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.

Effect of Treating Parents Colonized With Staphylococcus aureus on Transmission to Neonates in the Intensive Care Unit: A Randomized Clinical Trial.

Importance: Staphylococcus aureus is a leading cause of health care-associated infections in the neonatal intensive care unit (NICU). Parents may expose neonates to S aureus colonization, a well-established predisposing factor to invasive S aureus disease. Objective: To test whether treating parents with intranasal mupirocin and topical chlorhexidine compared with placebo would reduce transmission of S aureus from parents to neonates. Design, Setting, and Participants: Double-blinded randomized clinical trial in 2 tertiary NICUs in Baltimore, Maryland. Neonates (n = 236) with S aureus-colonized parent(s) were enrolled. The study period was November 7, 2014, through December 13, 2018. Interventions: Parents were assigned to intranasal mupirocin and 2% chlorhexidine-impregnated cloths (active treatment, n = 117) or petrolatum intranasal ointment and nonmedicated soap cloths (placebo, n = 119) for 5 days. Main Outcomes and Measures: The primary end point was concordant S aureus colonization by 90 days, defined as neonatal acquisition of an S aureus strain that was the same strain as a parental strain at time of screening. Secondary outcomes included neonatal acquisition of any S aureus strain and neonatal S aureus infections. Results: Among 236 randomized neonates, 208 were included in the analytic sample (55% male; 76% singleton births; mean birth weight, 1985 g [SD, 958 g]; 76% vaginal birth; mean parent age, 31 [SD, 7] years), of whom 18 were lost to follow-up. Among 190 neonates included in the analysis, 74 (38.9%) acquired S aureus colonization by 90 days, of which 42 (56.8%) had a strain concordant with a parental baseline strain. In the intervention and placebo groups, 13 of 89 neonates (14.6%) and 29 of 101 neonates (28.7%), respectively, acquired concordant S aureus colonization (risk difference, -14.1% [95% CI, -30.8% to -3.9%]; hazard ratio [HR], 0.43 [95.2% CI, 0.16 to 0.79]). A total of 28 of 89 neonates (31.4%) in the intervention group and 46 of 101 (45.5%) in the control group acquired any S aureus strain (HR, 0.57 [95% CI, 0.31 to 0.88]), and 1 neonate (1.1%) in the intervention group and 1 neonate (1.0%) in the control group developed an S aureus infection before colonization. Skin reactions in parents were common (4.8% intervention, 6.2% placebo). Conclusions and Relevance: In this preliminary trial of parents colonized with S aureus, treatment with intranasal mupirocin and chlorhexidine-impregnated cloths compared with placebo significantly reduced neonatal colonization with an S aureus strain concordant with a parental baseline strain. However, further research is needed to replicate these findings and to assess their generalizability. Trial Registration: ClinicalTrials.gov Identifier: NCT02223520.

The design of civic technology: factors that influence public participation and impact.

Civic technology needs to be better understood in terms of the factors that promote representative public participation and impact. This paper reports on a mixed-methods study of a civic tech platform that enabled the public to provide feedback on public transport to the service providers. The overall aim of this research was to investigate the public's use of a leading civic tech platform, FixMyTransport. The key findings were that: an effective and easy-to-use civic technology platform enables broad participation; data and process complexity need to be removed; factual information can be captured in situ with impacts, consequences and opinions added later; emotions (if important) need to be explicitly elicited; feedback to, and a 'conversation' with, the users is important for engagement, as is a feeling of being part of a community. These findings can contribute to the future design of civic technology platforms. Practitioner Summary: There is a lack of understanding of how 'civic tech' platforms are used and how they may be designed for maximum effectiveness. Multiple data collection methods were used to investigate a well-developed example of civic tech. Effective civic tech can enable broad democratic participation to improve public services.

Comparison of five chromogenic media for recovery of vancomycin-resistant enterococci from fecal samples.

Five chromogenic agars, evaluated using 400 stool specimens, were found to be superior in sensitivity (range, 89.9 to 93.9%) to bile esculin azide agar with vancomycin (BEAV) agar (84.8%) for detecting vancomycin-resistant enterococci (VRE), and the results were available 24 to 48 h sooner. The time to detection, need for supplemental testing, color distinction, and breakthrough of non-VRE organisms vary among the chromogenic media tested and may factor into the decision to use a particular medium.

Impact of colonization pressure and strain type on methicillin-resistant Staphylococcus aureus transmission in children.

We studied the transmissibility of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) and healthcare-associated methicillin-resistant S. aureus (HA-MRSA) strains and the association of MRSA colonization pressure and MRSA transmission in critically ill children. Importantly, we found that in hospitalized children MRSA colonization pressure above 10% increases the risk of MRSA transmission 3-fold, and CA-MRSA and HA-MRSA strains have similar transmission dynamics.

An evaluation of environmental decontamination with hydrogen peroxide vapor for reducing the risk of patient acquisition of multidrug-resistant organisms.

BACKGROUND: Admission to a room previously occupied by a patient with certain multidrug-resistant organisms (MDROs) increases the risk of acquisition. Traditional cleaning strategies do not remove all environmental MDROs. We evaluated the environmental and clinical impact of hydrogen peroxide vapor (HPV) room disinfection. METHODS: We performed a 30-month prospective cohort intervention study on 6 high-risk units in a 994-bed tertiary care hospital. Following a 12-month preintervention phase, HPV was implemented on 3 units to decontaminate the rooms of patients known to be infected or colonized with epidemiologically important MDROs, following their discharge. Monthly environmental samples for MDROs were collected on all study units for 3 preintervention and 6 intervention months. The risk of MDRO acquisition in patients admitted to rooms decontaminated using HPV was compared with rooms disinfected using standard methods. RESULTS: The prior room occupant was known to be infected or colonized with an MDRO in 22% of 6350 admissions. Patients admitted to rooms decontaminated using HPV were 64% less likely to acquire any MDRO (incidence rate ratio [IRR], 0.36; 95% confidence interval [CI], .19-.70; P < .001) and 80% less likely to acquire VRE (IRR, 0.20; 95% CI, .08-.52; P < .001) after adjusting for other factors. The risk of acquiring Clostridium difficile, methicillin-resistant Staphylococcus aureus, and multidrug-resistant gram-negative rods individually was reduced, but not significantly. The proportion of rooms environmentally contaminated with MDROs was reduced significantly on the HPV units (relative risk, 0.65, P = .03), but not on non-HPV units. CONCLUSIONS: HPV decontamination reduced environmental contamination and the risk of acquiring MDROs compared with standard cleaning protocols.

Past history of skin infection and risk of surgical site infection after elective surgery.

OBJECTIVE: To identify baseline patient characteristics associated with increased susceptibility to surgical site infection (SSI) after elective surgery. BACKGROUND: The Center for Medicare and Medicaid Services considers SSI to be preventable through adherence to current infection control practices; however, the etiology of wound infection is incompletely understood. METHODS: Prospective cohort study involving patients undergoing cardiac, vascular, craniotomy, and spinal surgery at 2 academic medical centers in Baltimore, MD. A comprehensive medical history was obtained at baseline, and participants were followed for 6 months using active inpatient and outpatient surveillance for deep SSI and infectious death. Infection control best practices were monitored perioperatively. The relative risk of SSI/infectious death was determined comparing those with versus those without a past medical history of skin infection using Cox proportional hazards models. RESULTS: Of 613 patients (mean [SD] = 62.3 [11.5] years; 42.1% women), 22.0% reported a history of skin infection. The cumulative incidence of deep SSI/infectious death was 6.7% versus 3.1% for those with and without a history of skin infection, respectively (unadjusted hazard ratio (HR) = 2.25; 95% confidence interval (95% CI), 0.98-5.14; P = 0.055). Risk estimates increased after adjustments for demographic and socioeconomic variables (HR = 2.82; 95% CI, 1.18-6.74; P = 0.019) and after propensity score adjustment for all potential confounders (HR = 3.41; 95% CI, 1.36-8.59; P = 0.009). Adjustments for intraoperative infection risk factors and adherence to infection control best practice metrics had no impact on risk estimates. CONCLUSIONS: A history of skin infection identified a state of enhanced susceptibility to SSI at baseline that is independent of traditional SSI risk factors and adherence to current infection control practices.

Methicillin-resistant Staphylococcus aureus colonization and risk of subsequent infection in critically ill children: importance of preventing nosocomial methicillin-resistant Staphylococcus aureus transmission.

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) colonization is a predictor of subsequent infection in hospitalized adults. The risk of subsequent MRSA infections in hospitalized children colonized with MRSA is unknown. METHODS: Children admitted to an academic medical center's pediatric intensive care unit between March 2007 and March 2010 were included in the study. Anterior naris swabs were cultured to identify children with MRSA colonization at admission. Laboratory databases were queried and National Healthcare Safety Network definitions applied to identify patients with MRSA infections during their hospitalization or after discharge. RESULTS: The MRSA admission prevalence among 3140 children was 4.9%. Overall, 56 children (1.8%) developed an MRSA infection, including 13 (8.5%) colonized on admission and 43 (1.4%) not colonized on admission (relative risk [RR], 5.9; 95% confidence interval [CI], 3.4-10.1). Of those, 10 children (0.3%) developed an MRSA infection during their hospitalization, including 3 of 153 children (1.9%) colonized on admission and 7 of 2987 children (0.2%) not colonized on admission (RR, 8.4; 95% CI, 2.7-25.8). African-Americans and those with public health insurance were more likely to get a subsequent infection (P < .01 and P = .03, respectively). We found that 15 children acquired MRSA colonization in the pediatric intensive care unit, and 7 (47%) developed a subsequent MRSA infection. CONCLUSIONS: MRSA colonization is a risk factor for subsequent MRSA infection in children. Although MRSA colonized children may have lower risks of subsequent infection than adults, children who acquire MRSA in the hospital have similarly high rates of infection. Preventing transmission of MRSA in hospitalized children should remain a priority.

Community-associated methicillin-resistant Staphylococcus aureus strains in pediatric intensive care unit.

Virulent community-associated methicillin-resistant Staphylococcus-aureus (CA-MRSA) strains have spread rapidly in the United States. To characterize the degree to which CA-MRSA strains are imported into and transmitted in pediatric intensive care units (PICU), we performed a retrospective study of children admitted to The Johns Hopkins Hospital PICU, March 1, 2007-May 31, 2008. We found that 72 (6%) of 1,674 PICU patients were colonized with MRSA. MRSA-colonized patients were more likely to be younger (median age 3 years vs. 5 years; p = 0.02) and African American (p<0.001) and to have been hospitalized within 12 months (p<0.001) than were noncolonized patients. MRSA isolates from 66 (92%) colonized patients were fingerprinted; 40 (61%) were genotypically CA-MRSA strains. CA-MRSA strains were isolated from 50% of patients who became colonized with MRSA and caused the only hospital-acquired MRSA catheter-associated bloodstream infection in the cohort. Epidemic CA-MRSA strains are becoming endemic to PICUs, can be transmitted to hospitalized children, and can cause invasive hospital-acquired infections. Further appraisal of MRSA control is needed.

Evaluation of BBL CHROMagar VanRE for detection of vancomycin-resistant Enterococci in rectal swab specimens.

A study was performed on 517 surveillance rectal swabs to evaluate a selective and differential chromogenic medium, the BBL CHROMagar VanRE (CVRE), which enables recovery and identification of VanA- and VanB-containing Enterococcus faecium (ENFM) and Enterococcus faecalis (ENFS) isolates. Compared to BBL Enterococcosel agar, a bile-esculin-azide-vancomycin (BEAV) agar, the initial overall sensitivity, specificity, and positive and negative predictive values of CVRE for the detection of vancomycin-resistant ENFM and ENFS were 99.1% and 94.8% and 84.2% and 99.7%, respectively. Among our patient population, more vancomycin-resistant enterococci (VRE) were recovered with CVRE than BEAV.

The personal and contextual factors that affect customer experience during rail service failures and the implications for service design.

This paper: identifies personal and contextual factors that influence customer experience when service failures occur in rail transport; what is being conveyed through that factor (e.g. older age being used to convey vulnerability); and the implications for future service design. The results are from a thematic analysis of free-text rail passenger complaints (n = 516) reporting service failures that impacted on customer experience. The study differs from existing research on the pertinent personal and contextual factors for public transport service provision in that it: focuses on the passenger experience resulting from specific incidents (rather than evaluative, overall assessments of satisfaction), generates the factors inductively from the data (rather than a-priori) and uses detailed qualitative cases (rather than quantitative survey data). The findings (1) identify some similar factors to those used in previous research and uncover some new factors for both person and context, (2) provide an understanding of what they mean in terms of the passenger experience and (3) indicate how the factors might need to be measured if they are to be used by the rail industry. The paper concludes by using the outcome of an industry-based validation exercise to describe how the findings could be used in future rail services, namely: predicting where the customer experience is going to be sub-optimal, prioritising responses to particular circumstances, and designing services to better meet customer's needs. This exploratory research is timely, given the need for a more passenger-centric approach to service design and future developments such as smart-ticketing, which could potentially enable greater understanding of who is using the rail network and for what journeys.

Sphingomonas paucimobilis bloodstream infections associated with contaminated intravenous fentanyl.

Nationally distributed medications from compounding pharmacies, which typically adhere to less stringent quality-control standards than pharmaceutical manufacturers, can lead to multistate outbreaks. We investigated a cluster of 6 patients in a Maryland hospital who had Sphingomonas paucimobilis bloodstream infections in November 2007. Of the 6 case-patients, 5 (83%) had received intravenous fentanyl within 48 hours before bacteremia developed. Cultures of unopened samples of fentanyl grew S. paucimobilis; the pulsed-field gel electrophoresis pattern was indistinguishable from that of the isolates of 5 case-patients. The contaminated fentanyl lot had been prepared at a compounding pharmacy and distributed to 4 states. Subsequently, in California, S. paucimobilis bacteremia was diagnosed for 2 patients who had received intravenous fentanyl from the same compounding pharmacy. These pharmacies should adopt more stringent quality-control measures, including prerelease product testing, when compounding and distributing large quantities of sterile preparations.

Rapid molecular genotyping and clonal complex assignment of Staphylococcus aureus isolates by PCR coupled to electrospray ionization-mass spectrometry.

We describe a high-throughput assay using PCR coupled to electrospray ionization-mass spectrometry (PCR/ESI-MS) to determine the genotypes of Staphylococcus aureus isolates. The primer sets used in the PCR/ESI-MS assay were designed to amplify the same genes analyzed in multilocus sequence typing (MLST). The method was used to identify the clonal complex and USA type of each isolate and is suitable for use in a clinical or public-health setting. The method was validated using a panel of diverse isolates from the Centers for Disease Control and Prevention that were previously characterized by MLST and pulsed-field gel electrophoresis (PFGE). Clinical isolates from two geographically distinct hospitals were characterized, and the clustering results were in agreement with those for repetitive-element PCR and PFGE. The PCR/ESI-MS method enables genotyping of over 180 samples of S. aureus per day in an automated fashion.

Discordance between Staphylococcus aureus nasal colonization and skin infections in children.

We examined nasal carriage of Staphylococcus aureus in otherwise healthy children presenting with skin and soft tissue infections. We found high rates of nasal colonization with S. aureus, but significant discordance between nasal and wound isolates. Recurrent skin and soft tissue infections were common but unrelated to baseline methicillin-resistant S. aureus nasal colonization status.

The impact of chlorhexidine gluconate bathing on skin bacterial burden of neonates admitted to the Neonatal Intensive Care Unit.

OBJECTIVE: To assess the impact of chlorhexidine gluconate (CHG) bathing on skin bacterial burden in neonates. STUDY DESIGN: In this prospective observational study, arm and groin skin bacterial growth was measured in 40 CHG-exposed and nonexposed neonates admitted to the NICU. Exposed neonates received 2% CHG baths per protocol for central line-associated bloodstream infection (CLABSI) prevention or Staphylococcus aureus decolonization. RESULTS: Forty neonates were enrolled, 18 of whom were CHG-exposed. Mean baseline Gram-positive (GP) bacterial burden was 2.19 log CFU/ml on the arm and 1.81 log CFU/ml on the groin. Bacterial burden decreased after the first bath, but returned to baseline by 72 h. Residual skin CHG concentration declined over time, with a corresponding increase in GP bacterial burden. CONCLUSIONS: CHG bathing reduces skin bacterial burden, but burden returns to baseline after 72 h. Twice weekly CHG bathing may be inadequate to suppress skin bacterial growth in hospitalized neonates.

Comparison of the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture by use of BBL CHROMagar MRSA for detection of MRSA in nasal surveillance cultures from an at-risk community population.

We compared the BD GeneOhm methicillin-resistant Staphylococcus aureus (MRSA) PCR assay to culture with BBL CHROMagar MRSA for nasal surveillance among 602 arrestees from the Baltimore City Jail. The sensitivity and specificity were 88.5% and 91.0%, respectively, and after secondary analysis using enrichment broth, they were 89.0% and 91.7%, respectively. Twenty-three of 42 false-positive PCR lysates contained methicillin-susceptible S. aureus.

Outbreak of multidrug-resistant Serratia marcescens infection in a neonatal intensive care unit.

BACKGROUND: Serratia marcescens causes healthcare-associated infections and significant morbidity and mortality in neonatal intensive care units (NICUs). We report the investigation and control of an outbreak of multidrug-resistant (MDR) S. marcescens infection at an NICU. METHODS: An outbreak investigation and a case-control study were undertaken at a 36-bed NICU in a tertiary care hospital in Baltimore, Maryland, for the period from October 2004 through February 2005. The outbreak investigation included case identification, review of medical records, environmental cultures, patient surveillance cultures, personnel hand cultures, and pulsed-field gel electrophoresis (PFGE). The case-control study included case identification and review of medical records. Infection control measures were implemented. Eighteen NICU neonates had cultures that grew MDR S. marcescens during the study period. The case-control study included 16 patients with the outbreak strain or an unidentified strain of MDR S. marcescens and 32 control patients not infected and/or colonized with MDR S. marcescens, treated in the NICU for at least 48 hours during the study period. RESULTS: PFGE analysis identified a single strain of MDR S. marcescens that infected or colonized 15 patients. Two patients had unique strains, and 1 patient's isolate could not be subtyped. An unrelated MDR S. marcescens isolate was recovered from a sink drain. Exposure to inhalational therapy was an independent risk factor for MDR S. marcescens acquisition after adjusting for birth weight. Extensive investigation failed to reveal a point source for the outbreak. CONCLUSION: A single epidemic strain of MDR S. marcescens spread rapidly and threatened to become endemic in this NICU. Transient carriage on the hands of healthcare personnel or on respiratory care equipment was the likely mode of transmission. Cohorting patients and staff, at the cost of bed closures and additional personnel, interrupted transmission and halted the outbreak.

Epidemiology and risk factors for recurrent Staphylococcus aureus colonization following active surveillance and decolonization in the NICU.

OBJECTIVES: To examine neonatal risk factors associated with recurrent Staphylococcus aureus colonization and to determine the genetic relatedness of S. aureus strains cultured from neonates before and after decolonization.Study designSingle-center retrospective cohort study of neonates admitted to the neonatal intensive care unit (NICU) from April 2013 to December 2015, during which weekly nasal cultures from hospitalized NICU patients were routinely obtained for S. aureus surveillance. SETTING: Johns Hopkins Hospital's 45-bed level IV NICU in Baltimore, Maryland. METHODS: Demographics and clinical data were collected on all neonates admitted to the NICU with S. aureus nasal colonization who underwent mupirocin-based decolonization during the study period. A decolonized neonate was defined as a neonate with ≥1 negative culture after intranasal mupirocin treatment. Pulsed-field gel electrophoresis was used for strain typing. RESULTS: Of 2,060 infants screened for S. aureus, 271 (13%) were colonized, and 203 of these 271 (75%) received intranasal mupirocin. Of those treated, 162 (80%) had follow-up surveillance cultures, and 63 of these 162 infants (39%) developed recurrent colonization after treatment. The S. aureus strains were often genetically similar before and after decolonization. The presence of an endotracheal tube or nasal cannula/mask was associated with an increased risk of recurrent S. aureus colonization (hazard ratio [HR], 2.65; 95% confidence interval [CI], 1.19-5.90; and HR, 2.21; 95% CI, 1.02-4.75, respectively). CONCLUSION: Strains identified before and after decolonization were often genetically similar, and the presence of invasive respiratory devices increased the risk of recurrent S. aureus nasal colonization in neonates. To improve decolonization efficacy, alternative strategies may be needed.

An outbreak of Pseudomonas aeruginosa infections associated with flexible bronchoscopes.

BACKGROUND: Endoscopes, including bronchoscopes, are the medical devices most frequently associated with outbreaks of nosocomial infections. We investigated an outbreak of Pseudomonas aeruginosa infections after bronchoscopic procedures. METHODS: Microbiologic results were reviewed to determine the rates of recovery of P. aeruginosa from bronchoalveolar-lavage specimens. Environmental samples from endoscopes and the endoscopy suite were cultured. Medical records were reviewed to identify infections in the 14 days after a bronchoscopy. RESULTS: The rate of recovery of P. aeruginosa from bronchoalveolar-lavage specimens obtained with use of endoscopy-suite bronchoscopes increased from 10.4 percent at base line to 31.0 percent during the outbreak (relative risk, 2.97; 95 percent confidence interval, 2.28 to 3.90). Cultures of samples from three bronchoscopes grew P. aeruginosa, whereas cultures of samples from the environment, instrument-cleaning machines, and gastrointestinal endoscopes did not. The three bronchoscopes had been part of a nationwide recall. A total of 414 patients underwent bronchoscopy during the outbreak, and there were 48 respiratory tract and bloodstream infections among 39 of these patients (9.4 percent). In 32 infections (66.7 percent), P. aeruginosa was confirmed as a potentially causative organism. Exposure to a potentially contaminated bronchoscope may have had a role in the death of three patients. The rate of recovery of P. aeruginosa returned to base line after the instruments were removed from service. CONCLUSIONS: This large outbreak of P. aeruginosa infections related to bronchoscopy was apparently caused by a loose biopsy-port cap in the bronchoscopes. Instrument safety and surveillance methods for bronchoscopy must be improved, and better recall procedures are needed for medical devices.