified between MRSA-colonized and MRSA-infected infants. Thirty-one different strains of MRSA were identified with a shift from hospital-associated to combined hospital- and community-associated strains over time. Panton-Valentine leukocidin-positive USA300 strains caused 5 of the last 11 infections. Staphylococcal cassette chromosome mec (SCCmec) types II and IVa and agr groups 1 and 2 were most predominant. One isolate possessed the gene for toxic shock syndrome toxin; none had genes for exfoliative toxin A or B. These results highlight recent trends in MRSA colonization and infection and the corresponding changes in molecular epidemiology. Continued vigilance for this invasive pathogen remains critical, and specific attention to the unique host, the neonate, and the distinct environment, the NICU, is imperative.

Antimicrobial Stewardship Optimization in the Emergency Department: The Effect of Multiplex Respiratory Pathogen Testing and Targeted Educational Intervention.

BACKGROUND: Antibacterial agents are often prescribed for patients with suspected respiratory tract infections even though these are most often caused by viruses. In this study, we sought to evaluate the effect of Respiratory Pathogen Panel (RPP) PCR result availability and antimicrobial stewardship education on antibiotic prescription rates in the adult emergency department (ED). METHODS: We compared rates of antibacterial and oseltamivir prescriptions between 2 nonconsecutive influenza seasons among ED visits, wherein the latter season followed the implementation of a comprehensive educational stewardship campaign. In addition, we sought to elucidate the effect of RPP-PCR on antibiotic prescriptions, with focus on result availability prior to the conclusion of emergency department encounters. RESULTS: Antibiotic prescription rates globally decreased by 17.9% in the FS-17/18 cohort compared to FS-14/15 (P < 0.001), while oseltamivir prescription rates stayed the same overall (P = 0.42). Multivariate regression across both cohorts revealed that patients were less likely to receive antibiotics if RPP-PCR results were available before the end of the ED visit or if the RPP-PCR result was positive for influenza. Patients in the educational intervention cohort were also less likely to receive an antibiotic prescription. CONCLUSION: This study provides evidence that RPP-PCR results are most helpful if available prior to the end of the provider-patient interaction. Further, these data suggest that detection of influenza remains an influential result in the context of antimicrobial treatment decision making. In addition, these data contribute to the body of literature which supports comprehensive ASP interventions including leadership and patient engagement.

SARS-CoV-2 detection in setting of viral swabs scarcity: Are MRSA swabs and viral swabs equivalent?

BACKGROUND: The global pandemic of Severe Acute Respiratory Syndrome-Related Coronavirus 2 (SARS-CoV2) has resulted in unprecedented challenges for healthcare systems. One barrier to widespread testing has been a paucity of traditional respiratory viral swab collection kits relative to the demand. Whether other sample collection kits, such as widely available MRSA nasal swabs can be used to detect SARS-CoV-2 is unknown. METHODS: We compared simultaneous nasal MRSA swabs (COPAN ESwabs ® 480C flocked nasal swab in 1mL of liquid Amies medium) and virals wabs (BD H192(07) flexible mini-tip flocked nasopharyngeal swabs in 3mL Universal Transport Medium) for SARS-CoV-2 PCR testing using Simplexa COVID-19 Direct assay on patients over a 4-day period. When the results were discordant, the viral swab sample was run again on the Cepheid Xpert Xpress ® SARS-CoV-2 assay. RESULTS: Of the 81 included samples, there were 19 positives and 62 negatives in viral media and 18 positives and 63 negative in the MRSA swabs. Amongst all included samples, there was concordance between the COPAN ESwabs ® 480C and the viral swabs in 78 (96.3%). CONCLUSION: We found a high rate of concordance in test results between COPAN ESwabs ® 480C in Amies solution and BD H192(07) nasopharyngeal swabs in in 3 mL of Universal Viral Transport medium viral media. Clinicians and laboratories should feel better informed and assured using COPAN ESwabs ® 480C to help in the diagnosis of COVID-19.

Epidemiology of Clostridium difficile infection in hospitalized oncology patients.

The epidemiology of Clostridium difficile infection (CDI) among oncology inpatients is poorly understood. In multivariate analysis we identified age, history of CDI, and prior receipt of cephalosporins, ß-lactam/ß-lactamase inhibitors, metronidazole, and blood transfusion as risk factors associated with CDI. Reducing broad-spectrum antibiotic use, particularly among older patients and those with a CDI history and recent blood transfusions, may decrease CDI risk in this population.

Validation of the surveillance and reporting of central line-associated bloodstream infection denominator data.

BACKGROUND: While the main focus of validating central line-associated infections (CLABIs) has been applying strict definitions to identify cases, assessing the denominator counts has received less attention. This study evaluates the accuracy of the reporting of CLABSI denominator patient-day (PD) and central line-day (CLD) counts to the National Healthcare Safety Network (NHSN) system in one state. METHODS: The Connecticut Department of Public Health (CT DPH) performed a blinded retrospective chart review on the collection of CLABSI PD and CLD on 9 selected days during the fourth quarter of 2009 from 23 acute care hospitals. RESULTS: Overall, 1,988 intensive care unit patient charts were reviewed. Comparison of hospital and CT DPH counts identified over-reporting by 300 PD (17.2%) and 200 CLD (21.7%) with 17 hospitals (74%) collecting data manually. PD manual collection methods were more accurate than electronic methods (P < .01). For CLD, there was no significant difference in collection method (P > .05). Wednesday PD counts were more accurate than Monday (P < .05) or Saturday (P < .05). For CLD counts, there was no significant difference among the 3 days (P > .05). CONCLUSION: Our results provide some evidence for the prerequisite internal validation of denominator data by hospitals before reporting to the national surveillance system.

Antimicrobial activities of BMS-284756 compared with those of fluoroquinolones and beta-lactams against gram-positive clinical isolates.

The in vitro antibacterial activity of BMS-284756 was compared to those of ciprofloxacin, gatifloxacin, moxifloxacin, ceftriaxone, imipenem, piperacillin-tazobactam, and amoxicillin-clavulanic acid against 492 gram-positive clinical isolates. BMS-284756 was the most-active agent against Streptococcus pneumoniae, Streptococcus viridans, beta-hemolytic streptococci, methicillin-sensitive and -resistant Staphylococcus aureus, methicillin-sensitive and -resistant coagulase-negative staphylococci, and enterococci.