The best strategy for controlling extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) transmission in intensive care units (ICUs) remains elusive.

We developed a stochastic transmission model to quantify the effectiveness of interventions aimed at reducing the spread of ESBL-PE in an ICU.

We modeled the evolution of an outbreak caused by the admission of a single carrier in a 10-bed ICU free of ESBL-PE. Using data obtained from recent muticenter studies, we studied 26 strategies combining different levels of the following 3 interventions: (1) increasing healthcare worker compliance with hand hygiene before and after contact with a patient; (2) cohorting; (3) reducing antibiotic prevalence at admission with or without reducing antibiotherapy duration.

Improving hand hygiene compliance from 55% before patient contact and 60% after patient contact to 80% before and 80% after patient contact reduced the nosocomial incidence rate of ESBL-PE colonization by 91% at 90 days. Adding cohorting to hand hygiene improvement intervention decreased the proportion of ESBL-PE acquisitions by an additional 7%. Antibiotic restriction had the lowest impact on the epidemic. When combined with other interventions, it only marginally improved effectiveness, despite strong hypotheses regarding antibiotic impact on transmission.

Our results suggest that hand hygiene is the most effective intervention to control ESBL-PE transmission in an ICU.

Infect. Control Hosp. Epidemiol. 2016;37(3):272–280

Ebola virus disease (EVD) places healthcare personnel (HCP) at high risk for infection during patient care, and personal protective equipment (PPE) is critical. Protocols for EVD PPE doffing have not been validated for prevention of viral self-contamination. Using surrogate viruses (non-enveloped MS2 and enveloped Φ6), we assessed self-contamination of skin and clothes when trained HCP doffed EVD PPE using a standardized protocol.

A total of 15 HCP donned EVD PPE for this study. Virus was applied to PPE, and a trained monitor guided them through the doffing protocol. Of the 15 participants, 10 used alcohol-based hand rub (ABHR) for glove and hand hygiene and 5 used hypochlorite for glove hygiene and ABHR for hand hygiene. Inner gloves, hands, face, and scrubs were sampled after doffing.

After doffing, MS2 virus was detected on the inner glove worn on the dominant hand for 8 of 15 participants, on the non-dominant inner glove for 6 of 15 participants, and on scrubs for 2 of 15 participants. All MS2 on inner gloves was observed when ABHR was used for glove hygiene; none was observed when hypochlorite was used. When using hypochlorite for glove hygiene, 1 participant had MS2 on hands, and 1 had MS2 on scrubs.

A structured doffing protocol using a trained monitor and ABHR protects against enveloped virus self-contamination. Non-enveloped virus (MS2) contamination was detected on inner gloves, possibly due to higher resistance to ABHR. Doffing protocols protective against all viruses need to incorporate highly effective glove and hand hygiene agents.

Infect Control Hosp Epidemiol 2016;1–6

Bloodstream infection (BSI) due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with considerable morbidity and mortality.

To determine the incidence of MRSA BSI in Canadian hospitals and to identify variables associated with increased mortality.

Prospective surveillance for MRSA BSI conducted in 53 Canadian hospitals from January 1, 2008, through December 31, 2012. Thirty-day all-cause mortality was determined, and logistic regression analysis was used to identify variables associated with mortality.

A total of 1,753 patients with MRSA BSI were identified (incidence, 0.45 per 1,000 admissions). The most common sites presumed to be the source of infection were skin/soft tissue (26.6%) and an intravascular catheter (22.0%). The most common spa types causing MRSA BSI were t002 (USA100/800; 55%) and t008 (USA300; 29%). Thirty-day all-cause mortality was 23.8%. Mortality was associated with increasing age (odds ratio, 1.03 per year [95% CI, 1.02–1.04]), the presence of pleuropulmonary infection (2.3 [1.4–3.7]), transfer to an intensive care unit (3.2 [2.1–5.0]), and failure to receive appropriate antimicrobial therapy within 24 hours of MRSA identification (3.2 [2.1–5.0]); a skin/soft-tissue source of BSI was associated with decreased mortality (0.5 [0.3–0.9]). MRSA genotype and reduced susceptibility to vancomycin were not associated with risk of death.

This study provides additional insight into the relative impact of various host and microbial factors associated with mortality in patients with MRSA BSI. The results emphasize the importance of ensuring timely receipt of appropriate antimicrobial agents to reduce the risk of an adverse outcome.

Infect. Control Hosp. Epidemiol. 2016;37(4):390–397

Antimicrobial stewardship programs (ASPs) are variably implemented.

To characterize variations of antimicrobial stewardship structure and practices across all inpatient Veterans Affairs facilities in 2012 and correlate key characteristics with antimicrobial usage.

A web-based survey regarding stewardship activities was administered to each facility’s designated contact. Bivariate associations between facility characteristics and inpatient antimicrobial use during 2012 were determined.

Total of 130 Veterans Affairs facilities with inpatient services.

Of 130 responding facilities, 29 (22%) had a formal policy establishing an ASP, and 12 (9%) had an approved ASP business plan. Antimicrobial stewardship teams were present in 49 facilities (38%); 34 teams included a clinical pharmacist with formal infectious diseases (ID) training. Stewardship activities varied across facilities, including development of yearly antibiograms (122 [94%]), formulary restrictions (120 [92%]), stop orders for antimicrobial duration (98 [75%]), and written clinical pathways for specific conditions (96 [74%]). Decreased antimicrobial usage was associated with having at least 1 full-time ID physician (P=.03), an ID fellowship program (P=.003), and a clinical pharmacist with formal ID training (P=.006) as well as frequency of systematic patient-level reviews of antimicrobial use (P=.01) and having a policy to address antimicrobial use in the context of Clostridium difficile infection (P=.01). Stop orders for antimicrobial duration were associated with increased use (P=.03).

ASP-related activities varied considerably. Decreased antibiotic use appeared related to ID presence and certain select practices. Further statistical assessments may help optimize antimicrobial practices.

Infect Control Hosp Epidemiol 2016;37:647–654

Central-line–associated bloodstream infection (CLABSI) rate is an important quality measure, but it suffers from subjectivity and interrater variability, and decreasing national CLABSI rates may compromise its power to discriminate between hospitals. This study evaluates hospital-onset bacteremia (HOB, ie, any positive blood culture obtained 48 hours post admission) as a healthcare-associated infection–related outcome measure by assessing the association between HOB and CLABSI rates and comparing the power of each to discriminate quality among intensive care units (ICUs).

In this multicenter study, ICUs provided monthly CLABSI and HOB rates for 2012 and 2013. A Poisson regression model was used to assess the association between these 2 rates. We compared the power of each measure to discriminate between ICUs using standardized infection ratios (SIRs) with 95% confidence intervals (CIs). A measure was defined as having greater power to discriminate if more of the SIRs (with surrounding CIs) were different from 1.

In 80 ICUs from 16 hospitals in the United States and Canada, a total of 663 CLABSIs, 475,420 central line days, 11,280 HOBs, and 966,757 patient days were reported. An absolute change in HOB of 1 per 1,000 patient days was associated with a 2.5% change in CLABSI rate (P<.001). Among the 80 ICUs, 20 (25%) had a CLABSI SIR and 60 (75%) had an HOB SIR that was different from 1 (P<.001).

Change in HOB rate is strongly associated with change in CLABSI rate and has greater power to discriminate between ICU performances. Consideration should be given to using HOB to replace CLABSI as an outcome measure in infection prevention quality assessments.

Infect. Control Hosp. Epidemiol. 2016;37(2):143–148

To study the association between gastrointestinal colonization of carbapenemase-producing Enterobacteriaceae (CPE) and proton pump inhibitors (PPIs).

We analyzed 31,526 patients with prospective collection of fecal specimens for CPE screening: upon admission (targeted screening) and during hospitalization (opportunistic screening, safety net screening, and extensive contact tracing), in our healthcare network with 3,200 beds from July 1, 2011, through December 31, 2015. Specimens were collected at least once weekly during hospitalization for CPE carriers and subjected to broth enrichment culture and multiplex polymerase chain reaction.

Of 66,672 fecal specimens collected, 345 specimens (0.5%) from 100 patients (0.3%) had CPE. The number and prevalence (per 100,000 patient-days) of CPE increased from 2 (0.3) in 2012 to 63 (8.0) in 2015 (P<.001). Male sex (odds ratio, 1.91 [95% CI, 1.15–3.18], P=.013), presence of wound or drain (3.12 [1.70–5.71], P<.001), and use of cephalosporins (3.06 [1.42–6.59], P=.004), carbapenems (2.21 [1.10–4.48], P=.027), and PPIs (2.84 [1.72–4.71], P<.001) in the preceding 6 months were significant risk factors by multivariable analysis. Of 79 patients with serial fecal specimens, spontaneous clearance of CPE was noted in 57 (72.2%), with a median (range) of 30 (3–411) days. Comparing patients without use of antibiotics and PPIs, consumption of both antibiotics and PPIs after CPE identification was associated with later clearance of CPE (hazard ratio, 0.35 [95% CI, 0.17–0.73], P=.005).

Concomitant use of antibiotics and PPIs prolonged duration of gastrointestinal colonization by CPE.

Infect Control Hosp Epidemiol 2016;1418–1425

To describe the epidemiology of complex surgical site infection (SSI) following commonly performed surgical procedures in community hospitals and to characterize trends of SSI prevalence rates over time for MRSA and other common pathogens

We prospectively collected SSI data at 29 community hospitals in the southeastern United States from 2008 through 2012. We determined the overall prevalence rates of SSI for commonly performed procedures during this 5-year study period. For each year of the study, we then calculated prevalence rates of SSI stratified by causative organism. We created log-binomial regression models to analyze trends of SSI prevalence over time for all pathogens combined and specifically for MRSA.

A total of 3,988 complex SSIs occurred following 532,694 procedures (prevalence rate, 0.7 infections per 100 procedures). SSIs occurred most frequently after small bowel surgery, peripheral vascular bypass surgery, and colon surgery. Staphylococcus aureus was the most common pathogen. The prevalence rate of SSI decreased from 0.76 infections per 100 procedures in 2008 to 0.69 infections per 100 procedures in 2012 (prevalence rate ratio [PRR], 0.90; 95% confidence interval [CI], 0.82–1.00). A more substantial decrease in MRSA SSI (PRR, 0.69; 95% CI, 0.54–0.89) was largely responsible for this overall trend.

The prevalence of MRSA SSI decreased from 2008 to 2012 in our network of community hospitals. This decrease in MRSA SSI prevalence led to an overall decrease in SSI prevalence over the study period.

Infect Control Hosp Epidemiol 2016;37:519–526

National hospital performance measures for C. difficile infection (CD) are available; comparing antibacterial use among performance levels can aid in identifying effective antimicrobial stewardship strategies to reduce CDI rates.

Hospital-level, cross-sectional analysis.

Hospital characteristics (ie, demographics, medications, patient mix) were obtained for 77 hospitals for 2013. Hospitals were assigned 1 of 3 levels of a CDI standardized infection ratio (SIR): ‘Worse than,’ ‘Better than,’ or ‘No different than’ a national benchmark. Analyses compared medication use (total and broad-spectrum antibacterials) for 3 metrics: days of therapy per 1,000 patient days; length of therapy; and proportion of patients receiving a medication across SIR levels. A multivariate, ordered-probit regression identified characteristics associated with SIR categories.

Regarding total average antimicrobial use per patient, there was a significant difference detected in mean length of therapy: ‘No different’ hospitals having the longest (4.93 days) versus ‘Worse’ (4.78 days) and ‘Better’ (4.43 days) (P<.01). ‘Better’ hospitals used fewer total antibacterials (693 days of therapy per 1,000 patient days) versus ‘No different’ (776 days) versus ‘Worse’ (777 days) (P<.05). The ‘Better’ hospitals used broad-spectrum antibacterials for a shorter average length of therapy (4.03 days) versus ‘No different’ (4.51 days) versus ‘Worse’ (4.38 days) (P<.05). ‘Better’ hospitals used fewer broad-spectrum antibacterials (310 days of therapy per 1,000 patient days) versus ‘No different’ (364 days) versus ‘Worse’ (349 days) (P<.05). Multivariate analysis revealed that the proportion of elderly patients and chemotherapy days of therapy per 1,000 patient days was significantly negatively associated with the SIR.

These findings have potential implications regarding the need to fully account for hospital patient mix when carrying out inter-hospital comparisons of CDI rates.

Infect Control Hosp Epidemiol 2016;37:909–915

To evaluate the new adult Centers for Disease Control and Prevention (CDC) ventilator-associated event (VAE) module in critically ill children and compare with the traditionally used CDC definition for ventilator-associated pneumonia (VAP).

Retrospective observational study of mechanically ventilated children in a pediatric intensive care unit in Greece January 1-December 31, 2011.

Assessment of new adult CDC VAE module including 3 definition tiers: ventilator-associated condition (VAC), infection-related VAC, and possible/probable ventilator-associated pneumonia (VAE-VAP); comparison with traditional CDC criteria for clinically defined pneumonia in mechanically ventilated children (PNEU-VAP). We recorded Pediatric Risk of Mortality score at admission (PRISM III), number of ventilator-days, and outcome.

Among 119 patients with mechanical ventilation (median [range] number of ventilator-days, 7 [1–183]), 19 patients experienced VAC. Criteria for VAE-VAP were fulfilled in 12 of 19 patients with VAC (63%). Children with either VAC or VAE-VAP were on ventilation more days than patients without these conditions (16.5 vs 5 d, P=.0006 and 18 vs 5 d, P<.001, respectively), whereas PRISM-III score was similar between them. Mortality was significant higher in patients with new VAE-VAP definition (50%), but not in patients with VAC (31.6%), than the patients without new VAE-VAP (14%, P=.007) or VAC (15%, P=.1), respectively. No significant association was found between PNEU-VAP and death. Incidences of PNEU-VAP and VAE-VAP were similar, but the agreement was poor.

VAE-VAP and PNEU-VAP found similar prevalence in critically ill children but with poor agreement. However, excess of death was significantly associated only with VAE-VAP.

Infect Control Hosp Epidemiol 2016:1–5

To determine the longitudinal changes in viral load of hepatitis B virus (HBV)–infected healthcare workers (HCWs) and its consequences for exclusion of infected HCWs performing exposure-prone procedures, various HBV DNA safety thresholds, and the frequency of monitoring.

Retrospective cohort study June 1, 1996–January 31, 2013.

In the Netherlands, chronically HBV-infected HCWs performing exposure-prone procedures are notified to the Committee for Prevention of Iatrogenic Hepatitis B. Of the 126 notified HCWs, 45 had 2 or more HBV DNA levels determined without antiviral therapy.

A time-to-event analysis for HBV-infected HCWs categorized in various viremia levels surpassing a HBV DNA threshold level of 1×105 copies/mL, above which exposure-prone procedures are not allowed in the Netherlands.

Fluctuations of HBV DNA in follow-up samples ranged from −5.4 to +2.2 log10 copies/mL. A high correlation was seen for each HBV DNA level with the 3 previous levels. In a time-to-event analysis, after 6 months 7.2%, 6.5%, and 14.3% of individuals had surpassed the threshold of 1×105 copies/mL for viral load categories 4.8×103 to 1.5×104; 1.5×104 to 4.0×104; and 4.0×104 to 1.0×105, respectively.

We propose standard retesting every 6 months, with more frequent retesting just below the high threshold value (1×105 copies/mL), and prolonging this standard interval to 1 year after 3 consecutive levels below the threshold in policies with lower safety thresholds (1×103 or 1×104 copies/mL).

Infect Control Hosp Epidemiol 2016;37:655–660

To determine the typical microbial bioburden (overall bacterial and multidrug-resistant organisms [MDROs]) on high-touch healthcare environmental surfaces after routine or terminal cleaning.

Prospective 2.5-year microbiological survey of large surface areas (>1,000 cm2).

MDRO contact-precaution rooms from 9 acute-care hospitals and 2 long-term care facilities in 4 states.

Samples from 166 rooms (113 routine cleaned and 53 terminal cleaned rooms).

Using a standard sponge-wipe sampling protocol, 2 composite samples were collected from each room; a third sample was collected from each Clostridium difficile room. Composite 1 included the TV remote, telephone, call button, and bed rails. Composite 2 included the room door handle, IV pole, and overbed table. Composite 3 included toileting surfaces. Total bacteria and MDROs (ie, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci [VRE], Acinetobacter baumannii, Klebsiella pneumoniae, and C. difficile) were quantified, confirmed, and tested for drug resistance.

The mean microbial bioburden and range from routine cleaned room composites were higher (2,700 colony-forming units [CFU]/100 cm2; ≤1–130,000 CFU/100 cm2) than from terminal cleaned room composites (353 CFU/100 cm2; ≤1–4,300 CFU/100 cm2). MDROs were recovered from 34% of routine cleaned room composites (range ≤1–13,000 CFU/100 cm2) and 17% of terminal cleaned room composites (≤1–524 CFU/100 cm2). MDROs were recovered from 40% of rooms; VRE was the most common (19%).

This multicenter bioburden summary provides a first step to determining microbial bioburden on healthcare surfaces, which may help provide a basis for developing standards to evaluate cleaning and disinfection as well as a framework for studies using an evidentiary hierarchy for environmental infection control.

Infect Control Hosp Epidemiol 2016;1426–1432

Measuring processes of care performance rates is an invaluable tool for quality improvement; however, collecting daily process measure data is time-consuming and burdensome.

To evaluate the accuracy of sampling strategies to estimate monthly compliance rates with ventilator-associated pneumonia prevention measures.

A total of 37 intensive care units affiliated with 29 hospitals participating in a 2-state 35-month ventilator-associated pneumonia prevention collaborative. Analysis was limited to 325 unit-months with complete data entry rates.

We calculated unit-month level actual and sample monthly compliance rates for 6 ventilator-associated pneumonia prevention measures, using 4 sampling strategies: sample 1 day per month, sample 1 day per week, sample 7 consecutive days per month, and sample 7 consecutive days per month plus additional consecutive days as necessary to obtain at least 30 ventilator-days for that month whenever possible. We compared sample versus actual rates using paired t test and χ2 test.

Mean sampling accuracy ranged 84%–97% for 1 day per month, 91%–98% for 1 day per week, 92%–98% for 7 consecutive days per month, and 96%–99% for 7 consecutive days with at least 30 days per month if possible. The most accurate sampling strategy was to sample 7 consecutive days with at least 30 ventilator-days per month if possible. With this strategy, sample rates were within 10% of actual rates in 88%–99% of unit-months and within 5% of actual rates in 74%–97% of unit-months.

Sampling process measures intermittently rather than continually can yield accurate estimates of process measure performance rates.

Infect Control Hosp Epidemiol 2016;37:1037–1043

The Surgical Care Improvement Project bundle emphasizes operative infection prevention practices. Despite implementing the Surgical Care Improvement Project bundle in 2008, spinal fusion surgical site infections (SF-SSI) continued to be prevalent for this low-volume, high-risk surgery.

To design a combined pre-, peri-, and postoperative bundle (PPPB) that would lead to sustained reductions in SF-SSI rates.

Quality improvement project, before-after trial with cost-effectiveness analysis.

Children’s hospital.

All spinal fusion patients, 2008–2015.

A multidisciplinary team developed the PPPB composed of Surgical Care Improvement Project elements plus improved wound care practices, nursing standard of care, dedicated nursing unit, dermatology assessment tool and consultation, nursing education tool using “teach back” technique, and a “Back Home” kit. SF-SSI rates were compared before (2008–2010) and after (2011-February 2015) implementation of PPPB. PPPB compliance was monitored.

A total of 224 SF surgeries were performed from 2008 to February 2015. Pre-PPPB analysis revealed median time to SF-SSI of 28 days, secondary to skin and bowel flora. Mean 3-year pre-PPPB SF-SSI rate per 100 SF surgeries was 8.2 (8/98) (2008: 13.3 [4/30], 2009: 2.7 [1/37], 2010: 9.7 [3/31]). Mean SF-SSI rate after PPPB was 2.4 (3/126) (January 2011-February 2015); there was a 71% reduction in mean SSI rate (P=.0695). No SF-SSI occurred in neuromuscular patients (P=.008) after PPPB. Compliance with PPPB elements has been 100%.

PPPB led to sustained improvement in SF-SSI rates over 50 months. The PPPB could be reproduced for other surgeries.

Infect Control Hosp Epidemiol 2016;37:527–534

To describe trends in the epidemiology of healthcare-associated Infections (HAIs) in pediatric/neonatal intensive care units (ICUs) and to evaluate risk factors and impact of multidrug resistance in children admitted to ICUs.

Multicenter, retrospective, cohort study with a nested case-control study conducted from January 1, 2010, through December 31, 2014.

Three tertiary care pediatric hospitals in Italy and Brazil with a total of 103 ICU beds.

Inclusion criteria were admission to ICU during the study period, age at onset less than 18 years, and microbiologically confirmed HAI.

A total of 538 HAIs in 454 children were included; 93.3% of patients had comorbidities. Bloodstream infections were the leading pattern (45.4%). The cumulative incidence of HAI was 3.6/100 ICU admissions and the crude 30-day fatality rate was 5.7/1,000 admissions. The most frequently isolated pathogens were Enterobacteriaceae, followed by Pseudomonas aeruginosa and Staphylococcus aureus. Forty-four percent of isolates were multidrug-resistant (MDR). Two multivariate logistic regressions were performed. Factors independently associated with an MDR-HAI were country, previous antibiotics, transplantation, major surgery, and colonization by an MDR strain. Factors independently associated with 30-day case fatality were country, previous transplantation, fungal infection, bloodstream infection, lower respiratory tract infection, and infection caused by MDR strains.

Infection control and prevention can limit the spread of MDR strains and improve outcomes. Targeted surveillance programs collecting neonatal and pediatric HAI/bloodstream infection data and outcomes would allow global benchmarking. The next step is to identify methods to monitor key HAIs and integrate these into affordable intervention programs.

Infect Control Hosp Epidemiol 2016;1–8

To study the effect of discontinuation of systematic surveillance for vancomycin-resistant Enterococcus (VRE) and contact isolation of colonized patients on the incidence of VRE bacteremia

A hematology-oncology unit with high prevalence of VRE colonization characterized by predominantly sporadic molecular epidemiology

Inpatients with hematologic malignancies and recipients of hematopoietic stem cell transplantation

The incidence of VRE bacteremia was measured prospectively during 2 different 3-year time periods; the first during active VRE surveillance and contact precautions and the second after discontinuation of these policies. We assessed the collateral impact of this policy change on the incidence of bacteremia due to methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile infection even though we maintained contact precautions for these organisms. Incidence of infectious events was measured as number of events per 1,000 patients days per month. Time series analysis was used to evaluate trends.

The incidence of VRE bacteremia remained stable after discontinuation of VRE surveillance and contact precautions. The incidence of MRSA bacteremia and Clostridium difficile infection for which we continued contact precautions also remained stable. Aggregated antibiotic utilization and nursing hours per patient days were similar between the 2 study periods.

Active surveillance and contact precautions for VRE colonization did not appear to prevent VRE bacteremia in patients with hematologic malignancies and recipients of hematopoietic stem cell transplantation with high prevalence of VRE characterized by predominantly sporadic molecular epidemiology.

Infect. Control Hosp. Epidemiol. 2016;37(4):398–403

To concomitantly determine the differential degrees of air and environmental contamination by Acinetobacter baumannii based on anatomic source of colonization and type of ICU layout (single-occupancy vs open layout).

Longitudinal prospective surveillance study of air and environmental surfaces in patient rooms.

A 1,500-bed public teaching hospital in Miami, Florida.

Consecutive A. baumannii–colonized patients admitted to our ICUs between October 2013 and February 2014.

Air and environmental surfaces of the rooms of A. baumannii–colonized patients were sampled daily for up to 10 days. Pulsed-field gel electrophoresis (PFGE) was used to type and match the matching air, environmental, and clinical A. baumannii isolates.

A total of 25 A. baumannii–colonized patients were identified during the study period; 17 were colonized in the respiratory tract and 8 were colonized in the rectum. In rooms with rectally colonized patients, 38.3% of air samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 13.1% of air samples were positive (P=.0001). In rooms with rectally colonized patients, 15.5% of environmental samples were positive for A. baumannii; in rooms of patients with respiratory colonization, 9.5% of environmental samples were positive (P=.02). The rates of air contamination in the open-layout and single-occupancy ICUs were 17.9% and 21.8%, respectively (P=.5). Environmental surfaces were positive in 9.5% of instances in open-layout ICUs versus 13.4% in single-occupancy ICUs (P=.09).

Air and environmental surface contaminations were significantly greater among rectally colonized patients; however, ICU layout did not influence the rate of contamination.

Infect Control Hosp Epidemiol 2016;37:777–781

To develop a probabilistic method for measuring central line–associated bloodstream infection (CLABSI) rates that reduces the variability associated with traditional, manual methods of applying CLABSI surveillance definitions.

Multicenter retrospective cohort study of bacteremia episodes among patients hospitalized in adult patient-care units; the study evaluated presence of CLABSI.

Hospitals that used SafetySurveillor software system (Premier) and who also reported to the Centers for Disease Control and Prevention’s National Healthcare Safety Network (NHSN).

Patients were identified from a stratified sample from all eligible blood culture isolates from all eligible hospital units to generate a final set with an equal distribution (ie, 20%) from each unit type. Units were divided a priori into 5 major groups: medical intensive care unit, surgical intensive care unit, medical-surgical intensive care unit, hematology unit, or general medical wards.

Episodes were reviewed by 2 experts, and a selection of discordant reviews were re-reviewed. Data were joined with NHSN data for hospitals for in-plan months. A predictive model was created; model performance was assessed using the c statistic in a validation set and comparison with NHSN reported rates for in-plan months.

A final model was created with predictors of CLABSI. The c statistic for the final model was 0.75 (0.68–0.80). Rates from regression modeling correlated better with expert review than NHSN-reported rates.

The use of a regression model based on the clinical characteristics of the bacteremia outperformed traditional infection preventionist surveillance compared with an expert-derived reference standard.

Infect. Control Hosp. Epidemiol. 2016;37(2):149–155

Case mix index (CMI) has been used as a facility-level indicator of patient disease severity. We sought to evaluate the potential for CMI to be used for risk adjustment of National Healthcare Safety Network (NHSN) healthcare-associated infection (HAI) data.

NHSN facility-wide laboratory-identified Clostridium difficile infection event data from 2012 were merged with the fiscal year 2012 Inpatient Prospective Payment System (IPPS) Impact file by CMS certification number (CCN) to obtain a CMI value for hospitals reporting to NHSN. Negative binomial regression was used to evaluate whether CMI was significantly associated with healthcare facility-onset (HO) CDI in univariate and multivariate analysis.

Among 1,468 acute care hospitals reporting CDI data to NHSN in 2012, 1,429 matched by CCN to a CMI value in the Impact file. CMI (median, 1.49; interquartile range, 1.36–1.66) was a significant predictor of HO CDI in univariate analysis (P<.0001). After controlling for community onset CDI prevalence rate, medical school affiliation, hospital size, and CDI test type use, CMI remained highly significant (P<.0001), with an increase of 0.1 point in CMI associated with a 3.4% increase in the HO CDI incidence rate.

CMI was a significant predictor of NHSN HO CDI incidence. Additional work to explore the feasibility of using CMI for risk adjustment of NHSN data is necessary.

Infect. Control Hosp. Epidemiol. 2015;37(1):19–25

Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated (“CRKP readmission”) potentially contribute to transmission of CRKP.

To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe).

Cohort study from December 24, 2011, through July 1, 2013.

Multicenter consortium of acute care hospitals in the Great Lakes region.

All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture.

All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models.

Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32–6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72–17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission.

Hospitalized patients with CRKP—specifically those with a history of malignancy—are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.

Infect. Control Hosp. Epidemiol. 2016;37(3):281–288