Clostridium difficile spores persist in hospital environments for an extended period. We evaluated whether admission to a room previously occupied by a patient with C. difficile infection (CDI) increased the risk of acquiring CDI.

Retrospective cohort study.

Medical intensive care unit (ICU) at a tertiary care hospital.

Patients admitted from January 1, 2005, through June 30, 2006, were evaluated for a diagnosis of CDI 48 hours after ICU admission and within 30 days after ICU discharge. Medical, ICU, and pharmacy records were reviewed for other CDI risk factors. Admitted patients who did develop CDI were compared with admitted patients who did not.

Among 1,844 patients admitted to the ICU, 134 CDI cases were identified. After exclusions, 1,770 admitted patients remained for analysis. Of the patients who acquired CDI after admission to the ICU, 4.6% had a prior occupant without CDI, whereas 11.0% had a prior occupant with CDI (P = .002). The effect of room on CDI acquisition remained a significant risk factor (P = .008) when Kaplan-Meier curves were used. The prior occupant's CDI status remained significant (P = .01; hazard ratio, 2.35) when controlling for the current patient's age, Acute Physiology and Chronic Health Evaluation III score, exposure to proton pump inhibitors, and antibiotic use.

A prior room occupant with CDI is a significant risk factor for CDI acquisition, independent of established CDI risk factors. These findings have implications for room placement and hospital design.

To identify patient-care practices related to an increased prevalence of hepatitis C virus (HCV) infection among chronic hemodialysis patients.

Survey.

Chronic hemodialysis facilities in the United States.

Equal-probability 2-stage cluster sampling was used to select 87 facilities from all Medicare-approved providers treating 30–150 patients; 53 facilities and 2,933 of 3,680 eligible patients agreed to participate.

Patients were tested for HCV antibody and HCV RNA. Data on patient-care practices were collected using direct observation.

The overall prevalence of HCV infection was 9.9% (95% confidence interval [CI], 8.2%–11.6%); only 2 of 294 HCV-positive patients were detected solely by HCV RNA testing. After adjusting for non-dialysis-related HCV risk factors, patient-care practices independently associated with a higher prevalence of HCV infection included reusing priming receptacles without disinfection (odds ratio [OR], 2.3 [95% CI, 1.4–3.9]), handling blood specimens adjacent to medications and clean supplies (OR, 2.2 [95% CI, 1.3–3.6]), and using mobile carts to deliver injectable medications (OR, 1.7 [95% CI, 1.0–2.8]). Independently related facility covariates were at least 10% patient HCV infection prevalence (OR, 3.0 [95% CI, 1.8–5.2]), patient-to-staff ratio of at least 7: 1 (OR, 2.4 [95% CI, 1.4–4.1]), and treatment duration of at least 2 years (OR, 2.4 [95% CI, 1.3–4.4]).

This study provides the first epidemiologic evidence of associations between specific patient-care practices and higher HCV infection prevalence among hemodialysis patients. Staff should review practices to ensure that hemodialysis-specific infection control practices are being implemented, especially handling clean and contaminated items in separate areas, reusing items only if disinfected, and prohibiting mobile medication and clean supply carts within treatment areas.

The multicenter, cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was performed in 18 U.S. adult intensive care units (ICUs). It evaluated the effectiveness of infection control strategies to reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission.

Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis.

Of 5,512 ICU patient admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a nares sample culture result that was positive for MRSA. A total of 210 (34%) of 626 available isolates were selected for molecular typing by weighted random sampling. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USAIOO clone, 26 (12%) were USA300, 12 (6%) were USA500, 8 (4%) were USA800, and 17 (8%) were other MRSA genotypes. In a multivariate analysis, patients who were colonized with a CA-MRSA genotype (USA300, USA400, or USA1000) were less likely to have been hospitalized during the previous 12 months (PR [prevalence ratio], 0.39 [95% confidence interval (CI), 0.21-0.73]) and were less likely to be older (PR, 0.97 [95% CI, 0.95-0.98] per year) compared with patients who were colonized with a healthcare-associated (HA)-MRSA genotype.

CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the United States. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community.

To estimate the proportion of healthcare-associated infections (HAIs) in US hospitals that are “reasonably preventable,” along with their related mortality and costs.

To estimate preventability of catheter-associated bloodstream infections (CABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), and ventilator-associated pneumonia (VAP), we used a federally sponsored systematic review of interventions to reduce HAIs. Ranges of preventability included the lowest and highest risk reductions reported by US studies of “moderate” to “good” quality published in the last 10 years. We used the most recently published national data to determine the annual incidence of HAIs and associated mortality. To estimate incremental cost of HAIs, we performed a systematic review, which included costs from studies in general US patient populations. To calculate ranges for the annual number of preventable infections and deaths and annual costs, we multiplied our infection, mortality, and cost figures with our ranges of preventability for each HAI.

AS many as 65%–70% of cases of CABSI and CAUTI and 55% of cases of VAP and SSI may be preventable with current evidence-based strategies. CAUTI may be the most preventable HAI. CABSI has the highest number of preventable deaths, followed by VAP. CABSI also has the highest cost impact; costs due to preventable cases of VAP, CAUTI, and SSI are likely less.

Our findings suggest that 100% prevention of HAIs may not be attainable with current evidence-based prevention strategies; however, comprehensive implementation of such strategies could prevent hundreds of thousands of HAIs and save tens of thousands of lives and billions of dollars.

To evaluate two different methods of measuring catheter-associated urinary tract infection (CAUTI) rates in the setting of a quality improvement initiative aimed at reducing device utilization.

Comparison of CAUTI measurements in the context of a before-after trial of acute care adult admissions to a multicentered healthcare system.

CAUTIs were identified with an automated surveillance system, and device-days were measured through an electronic health record. Traditional surveillance measures of CAUTI rates per 1,000 device-days (R1) were compared with CAUTI rates per 10,000 patient-days (R2) before (T1) and after (T2) an intervention aimed at reducing catheter utilization.

The device-utilization ratio declined from 0.36 to 0.28 between T1 and T2 (P< .001), while infection rates were significantly lower when measured by R2 (28.2 vs 23.2, P = .02). When measured by R1, however, infection rates trended upward by 6% (7.79 vs. 8.28, P = .47), and at the nursing unit level, reduction in device utilization was significantly associated with increases in infection rate.

The widely accepted practice of using device-days as a method of risk adjustment to calculate device-associated infection rates may mask the impact of a successful quality improvement program and reward programs not actively engaged in reducing device usage.

To determine the ability of a mobile UV light unit to reduce bacterial contamination of environmental surfaces in patient rooms.

An automated mobile UV light unit that emits UV-C light was placed in 25 patient rooms after patient discharge and operated using a 1- or 2-stage procedure. Aerobic colony counts were calculated for each of 5 standardized high-touch surfaces in the rooms before and after UV light decontamination (UVLD). Clostridium difficile spore log reductions achieved were determined using a modification of the ASTM (American Society for Testing and Materials) International E2197 quantitative disk carrier test method. In-room ozone concentrations during UVLD were measured.

For the 1-stage procedure, mean aerobic colony counts for the 5 high-touch surfaces ranged from 10.6 to 98.2 colony-forming units (CFUs) per Dey/Engley (D/E) plate before UVLD and from 0.3 to 24.0 CFUs per D/E plate after UVLD, with significant reductions for all 5 surfaces (all P<.02). Surfaces in direct line of sight were significantly more likely to yield negative culture results after UVLD than before UVLD (all P<.001). Mean C. difficile spore log reductions ranged from 1.8 to 2.9. UVLD cycle times ranged from 34.2 to 100.1 minutes. For the 2-stage procedure, mean aerobic colony counts ranged from 10.0 to 89.2 CFUs per D/E plate before UVLD and were 0 CFUs per D/E plate after UVLD, with significant reductions for all 5 high-touch surfaces. UVLD cycle times ranged from 72.1 to 146.3 minutes. In-room ozone concentrations during UVLD ranged from undetectable to 0.012 ppm.

The mobile UV-C light unit significantly reduced aerobic colony counts and C. difficile spores on contaminated surfaces in patient rooms.

In April 2009, 2009 pandemic influenza A (H1N1) (hereafter, pH1N1) virus was identified in California, which caused widespread illness throughout the United States. We evaluated pH1N1 transmission among exposed healthcare personnel (HCP) and assessed the use and effectiveness of personal protective equipment (PPE) early in the outbreak.

Cohort study.

Two hospitals and 1 outpatient clinic in Southern California during March 28-April 24, 2009.

Sixty-three HCP exposed to 6 of the first 8 cases of laboratory-confirmed pH1N1 in the United States.

Baseline and follow-up questionnaires were used to collect demographic, epidemiologic, and clinical data. Paired serum samples were obtained to test for pH1N1-specific antibodies by microneutralization and hemagglutination-inhibition assays. Serology results were compared with HCP work setting, role, and self-reported PPE use.

Possible healthcare-associated pH1N1 transmission was identified in 9 (14%) of 63 exposed HCP; 6 (67%) of 9 seropositive HCP had asymptomatic infection. The highest attack rates occurred among outpatient HCP (6/19 [32%]) and among allied health staff (eg, technicians; 8/33 [24%]). Use of mask or N95 respirator was associated with remaining seronegative (P = .047). Adherence to PPE recommendations for preventing transmission of influenza virus and other respiratory pathogens was inadequate, particularly in outpatient settings.

pH1N1 transmission likely occurred in healthcare settings early in the pandemic associated with inadequate PPE use. Organizational support for a comprehensive approach to infectious hazards, including infection prevention training for inpatient- and outpatient-based HCP, is essential to improve HCP and patient safety.

To assess the impact and sustainability of a multifaceted intervention to prevent methicillin-resistant Staphylococcus aureus (MRSA) transmission implemented in 3 chronologically overlapping phases at 1 hospital.

Interrupted time-series analyses.

A Veterans Affairs hospital in the northeastern United States.

Individuals admitted to acute care units from October 1, 1999, through September 30, 2008. To calculate the monthly clinical incidence of MRSA colonization or infection, the number of MRSA-positive cultures obtained from a clinical site more than 48 hours after admission among patients with no MRSA-positive clinical cultures during the previous year was divided by patient-days at risk. Secondary outcomes included clinical incidence of methicillin-sensitive S. aureus colonization or infection and incidence of MRSA bloodstream infections.

The intervention—implemented in a surgical ward beginning October 2001, in a surgical intensive care unit beginning October 2003, and in all acute care units beginning July 2005—included systems and behavior change strategies to increase adherence to infection control precautions (eg, hand hygiene and active surveillance culturing for MRSA).

Hospital-wide, the clinical incidence of MRSA colonization or infection decreased after initiation of the intervention in 2001, compared with the period before intervention (P = .002), and decreased by 61% (P < .001) in the 7-year postintervention period. In the postintervention period, the hospital-wide incidence of MRSA bloodstream infection decreased by 50% (P = .02), and the proportion of S. aureus isolates that were methicillin resistant decreased by 30% (P < .001).

Sustained decreases in hospital-wide clinical incidence of MRSA colonization or infection, incidence of MRSA bloodstream infection, and proportion of S. aureus isolates resistant to methicillin followed implementation of a multifaceted prevention program at one Veterans Affairs hospital. Findings suggest that interventions designed to prevent transmission can impact endemic antimicrobial resistance problems.

New technologies have emerged in recent years for the disinfection of hospital rooms and equipment that may not be disinfected adequately using conventional methods. There are several hydrogen peroxide–based area decontamination technologies on the market, but no head-to-head studies have been performed.

We conducted a head-to-head in vitro comparison of a hydrogen peroxide vapor (HPV) system (Bioquell) and an aerosolized hydrogen peroxide (aHP) system (Sterinis).

The tests were conducted in a purpose-built 136-m3 test room.

One HPV generator and 2 aHP machines were used, following recommendations of the manufacturers. Three repeated tests were performed for each system. The microbiological efficacy of the 2 systems was tested using 6-log Tyvek-pouched Geobacillus stearo-thermophilus biological indicators (BIs). The indicators were placed at 20 locations in the first test and 14 locations in the subsequent 2 tests for each system.

All BIs were inactivated for the 3 HPV tests, compared with only 10% in the first aHP test and 79% in the other 2 aHP tests. The peak hydrogen peroxide concentration was 338 ppm for HPV and 160 ppm for aHP. The total cycle time (including aeration) was 3 and 3.5 hours for the 3 HPV tests and the 3 aHP tests, respectively. Monitoring around the perimeter of the enclosure with a handheld sensor during tests of both systems did not identify leakage.

One HPV generator was more effective than 2 aHP machines for the inactivation of G. stearothermophilus BIs, and cycle times were faster for the HPV system.

To evaluate the impact of a multifaceted intervention on compliance with evidence-based therapies and ventilator-associated pneumonia (VAP) rates.

Collaborative cohort before-after study.

Intensive care units (ICUs) predominantly in Michigan.

We implemented a multifaceted intervention to improve compliance with 5 evidence-based recommendations for mechanically ventilated patients and to prevent VAP. A standardized CDC definition of VAP was used and maintained at each site, and data on the number of VAPs and ventilator-days were obtained from the hospital's infection preventionists. Baseline data were reported and postimplementation data were reported for 30 months. VAP rates (in cases per 1,000 ventilator-days) were calculated as the proportion of ventilator-days per quarter in which patients received all 5 therapies in the ventilator care bundle. Two interventions to improve safety culture and communication were implemented first.

One hundred twelve ICUs reporting 3,228 ICU-months and 550,800 ventilator-days were included. The overall median VAP rate decreased from 5.5 cases (mean, 6.9 cases) per 1,000 ventilator-days at baseline to 0 cases (mean, 3.4 cases) at 16–18 months after implementation (P < .001) and 0 cases (mean, 2.4 cases) at 28-30 months after implementation (P < .001). Compared to baseline, VAP rates decreased during all observation periods, with incidence rate ratios of 0.51 (95% confidence interval, 0.41–0.64) at 16–18 months after implementation and 0.29 (95% confidence interval, 0.24–0.34) at 28–30 months after implementation. Compliance with evidence-based therapies increased from 32% at baseline to 75% at 16–18 months after implementation (P < .001) and 84% at 28–30 months after implementation (P < .001).

A multifaceted intervention was associated with an increased use of evidence-based therapies and a substantial (up to 71%) and sustained (up to 2.5 years) decrease in VAP rates.

To describe risk factors for and the outcome of infections in children receiving extracorporeal life support (ECLS) and to determine the need for removal of foreign bodies with bloodstream infections (BSIs) in children receiving ECLS.

Retrospective cohort study.

Tertiary care children's hospital.

Children receiving ECLS from May 1997 through May 2007.

For patients with documented infections, medical records were examined for demographic, clinical, and laboratory details. Patients with and without documented infections were compared with regard to demographic characteristics and ECLS course.

One hundred seventeen patients underwent ECLS for a total of 878 days (median, 5.12 days). Thirty-five patients (29.9%) developed 55 infections, including 21 BSIs (38.2%), 20 urinary tract infections (36.4%), 6 ventilator-associated pneumonia episodes (10.9%), 2 viral infections (3.6%), and 6 miscellaneous infections (10.9%). The rates (in cases per 1,000 ECLS-days) were 23.9 for BSI, 22.8 for urinary tract infection, and 6.8 for ventilator-associated pneumonia. There were no significant differences in the demographic characteristics, indications for ECLS, or ECLS course between infected and uninfected patients, except for the median duration of ECLS (10.1 vs 3.8 days; P < .001). One death was attributed to infection. Resolution of BSI occurred without removal of foreign bodies in 18 (85.7%) of 21 children.

Longer duration of ECLS was the only identified risk factor for infection. Mortality was not statistically significantly different between infected and uninfected patients. Most BSIs that occurred during ECLS cleared without removal of foreign bodies.

Considerable hospital resources are dedicated to minimizing the number of methicillin-resistant Staphylococcus aureus (MRSA) infections. One tool that is commonly used to achieve this goal is surveillance for MRSA colonization. This process is costly, and false-positive test results lead to isolation of individuals who do not carry MRSA. The performance of this technique would improve if patients who are at high risk of colonization could be readily targeted.

Five MRSA colonization prediction rules of varying complexity were derived in a population of 23,314 patients who were consecutively admitted to a US hospital and tested for colonization. Rules incorporated only prospectively collected, structured electronic data found in a patient's record within 1 day of hospital admission. These rules were tested in a validation cohort of 26,650 patients who were admitted to 2 other hospitals.

The prevalence of MRSA at hospital admission was 2.2% and 4.0% in the derivation and validation cohorts, respectively. Multivariable modeling identified predictors of MRSA colonization among demographic, admission-related, pharmacologic, laboratory, physiologic, and historical variables. Five prediction rules varied in their performance, but each could be used to identify the 30% of patients who accounted for greater than 60% of all cases of MRSA colonization and approximately 70% of all MRSA-associated patient-days. Most rules could also identify the 20% of patients with a greater than 8% chance of colonization and the 40% of patients among whom colonization prevalence was 2% or less.

We report electronic prediction rules that can fully automate triage of patients for MRSA-related hospital admission testing and that offer significant improvements on previously reported rules. The efficiencies introduced may result in savings to infection control programs with little sacrifice in effectiveness.

Sharps with engineered sharps injury protections (SESIPs) have been found to reduce risk of sharps injuries (Sis). We examined trends in SI rates among employees of acute care hospitals in Massachusetts, including the impact of SESIPs on SI trends during 2002-2007.

Prospective surveillance.

Seventy-six acute care hospitals licensed by the Massachusetts Department of Public Health.

Employees of acute care hospitals who reported Sis to their employers.

Data on Sis in acute care hospitals collected by the Massachusetts Sharps Injury Surveillance System were used to examine trends in SI rates over time by occupation, hospital size, and device. Negative binomial regression was used to assess trends.

During 2002-2007, 16,158 Sis among employees of 76 acute care hospitals were reported to the surveillance system. The annual SI rate decreased by 22%, with an annual decline of 4.7% (P < .001). Rates declined significantly among nurses (—7.2% per year; P < .001) but not among physicians (—0.9% per year; P = .553). SI rates associated with winged steel needles and hypodermic needles and syringes also declined significantly as the proportion of injuries involving devices with sharps injury prevention features increased during the same time period.

SI rates involving devices for which SESIPs are widely available and appear to be increasingly used have declined. The continued use of devices lacking SI protections for which SESIPs are available needs to be addressed. The extent to which injuries involving SESIPs are due to flaws in design or lack of experience and training must be examined.

The National Healthcare Safety Network (NHSN) has provided simple risk adjustment of surgical site infection (SSI) rates to participating hospitals to facilitate quality improvement activities; improved risk models were developed and evaluated.

Data reported to the NHSN for all operative procedures performed from January 1, 2006, through December 31, 2008, were analyzed. Only SSIs related to the primary incision site were included. A common set of patient- and hospital-specific variables were evaluated as potential SSI risk factors by univariate analysis. Some ific variables were available for inclusion. Stepwise logistic regression was used to develop the specific risk models by procedure category. Bootstrap resampling was used to validate the models, and the c-index was used to compare the predictive power of new procedure-specific risk models with that of the models with the NHSN risk index as the only variable (NHSN risk index model).

From January 1, 2006, through December 31, 2008, 847 hospitals in 43 states reported a total of 849,659 procedures and 16,147 primary incisional SSIs (risk, 1.90%) among 39 operative procedure categories. Overall, the median c-index of the new procedure-specific risk was greater (0.67 [range, 0.59–0.85]) than the median c-index of the NHSN risk index models (0.60 [range, 0.51–0.77]); for 33 of 39 procedures, the new procedure-specific models yielded a higher c-index than did the NHSN risk index models.

A set of new risk models developed using existing data elements collected through the NHSN improves predictive performance, compared with the traditional NHSN risk index stratification.

To devise a local strategy for eradication of a hospital-wide outbreak caused by carbapenem-resistant Klebsiella pneumoniae (CRKP).

Quasi-experimental, before-and-after, interrupted time-series study.

A 1,000-bed tertiary-care university teaching hospital.

Retrospectively, all relevant data were collected from the medical records of patients with CRKP infections from May 2006 through April 2007, the preintervention period. From May 1, 2007, through May 1, 2010, the postintervention period, the intervention was applied and prospectively followed. The 5 key elements of this strategy were an emergency department flagging system, the building of a cohort ward, the eradication of clusters, environmental and personnel hand cultures, and a carbapenem-restriction policy. The demographic and clinical parameters of patients colonized by and/or infected with CRKP were collected from medical records.

A total of 10,680 rectal cultures were performed for 8,376 patients; 433 (5.16%) and 370 (4.4%) were CRKP-colonized and CRKP-infected patients, respectively, and 789 (98%) of 803 patients were admitted to the CRKP cohort ward. The CRKP infection density was reduced from 5.26 to 0.18 per 10,000 patient-days (P<.001), and no nosocomial CRKP infections were diagnosed. Twenty-three percent of environmental cultures were found to be positive. Meropenem use was reduced from 283 ± 70.92 to 118 ± 74.32 defined daily doses per 1,000 patient-days (P<.001).

This intervention produced an enormous impact on patient location, surveillance cultures, and antibiotic policies and a massive investment in infection control resources.