To characterize the microbial disruption indices of hospitalized patients to predict colonization with multidrug-resistant organisms (MDROs).

A cross-sectional survey of the fecal microbiome was conducted in a tertiary referral, acute-care hospital in Boston, Massachusetts.

The study population consisted of adult patients hospitalized in general medical/surgical wards.

Rectal swabs were obtained from patients within 48 hours of hospital admission and screened for MDRO colonization using conventional culture techniques. The V4 region of the 16S rRNA gene was sequenced to assess the fecal microbiome. Microbial diversity and composition, as well as the functional potential of the microbial communities present in fecal samples, were compared between patients with and without MDRO colonization.

A total of 44 patients were included in the study, of whom 11 (25%) were colonized with at least 1 MDRO. Reduced microbial diversity and high abundance of metabolic pathways associated with multidrug-resistance mechanisms characterized the fecal microbiome of patients colonized with MDRO at hospital admission.

Our data suggest that microbial disruption indices may be key to predicting MDRO colonization and could provide novel infection control approaches.

Infect Control Hosp Epidemiol 2017;38:1312–1318

The National Healthcare Safety Network (NHSN) catheter-associated urinary tract infection (CAUTI) definition was revised as of January 2015 to exclude funguria and lower bacteriuria levels. We evaluated the effect of the CAUTI definition change on NHSN-defined central-line–associated bloodstream infection (CLABSI) outcomes.

We compared CAUTI and CLABSI NHSN-defined outcomes for calendar years 2014 and 2015 in the adult intensive care units (ICUs) of a single large health system. Changes in the event rates, the associated organisms, and the standardized infection ratio (SIR) were evaluated.

The study included 137 adult ICUs from 65 hospitals. The CAUTI SIR dropped from 1.04 in 2014 to 0.58 in 2015 (−44.2%), while the CLABSI SIR increased from 0.36 in 2014 to 0.47 in 2015 (+30.6%). CAUTI rates dropped 44.8% from 2.09 to 1.15 events per 1,000 device days (P<.001). Gram-positive–associated CAUTI rates dropped 36.7% from 0.34 to 0.22 per 1,000 device days (P=.007). CLABSI rates increased 27.1% from 0.71 to 0.90 per 1,000 device days (P=.027). Candida-associated CLABSI increased by 91.1% from 0.104 to 0.198 per 1,000 device days (P=.012), and Enterococcus-associated CLABSI increased by 121.6% from 0.071 to 0.16 per 1,000 device days (P=.008).

The revised CAUTI definition led to a large reduction in CAUTI rates and, in turn, an increase in candidemia and enterococcemia cases classified as CLABSI events. These findings have important implications on the perceived successes or failures to eliminate both infections.

Infect Control Hosp Epidemiol 2017;38:685–689

To examine variation in antibiotic coverage and detection of resistant pathogens in community-onset pneumonia.

Cross-sectional study.

A total of 128 hospitals in the Veterans Affairs health system.

Hospitalizations with a principal diagnosis of pneumonia from 2009 through 2010.

We examined proportions of hospitalizations with empiric antibiotic coverage for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAER) and with initial detection in blood or respiratory cultures. We compared lowest- versus highest-decile hospitals, and we estimated adjusted probabilities (AP) for patient- and hospital-level factors predicting coverage and detection using hierarchical regression modeling.

Among 38,473 hospitalizations, empiric coverage varied widely across hospitals (MRSA lowest vs highest, 8.2% vs 42.0%; PAER lowest vs highest, 13.9% vs 44.4%). Detection rates also varied (MRSA lowest vs highest, 0.5% vs 3.6%; PAER lowest vs highest, 0.6% vs 3.7%). Whereas coverage was greatest among patients with recent hospitalizations (AP for anti-MRSA, 54%; AP for anti-PAER, 59%) and long-term care (AP for anti-MRSA, 60%; AP for anti-PAER, 66%), detection was greatest in patients with a previous history of a positive culture (AP for MRSA, 7.9%; AP for PAER, 11.9%) and in hospitals with a high prevalence of the organism in pneumonia (AP for MRSA, 3.9%; AP for PAER, 3.2%). Low hospital complexity and rural setting were strong negative predictors of coverage but not of detection.

Hospitals demonstrated widespread variation in both coverage and detection of MRSA and PAER, but probability of coverage correlated poorly with probability of detection. Factors associated with empiric coverage (eg, healthcare exposure) were different from those associated with detection (eg, microbiology history). Providing microbiology data during empiric antibiotic decision making could better align coverage to risk for resistant pathogens and could promote more judicious use of broad-spectrum antibiotics.

Infect Control Hosp Epidemiol 2017;38:937–944

Burn patients are particularly vulnerable to infection, and an estimated half of all burn deaths are due to infections. This study explored risk factors for healthcare-associated infections (HAIs) in adult burn patients.

Retrospective cohort study.

Tertiary-care burn center.

Adults (≥18 years old) admitted with burn injury for at least 2 days between 2004 and 2013.

HAIs were determined in real-time by infection preventionists using Centers for Disease Control and Prevention criteria. Multivariable Cox proportional hazards regression was used to estimate the direct effect of each risk factor on time to HAI, with inverse probability of censor weights to address potentially informative censoring. Effect measure modification by burn size was also assessed.

Overall, 4,426 patients met inclusion criteria, and 349 (7.9%) patients had at least 1 HAI within 60 days of admission. Compared to <5% total body surface area (TBSA), patients with 5%–10% TBSA were almost 3 times as likely to acquire an HAI (hazard ratio [HR], 2.92; 95% CI, 1.63–5.23); patients with 10%–20% TBSA were >6 times as likely to acquire an HAI (HR, 6.38; 95% CI, 3.64–11.17); and patients with >20% TBSA were >10 times as likely to acquire an HAI (HR, 10.33; 95% CI, 5.74–18.60). Patients with inhalational injury were 1.5 times as likely to acquire an HAI (HR, 1.61; 95% CI, 1.17–2.22). The effect of inhalational injury (P=.09) appeared to be larger among patients with ≤20% TBSA.

Larger burns and inhalational injury were associated with increased incidence of HAIs. Future research should use these risk factors to identify potential interventions.

Infect Control Hosp Epidemiol 2017;38:1441–1448

To examine knowledge and attitudes about influenza vaccination and infection prevention practices among healthcare personnel (HCP) in a long-term-care (LTC) setting.

Knowledge, attitudes, and practices (KAP) survey.

An LTC facility in St Louis, Missouri.

All HCP working at the LTC facility were eligible to participate, regardless of department or position. Of 170 full- and part-time HCP working at the facility, 73 completed the survey, a 42.9% response rate.

Most HCP agreed that respiratory viral infections were serious and that hand hygiene and face mask use were protective. However, only 46% could describe the correct transmission-based precautions for an influenza patient. Correctly answering infection prevention knowledge questions did not vary by years of experience but did vary for HCP with more direct patient contact versus less patient contact. Furthermore, 42% of respondents reported working while sick, and 56% reported that their coworkers did. In addition, 54% reported that facility policies made staying home while ill difficult. Some respondents expressed concerns about the safety (22%) and effectiveness (27%) of the influenza vaccine, and 28% of respondents stated that they would not get the influenza vaccine if it was not required.

This survey of staff in an LTC facility identified several areas for policy improvement, particularly sick leave, as well as potential targets for interventions to improve infection prevention knowledge and to address HCP concerns about influenza vaccination to improve HCP vaccination rates in LTCs.

Infect Control Hosp Epidemiol 2017;38:1449–1456

To assess the burden of bloodstream infections (BSIs) among pediatric hematology-oncology (PHO) inpatients, to propose a comprehensive, all-BSI tracking approach, and to discuss how such an approach helps better inform within-center and across-center differences in CLABSI rate

Prospective cohort study

US multicenter, quality-improvement, BSI prevention network

PHO centers across the United States who agreed to follow a standardized central-line–maintenance care bundle and track all BSI events and central-line days every month.

Infections were categorized as CLABSI (stratified by mucosal barrier injury–related, laboratory-confirmed BSI [MBI-LCBI] versus non–MBI-LCBI) and secondary BSI, using National Healthcare Safety Network (NHSN) definitions. Single positive blood cultures (SPBCs) with NHSN defined common commensals were also tracked.

Between 2013 and 2015, 34 PHO centers reported 1,110 BSIs. Among them, 708 (63.8%) were CLABSIs, 170 (15.3%) were secondary BSIs, and 232 (20.9%) were SPBCs. Most SPBCs (75%) occurred in patients with profound neutropenia; 22% of SPBCs were viridans group streptococci. Among the CLABSIs, 51% were MBI-LCBI. Excluding SPBCs, CLABSI rates were higher (88% vs 77%) and secondary BSI rates were lower (12% vs 23%) after the NHSN updated the definition of secondary BSI (P<.001). Preliminary analyses showed across-center differences in CLABSI versus secondary BSI and between SPBC and CLABSI versus non-CLABSI rates.

Tracking all BSIs, not just CLABSIs in PHO patients, is a patient-centered, clinically relevant approach that could help better assess across-center and within-center differences in infection rates, including CLABSI. This approach enables informed decision making by healthcare providers, payors, and the public.

Infect Control Hosp Epidemiol 2017;38:690–696

To describe the effect of universal methicillin-resistant Staphylococcus aureus (MRSA) decolonization therapy in a large intensive care unit (ICU) on the rates of MRSA cases and acquisitions in a UK hospital.

Descriptive study.

University Hospitals Birmingham (UHB) NHS Foundation Trust is a tertiary referral teaching hospital in Birmingham, United Kingdom, that provides clinical services to nearly 1 million patients every year.

A break-point time series analysis and kernel regression models were used to detect significant changes in the cumulative monthly numbers of MRSA bacteremia cases and acquisitions from April 2013 to August 2016 across the UHB system.

Prior to 2014, all ICU patients at UHB received universal MRSA decolonization therapy. In August 2014, UHB discontinued the use of universal decolonization due to published reports in the United Kingdom detailing the limited usefulness and cost-effectiveness of such an intervention. Break-point time series analysis of MRSA acquisition and bacteremia data indicated that break points were associated with the discontinuation and subsequent reintroduction of universal decolonization. Kernel regression models indicated a significant increase (P<.001) in MRSA acquisitions and bacteremia cases across UHB during the period without universal decolonization.

We suggest that routine decolonization for MRSA in a large ICU setting is an effective strategy to reduce the spread and incidence of MRSA across the whole hospital.

Infect Control Hosp Epidemiol 2017;38:430–435

To determine the origin of grouped cases of Pneumocystis pneumonia in solid-organ transplant recipients at our institution.

A case series with clinical examinations, genotyping, and an epidemiological survey.

A university hospital in France.

We report 12 solid-organ transplant recipients with successive cases of Pneumocystis pneumonia that occurred over 3 years; 10 of these cases occurred in a single year.

We used molecular typing of P. jirovecii strains by multilocus sequence typing and clinical epidemiological survey to determine potential dates and places of transmission.

Between May 2014 and March 2015, 10 solid-organ transplant recipients (5 kidney transplants, 4 heart transplants, and 1 lung transplant) presented with Pneumocystis pneumonia. Molecular genotyping revealed the same P. jirovecii strain in at least 6 patients. This Pneumocystis strain was not identified in control patients (ie, nontransplant patients presenting with pulmonary pneumocystosis) during this period. The epidemiological survey guided by sequencing results provided information on the probable or possible dates and places of contamination for 5 of these patients. The mobile infectious diseases unit played a coordination role in the clinical management (adaptation of the local guidelines) and epidemiological survey.

Our cardiac and kidney transplant units experienced grouped cases of pulmonary pneumocystosis. Genotyping and epidemiological surveying results suggested interhuman contamination, which was quickly eliminated thanks to multidisciplinary coordination.

Infect Control Hosp Epidemiol 2017;38:179–185

Considerable efforts have been dedicated to developing strategies to prevent and treat recurrent Clostridium difficile infection (rCDI); however, evidence of the impact of rCDI on patient healthcare utilization and outcomes is limited.

To compare healthcare utilization and 1-year mortality among adults who had rCDI, nonrecurrent CDI, or no CDI.

We performed a nested case-control study among adult Kaiser Foundation Health Plan members from September 1, 2001, through December 31, 2013. We identified CDI through the presence of a positive laboratory test result and divided patients into 3 groups: patients with rCDI, defined as CDI in the 14–57 days after initial CDI; patients with nonrecurrent CDI; and patients who never had CDI. We conducted 3 matched comparisons: (1) rCDI vs no CDI; (2) rCDI vs nonrecurrent CDI; (3) nonrecurrent CDI vs no CDI. We followed patients for 1 year and compared healthcare utilization between groups, after matching patients on age, sex, and comorbidity.

We found that patients with rCDI consistently have substantially higher levels of healthcare utilization in various settings and greater 1-year mortality risk than both patients who had nonrecurrent CDI and patients who never had CDI.

Patients who develop an initial CDI are generally characterized by excess underlying, severe illness and utilization. However, patients with rCDI experience even greater adverse consequences of their disease than patients who do not experience rCDI. Our results further support the need for continued emphasis on identifying and using novel approaches to prevent and treat rCDI.

Infect Control Hosp Epidemiol. 2016;1–8

Although the hands of healthcare workers (HCWs) are implicated in most episodes of healthcare-associated infections, the correlation between hand contamination and the likelihood of cross-transmission remains unknown.

We conducted a laboratory-based study involving pairs of HCWs. The hands of a HCW (transmitter) were contaminated with Escherichia coli ATCC 10536 before holding hands with another HCW (host) for 1 minute. Meanwhile, the unheld hand of the transmitter was sampled. Afterward, the host’s held hand was also sampled. Each experiment consisted of 4 trials with increasing concentrations of E. coli (103–106 colony-forming units [cfu]/mL). The primary outcome was the likelihood of transmission of at least 1 cfu from transmitter to host. We used a mixed logistic regression model with a random effect on the subject to assess the association between transmission and bacterial count on the transmitter’s hands.

In total, 6 HCWs performed 30 experiments and 120 trials. The bacterial counts recovered from host hands were directly associated with the bacterial counts on transmitter hands (P<.001). The probability of cross-transmission was 8.22 higher (95% confidence interval [CI], 0.98–68.8) when transmitter hand bacterial count was >1 and ≤3 log10 cfu compared to ≤1 log10. When transmitter contamination was <1 log10 cfu, no cross-transmission was detected.

There is a direct relationship between the bacterial burden on HCWs hands and the likelihood of cross-transmission. Under the described conditions, at least 1 log10 cfu must be present on HCW hands to be potentially transmitted. Further studies are needed at the low contamination range.

Infect Control Hosp Epidemiol 2017;38:553–558

We aimed to ascertain the factors associated with lack of isolation precautions (IP) in patients infected or colonized by third-generation cephalosporin-resistant Enterobacteriaceae (3GCR-E) and methicillin-resistant Staphylococcus aureus (MRSA) in hospital settings.

Prospective surveillance and audit of practices.

The study included 4 university hospitals in Lyon, France.

All patients hospitalized between April and June in 2013 and 2015 were included. Case patients had ≥1 clinical sample positive for MRSA and/or 3GCR-E.

Factors associated with the lack of IP implementation were identified using multivariate logistic regression. The incidence of MDRO infections was expressed per 10,000 patient days.

Overall, 57,222 patients accounting for 192,234 patient days of hospitalization were included, and 635 (1.1%) MDRO cases were identified. MRSA incidence was 2.5 per 10,000 patient days (95% confidence interval [95% CI], 2.1–3.0) and 3GCR-E incidence was 10.1 per 10,000 patient days (95% CI, 9.2–11.0), with no crude difference between 2013 and 2015 (P=.15 and P=.11, respectively). Among 3GCR-E, the main species were Escherichia coli (43.8%) and Klebsiella pneumoniae (31.0%). Isolation precautions were implemented in 78.5% of cases. Lack of IP implementation was independently associated with patient age, year, specialty, hospital, colonization compared with infection, and lack of medical prescription for IPs (adjusted odds ratio, 17.4; 95% CI, 8.5–35.8; P<.001).

MRSA and 3GCR-E infections and/or colonizations are frequent in healthcare settings, and IPs are implemented in most cases. When IPs are lacking, the main factor is the absence of medical prescription for IPs, underscoring the need for alerts to physicians by the microbiological laboratory and/or the infection control team.

Infect Control Hosp Epidemiol 2017;38:1188–1195

Simulation models have been used to investigate the impact of hand hygiene on methicillin-resistant Staphylococcus aureus (MRSA) transmission within the healthcare setting, but they have been limited by their ability to accurately model complex patient–provider interactions.

Using a network-based modeling approach, we created a simulated neonatal intensive care unit (NICU) representing the potential for per-hour infant–infant MRSA transmission via the healthcare worker resulting in subsequent colonization. The starting prevalence of MRSA colonized infants varied from 2% to 8%. Hand hygiene ranged from 0% (none) to 100% (theoretical maximum), with an expected effectiveness of 88% inferred from literature.

Based on empiric care provided within a 1-hour period, the mean number of infant–infant MRSA transmissible opportunities per hour was 1.3. Compared to no hand hygiene and averaged across all initial colonization states, colonization was reduced by approximately 29%, 51%, 67%, 80%, and 86% for the respective levels of hygiene: 24%, 48%, 68%, 88%, and 100%. Preterm infants had a 61% increase in MRSA colonization, and mechanically ventilated infants had a 27% increase.

Even under optimal hygiene conditions, horizontal transmission of MRSA is possible. Additional prevention paradigms should focus on the most acute patients because they are at greatest risk.

Infect Control Hosp Epidemiol 2017;38:945–952

Mortality associated with infections caused by carbapenem-resistant Enterobacteriaceae (CRE) is higher than mortality due to carbapenem-sensitive pathogens.

To examine the association between mortality from bacteremia caused by carbapenem-resistant (CRKP) and carbapenem-sensitive Klebsiella pneumoniae (CSKP) and to assess the impact of appropriate initial antibiotic therapy (IAT) on mortality.

Systematic review and meta-analysis

We searched MEDLINE, EMBASE, CINAHL, and Wiley Cochrane databases through August 31, 2016, for observational studies reporting mortality among adult patients with CRKP and CSKP bacteremia. Search terms were related to Klebsiella, carbapenem-resistance, and infection. Studies including fewer than 10 patients per group were excluded. A random-effects model and meta-regression were used to assess the relationship between carbapenem-resistance, appropriateness of IAT, and mortality.

Mortality was higher in patients who had CRKP bacteremia than in patients with CSKP bacteremia (15 studies; 1,019 CRKP and 1,148 CSKP patients; unadjusted odds ratio [OR], 2.2; 95% confidence interval [CI], 1.8–2.6; I2=0). Mortality was lower in patients with appropriate IAT than in those without appropriate IAT (7 studies; 658 patients; unadjusted OR, 0.5; 95% CI, 0.3–0.8; I2=36%). CRKP patients (11 studies; 1,326 patients; 8-year period) were consistently less likely to receive appropriate IAT (unadjusted OR, 0.5; 95% CI, 0.3–0.7; I2=43%). Our meta-regression analysis identified a significant association between the difference in appropriate IAT and mortality (OR per 10% difference in IAT, 1.3; 95% CI, 1.0–1.6).

Appropriateness of IAT is an important contributor to the observed difference in mortality between patients with CRKP bacteremia and patients with CSKP bacteremia.

Infect Control Hosp Epidemiol 2017;38:1319–1328

While a direct relation between hospital construction and concomitant infection rates has been clearly established, few data are available regarding the environmental decontamination effects of renovation in which surfaces are replaced and regarding subsequent infection incidence.

Retrospective clinical study with vancomycin-resistant Enterococcus (VRE) molecular strain typing and environmental cultures.

A regional referral center for acute leukemia and hematopoietic stem-cell transplantation.

Overall, 536 consecutive hospital admissions for newly diagnosed acute leukemia or a first autologous or allogeneic stem-cell transplantation were reviewed.

During 2009–2010, our unit underwent complete remodeling including replacement of all surfaces. We assessed the effects of this construction on the incidence of hospital-acquired VRE colonization before, during, and after the renovation.

We observed a sharp decrease in VRE colonization rates (hazard ratio, <0.23; 95% confidence interval, 0.18–0.44; P<.0001) during the first year after the renovation, with a return to near baseline rates thereafter. The known risk factors for VRE colonization appeared to be stable over the study interval. Environmental cultures outside of patient rooms revealed several contaminated areas that are commonly touched by unit personnel. Multilocus sequence typing of VRE isolates that were cryopreserved over the study interval showed that dominant strains prior to construction disappeared and were replaced by other strains after the renovation.

Unit reconstruction interrupted endemic transmission of VRE, which resumed with novel strains upon reopening. Contamination of environmental surfaces and shared equipment may play an important role in endemic transmission of VRE.

Infect Control Hosp Epidemiol 2017;38:1055–1061

Orthopedic procedures are an important focus in efforts to reduce surgical site infections (SSIs). In 2008, the Centers for Medicare and Medicaid (CMS) stopped reimbursements for additional charges associated with serious hospital-acquired conditions, including SSI following certain orthopedic procedures. We aimed to evaluate the CMS policy’s effect on rates of targeted orthopedic SSIs among the Medicare population.

We examined SSI rates following orthopedic procedures among the Medicare population before and after policy implementation compared to a similarly aged control group. Using the Nationwide Inpatient Sample database for 2000–2013, we estimated rate ratios (RRs) of orthopedic SSIs among Medicare and non-Medicare patients using a difference-in-differences approach.

Following policy implementation, SSIs significantly decreased among both the Medicare and non-Medicare populations (RR, 0.7; 95% confidence interval [CI], 0.6–0.8) and RR, 0.8l; 95% CI, 0.7–0.9), respectively. However, the estimated decrease among the Medicare population was not significantly greater than the decrease among the control population (RR, 0.9; 95% CI, 0.8–1.1).

While SSI rates decreased significantly following the implementation of the CMS nonpayment policy, this trend was not associated with policy intervention but rather larger secular trends that likely contributed to decreasing SSI rates over time.

Infect Control Hosp Epidemiol 2017;38:817–822

To define the scope of an outbreak of Legionnaires’ disease (LD), to identify the source, and to stop transmission.

Epidemiologic investigation of an LD outbreak among patients and a visitor exposed to a newly constructed hematology-oncology unit.

An LD case was defined as radiographically confirmed pneumonia in a person with positive urinary antigen testing and/or respiratory culture for Legionella and exposure to the hematology-oncology unit after February 20, 2014. Cases were classified as definitely or probably healthcare-associated based on whether they were exposed to the unit for all or part of the incubation period (2–10 days). We conducted an environmental assessment and collected water samples for culture. Clinical and environmental isolates were compared by monoclonal antibody (MAb) and sequence-based typing.

Over a 12-week period, 10 cases were identified, including 6 definite and 4 probable cases. Environmental sampling revealed Legionella pneumophila serogroup 1 (Lp1) in the potable water at 9 of 10 unit sites (90%), including all patient rooms tested. The 3 clinical isolates were identical to environmental isolates from the unit (MAb2-positive, sequence type ST36). No cases occurred with exposure after the implementation of water restrictions followed by point-of-use filters.

Contamination of the unit’s potable water system with Lp1 strain ST36 was the likely source of this outbreak. Healthcare providers should routinely test patients who develop pneumonia at least 2 days after hospital admission for LD. A single case of LD that is definitely healthcare associated should prompt a full investigation.

Infect Control Hosp Epidemiol 2017;38:306–313

Catheter-associated urinary tract infections (CAUTIs) are among the most common hospital-acquired infections (HAIs). Reducing CAUTI rates has become a major focus of attention due to increasing public health concerns and reimbursement implications.

To implement and describe a multifaceted intervention to decrease CAUTIs in our ICUs with an emphasis on indications for obtaining a urine culture.

A project team composed of all critical care disciplines was assembled to address an institutional goal of decreasing CAUTIs. Interventions implemented between year 1 and year 2 included protocols recommended by the Centers for Disease Control and Prevention for placement, maintenance, and removal of catheters. Leaders from all critical care disciplines agreed to align routine culturing practice with American College of Critical Care Medicine (ACCCM) and Infectious Disease Society of America (IDSA) guidelines for evaluating a fever in a critically ill patient. Surveillance data for CAUTI and hospital-acquired bloodstream infection (HABSI) were recorded prospectively according to National Healthcare Safety Network (NHSN) protocols. Device utilization ratios (DURs), rates of CAUTI, HABSI, and urine cultures were calculated and compared.

The CAUTI rate decreased from 3.0 per 1,000 catheter days in 2013 to 1.9 in 2014. The DUR was 0.7 in 2013 and 0.68 in 2014. The HABSI rates per 1,000 patient days decreased from 2.8 in 2013 to 2.4 in 2014.

Effectively reducing ICU CAUTI rates requires a multifaceted and collaborative approach; stewardship of culturing was a key and safe component of our successful reduction efforts.

Infect Control Hosp Epidemiol 2017;38:186–188

To compare different techniques of endoscope sampling to assess residual bacterial contamination.

Diagnostic study.

The endoscopy unit of an 1,100-bed university hospital performing ~13,000 endoscopic procedures annually.

In total, 4 sampling techniques, combining flushing fluid with or without a commercial endoscope brush, were compared in an endoscope model. Based on these results, sterile physiological saline flushing with or without PULL THRU brush was selected for evaluation on 40 flexible endoscopes by adenosine triphosphate (ATP) measurement and bacterial culture. Acceptance criteria from the French National guideline (<25 colony-forming units [CFU] per endoscope and absence of indicator microorganisms) were used as part of the evaluation.

On biofilm-coated PTFE tubes, physiological saline in combination with a PULL THRU brush generated higher mean ATP values (2,579 relative light units [RLU]) compared with saline alone (1,436 RLU; P=.047). In the endoscope samples, culture yield using saline plus the PULL THRU (mean, 43 CFU; range, 1–400 CFU) was significantly higher than that of saline alone (mean, 17 CFU; range, 0–500 CFU; P<.001). In samples obtained using the saline+PULL THRU brush method, ATP values of samples classified as unacceptable were significantly higher than those of samples classified as acceptable (P=.001).

Physiological saline flushing combined with PULL THRU brush to sample endoscopes generated higher ATP values and increased the yield of microbial surveillance culture. Consequently, the acceptance rate of endoscopes based on a defined CFU limit was significantly lower when the saline+PULL THRU method was used instead of saline alone.

Infect Control Hosp Epidemiol 2017;38:1062–1069

Multistate and competing risks models have become an established and adequate tool with which to quantify determinants and consequences of nosocomial infections. In this tutorial article, we explain and demonstrate the basics of these models to a broader audience of professionals in health care, infection control, and hospital epidemiology.

Using a publicly available data set from a cohort study of intensive care unit patients, we show how hospital infection data can be displayed and explored graphically and how simple formulas are derived under some simplified assumptions for illustrating the basic ideas behind multistate models. Only a few simply accessible values (event counts and patient days) and a pocket calculator are needed to reveal basic insights into cumulative risk and clinical outcomes of nosocomial infection in terms of mortality and length of stay.

We show how to use these values to perform basic multistate analyses in own data or to correct biased estimates in published data, as these values are often reported. We also show relationships between multistate-based hazard ratios and odds ratios, which are derived from the popular logistic regression model.

No sophisticated statistical software is required to apply a basic multistate model and to avoid typical pitfalls such as time-dependent or competing-risks bias.

Infect Control Hosp Epidemiol 2017;38:953–959

To determine the source of a healthcare-associated outbreak of Pantoea agglomerans bloodstream infections.

Epidemiologic investigation of the outbreak.

Oncology clinic (clinic A).

Cases were defined as Pantoea isolation from blood or catheter tip cultures of clinic A patients during July 2012–May 2013. Clinic A medical charts and laboratory records were reviewed; infection prevention practices and the facility’s water system were evaluated. Environmental samples were collected for culture. Clinical and environmental P. agglomerans isolates were compared using pulsed-field gel electrophoresis.

Twelve cases were identified; median (range) age was 65 (41–78) years. All patients had malignant tumors and had received infusions at clinic A. Deficiencies in parenteral medication preparation and handling were identified (eg, placing infusates near sinks with potential for splash-back contamination). Facility inspection revealed substantial dead-end water piping and inadequate chlorine residual in tap water from multiple sinks, including the pharmacy clean room sink. P. agglomerans was isolated from composite surface swabs of 7 sinks and an ice machine; the pharmacy clean room sink isolate was indistinguishable by pulsed-field gel electrophoresis from 7 of 9 available patient isolates.

Exposure of locally prepared infusates to a contaminated pharmacy sink caused the outbreak. Improvements in parenteral medication preparation, including moving chemotherapy preparation offsite, along with terminal sink cleaning and water system remediation ended the outbreak. Greater awareness of recommended medication preparation and handling practices as well as further efforts to better define the contribution of contaminated sinks and plumbing deficiencies to healthcare-associated infections are needed.

Infect Control Hosp Epidemiol 2017;38:314–319