The National Healthcare Safety Network surgical site infections risk models for hip (HPRO) and knee (KPRO) replacement are intended for case-mix adjustment when reporting surgical site infection rates across institutions, but they are not validated in external data sets

To evaluate the validity of HPRO and KPRO risk models and improvement in risk prediction with inclusion of information on morbid obesity and diabetes mellitus.

Retrospective cohort study.

A single-center cohort of 21,941 hip and knee replacement procedures performed between 2002 and 2009.

Discriminative ability was assessed using the concordance statistic (C statistic). Calibration was assessed using the Hosmer-Lemeshow goodness-of-fit tests.

The discrimination of HPRO was good, with a C statistic of 0.695 for surgical site infections and 0.749 for prosthetic joint infections. The discrimination of KPRO was worse than that of HPRO, with a C statistic of 0.592 for surgical site infections and 0.675 for prosthetic joint infections. Adding morbid obesity and diabetes mellitus to the HPRO and KPRO risk models modestly improved discrimination. There was no significant evidence of miscalibration based on the Hosmer-Lemeshow tests, but calibration of HPRO models appeared to be better than that of the KPRO models.

HPRO performed better than the KPRO in predicting surgical site infections after hip and knee replacements. Both fared well in predicting prosthetic joint infections.

Infect Control Hosp Epidemiol 2014;35(11):1323–1329

Our goal was to estimate the performance statistics of an electronic surveillance system for surgical site infections (SSIs), generally applicable in French hospitals

Three detection algorithms using 2 different data sources were tested retrospectively on 9 types of surgical procedures performed between January 2010 and December 2011 in the University Hospital of Nantes. The first algorithm was based on administrative codes, the second was based on bacteriological data, and the third used both data sources. For each algorithm, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) were calculated. The reference method was the hospital’s routine surveillance: a comprehensive review of the computerized medical charts of the patients who underwent one of the targeted procedures during the study period.

A 3,000-bed teaching hospital in western France.

We analyzed 4,400 targeted surgical procedures.

Sensitivity results varied significantly between the three algorithms, from 25% (95% confidence interval, 17–33) when using only administrative codes to 87% (80%–93%) with the bacteriological data and 90% (85%–96%) with the combined algorithm. Fewer variations were observed for specificity (91%–98%), PPV (21%–25%), and NPV (98% to nearly 100%). Overall, performance statistics were higher for deep SSIs than for superficial infections.

A reliable computer-enhanced SSI surveillance can easily be implemented in French hospitals using common data sources. This should allow infection control professionals to spend more time on prevention and education duties. However, a multicenter study should be conducted to assess the generalizability of this method.

Infect Control Hosp Epidemiol 2014;35(11):1330–1335

Healthcare worker hand hygiene is known to prevent healthcare-associated infections, but there are few data on patient hand hygiene despite the fact that nosocomial pathogens may be acquired by patients via their own unclean hands. The purpose of this study was to measure patient hand hygiene behavior in the hospital after visiting a bathroom, before eating, and on entering and leaving their rooms

Cross-sectional study.

Acute care teaching hospital in Canada.

Convenience sample of 279 adult patients admitted to 3 multiorgan transplant units between July 2012 and March 2013.

Patient use of alcohol-based hand rub and soap dispensers was measured using an ultrasound-based real-time location system during visits to bathrooms, mealtimes, kitchen visits, and on entering and leaving their rooms.

Overall, patients performed hand hygiene during 29.7% of bathroom visits, 39.1% of mealtimes, 3.3% of kitchen visits, 2.9% of room entries, and 6.7% of room exits.

Patients appear to perform hand hygiene infrequently, which may contribute to transmission of pathogens from the hospital environment via indirect contact or fecal-oral routes.

Infect Control Hosp Epidemiol 2014;35(11):1336–1341

To evaluate whether dental treatment may enhance oral antisepsis, thus preventing more effectively lower respiratory tract infections (LRTIs) among critically ill patients

Observer-blind randomized clinical trial.

General intensive care unit (ICU) for adult patients.

We analyzed data from 254 adult patients who stayed for at least 48 hours in the ICU.

Patients were randomized by means of rolling dice. The experimental group (n = 127) had access to dental care provided by a dental surgeon, 4–5 times a week. Besides routine oral hygiene, care also included teeth brushing, tongue scraping, removal of calculus, atraumatic restorative treatment of caries, and tooth extraction. The control group (n = 127) had access to routine oral hygiene only, which included the use of chlorhexidine as a mouth rinse, which was performed by the ICU nurse staff.

The primary study outcome was the LRTI incidence, which was 8.7% in the experimental group and 18.1% in the control group (adjusted relative risk [RR], 0.44 [95% confidence interval (CI), 0.20–0.96]; P = .04). Ventilator-associated pneumonia rates per 1,000 ventilator-days were 16.5 (95% CI, 9.8–29.5) in the control group and 7.6 (95% CI, 3.3–15.0) in the experimental group (P < .05). Mortality rates were similar between both study groups: 31.5% in the control group versus 29.1% in the experimental group (adjusted RR, 0.93 [95% CI, 0.52–1.65]; P = .796). No severe adverse events related to oral care were observed during the study.

Dental treatment was safe and effective in the prevention of LRTI among critically ill patients who were expected to stay at least 48 hours in the ICU.

Brazilian Clinical Trials Registry, affiliated with the World Health Organization’s International Clinical Trial Registry Platform: U1111-1152-2671.

Infect Control Hosp Epidemiol 2014;35(11):1342–1348

Despite an increasing understanding of the importance of near-patient surfaces in the transmission of healthcare-associated pathogens, there remains a need to define the relative clinical effectiveness of disinfection interventions

A serial 2-phase evaluation of the clinical effectiveness of 2 surface disinfectants.

A general acute care hospital.

A unique system for quantifying bioburden reduction while monitoring the possible impact of differences in cleaning thoroughness was used to compare the clinical effectiveness of a traditional quaternary ammonium compound (QAC) and a novel peracetic acid/hydrogen peroxide disinfectant (ND) as part of terminal room cleaning.

As a result of QAC cleaning, 93 (40%) of 237 cleaned surfaces confirmed by fluorescent marker (DAZO) removal were found to have complete removal of aerobic bioburden. During the ND phase of the study, bioburden was removed from 211 (77%) of 274 cleaned surfaces. Because there was no difference in the thoroughness of cleaning with either disinfectant (65.3% and 66.4%), the significant (P > .0001) difference in bioburden reduction can be attributed to better cleaning efficacy with the ND.

In the context of the study design, the ND was 1.93 times more effective in removing bacterial burden than the QAC (P > .0001). Furthermore, the study design represents a new research paradigm in which 2 interventions can be compared by concomitantly and objectively analyzing both the product and process variables in a manner that can be used to define the relative effectiveness of all disinfection cleaning interventions.

Infect Control Hosp Epidemiol 2014;35(11):1349–1355

To evaluate the efficacy of a new monochloramine generation system for control of Legionella in a hospital hot water distribution system

A 495-bed tertiary care hospital in Pittsburgh, Pennsylvania. The hospital has 12 floors covering approximately 78,000 m2.

The hospital hot water system was monitored for a total of 29 months, including a 5-month baseline sampling period prior to installation of the monochloramine system and 24 months of surveillance after system installation (postdisinfection period). Water samples were collected for microbiological analysis (Legionella species, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species, nitrifying bacteria, heterotrophic plate count [HPC] bacteria, and nontuberculous mycobacteria). Chemical parameters monitored during the investigation included monochloramine, chlorine (free and total), nitrate, nitrite, total ammonia, copper, silver, lead, and pH.

A significant reduction in Legionella distal site positivity was observed between the pre- and postdisinfection periods, with positivity decreasing from an average of 53% (baseline) to an average of 9% after monochloramine application (P > .05). Although geometric mean HPC concentrations decreased by approximately 2 log colony-forming units per milliliter during monochloramine treatment, we did not observe significant changes in other microbial populations.

This is the first evaluation in the United States of a commercially available monochloramine system installed on a hospital hot water system for Legionella disinfection, and it demonstrated a significant reduction in Legionella colonization. Significant increases in microbial populations or other negative effects previously associated with monochloramine use in large municipal cold water systems were not observed.

Infect Control Hosp Epidemiol 2014;35(11):1356–1363

To establish the source and contamination routes resulting in positive clinical and surveillance microbiological cultures with carbapenem-resistant, GIM-1 metallo-β-lactamase–positive Acinetobacter pitii and Acinetobacter radioresistens from 21 patients in 8 departments

Retrospective, descriptive study.

A 1,300-bed tertiary care academic medical facility consisting of 90 buildings linked by a pneumatic transport system (PTS).

Microbiological workup of the cluster strains included matrix-assisted laser desorption/ionization time-of-flight species identification, phenotypic carbapenemase tests, polymerase chain reaction–based genotyping of carbapenemase, and pulsed-field gel electrophoresis. Outbreak management procedures were employed according to institutional regulations.

The rarity of GIM-1 Acinetobacter species in the hospital and region, the lack of epidemiological links between patients, and the fact that in some patients the apparent colonization was clearly nonnosocomial prompted the suspicion of a pseudo-outbreak. Numerous environmental cultures were positive for GIM-1-positive Acinetobacter (including archived sample requisition forms, PTS capsules, cultures from line-diverter and dispenser stations, and sterilized transport capsules following PTS delivery). Moreover, it was observed that condensation fluid from subterranean PTS tubing resulted in water entry in PTS capsules, possibly conferring specimen contamination. After extensive system disinfection, environmental surveys of the PTS were negative, and no further positive patient specimens were encountered.

This is the first report of a PTS-associated pseudo-outbreak. The large number of falsely positive patient-related specimens in conjunction with the potential hazard of airborne and contact spread of multidrug-resistant microorganisms (in this case, GIM-1 carbapenem-resistant Acinetobacter species) underscores the need for implementation of infection control–based monitoring and operating procedures in a hospital PTS.

To understand the genotypic spectrum of environmental contamination of Staphylococcus aureus in households and its persistence

Prospective longitudinal cohort investigation.

Index participants identified at 2 academic medical centers.

Adults and children with S. aureus skin infections and their household contacts in Los Angeles and Chicago.

Household fomites were surveyed for contamination at baseline and 3 months. All isolates underwent genetic typing.

We enrolled 346 households, 88% of which completed the 3-month follow-up visit. S. aureus environmental contamination was 49% at baseline and 51% at 3 months. Among households with a USA300 methicillin-resistant S. aureus (MRSA) body infection isolate, environmental contamination with an indistinguishable MRSA strain was 58% at baseline and 63% at 3 months. Baseline factors associated with environmental contamination by the index subject’s infection isolate were body colonization by any household member with the index subject’s infection isolate at baseline (odds ratio [OR], 10.93 [95% confidence interval (CI), 5.75–20.79]), higher housing density (OR, 1.47 [95% CI, 1.10–1.96]), and more frequent household fomite cleaning (OR, 1.62 [95% CI, 1.16–2.27]). Household environmental contamination with the index subject’s infection strain at 3 months was associated with USA300 MRSA and a synergistic interaction between baseline environmental contamination and body colonization by any household member with the index subject’s infection strain.

We found that infecting S. aureus isolates frequently persisted environmentally in households 3 months after skin infection. Presence of pathogenic S. aureus strain type in the environment in a household may represent a persistent reservoir that places household members at risk of future infection.

Infect Control Hosp Epidemiol 2014;35(11):1373–1382

Exposure of healthcare personnel to bloodborne pathogens (BBPs) can be prevented in part by using safety-engineered sharp devices (SESDs) and other safe practices, such as double gloving. In some instances, however, safer devices and practices cannot be utilized because of procedural factors or the lack of a manufactured safety device for the specific clinical use. In these situations, a standardized system to examine requests for waiver from expected practices is necessary

Before-after program analysis.

Large academic medical center.

Vanderbilt University Medical Center developed a formalized system for an improved waiver process, including an online submission and tracking site, and standards surrounding implementation of core safe practices. The program’s impact on sharp device injuries and utilization of double gloving and blunt sutures was examined.

Following implementation of the enhanced program, there was an increase in the amount of undergloves and blunt sutures purchased for surgical procedures, suggesting larger utilization of these practices. The rate of sharp device injuries of all at-risk employees decreased from 2.32% to 2.12%, but this decline was not statistically significant (P = .14). The proportion of reported injuries that were deemed preventable significantly decreased from 72.7% (386/531) before implementation to 63.9% (334/523; P = .002) after implementation of the enhanced program.

An enhanced BBP protection program was successful at providing guidance to increase safe practices and at improving the management of SESD waiver requests and was associated with a reduction in preventable sharp device injuries.

To develop a candidate definition for central line–associated bloodstream infection (CLABSI) in neonates with presumed mucosal barrier injury due to gastrointestinal (MBI-GI) conditions and to evaluate epidemiology and microbiology of MBI-GI CLABSI in infants

Multicenter retrospective cohort study.

Neonatal intensive care units from 14 US children’s hospitals and pediatric facilities.

A multidisciplinary focus group developed a candidate MBI-GI CLABSI definition based on presence of an MBI-GI condition, parenteral nutrition (PN) exposure, and an eligible enteric organism. CLABSI surveillance data from participating hospitals were supplemented by chart review to identify MBI-GI conditions and PN exposure.

During 2009–2012, 410 CLABSIs occurred in 376 infants. MBI-GI conditions and PN exposure occurred in 149 (40%) and 324 (86%) of these 376 neonates, respectively. The distribution of pathogens was similar among neonates with versus without MBI-GI conditions and PN exposure. Fifty-nine (16%) of the 376 initial CLABSI episodes met the candidate MBI-GI CLABSI definition. Subsequent versus initial CLABSIs were more likely to be caused by an enteric organism (22 of 34 [65%] vs 151 of 376 [40%]; P = .009) and to meet the candidate MBI-GI CLABSI definition (19 of 34 [56%] vs 59 of 376 [16%]; P < .01).

While MBI-GI conditions and PN exposure were common, only 16% of initial CLABSIs met the candidate definition of MBI-GI CLABSI. The high proportion of MBI-GI CLABSIs among subsequent infections suggests that infants with MBI-GI CLABSI should be a population targeted for further surveillance and interventional research.

Infect Control Hosp Epidemiol 2014;35(11):1391–1399

To determine the attributable inpatient costs of recurrent Clostridium difficile infections (CDIs)

Retrospective cohort study.

Academic, urban, tertiary care hospital.

A total of 3,958 patients aged 18 years or more who developed an initial CDI episode from 2003 through 2009.

Data were collected electronically from hospital administrative databases and were supplemented with chart review. Patients with an index CDI episode during the study period were followed up for 180 days from the end of their index hospitalization or the end of their index CDI antibiotic treatment (whichever occurred later). Total hospital costs during the outcome period for patients with recurrent versus a single episode of CDI were analyzed using zero-inflated lognormal models.

There were 421 persons with recurrent CDI (recurrence rate, 10.6%). Recurrent CDI case patients were significantly more likely than persons without recurrence to have any hospital costs during the outcome period (P < .001). The estimated attributable cost of recurrent CDI was $11,631 (95% confidence interval, $8,937–$14,588).

The attributable costs of recurrent CDI are considerable. Patients with recurrent CDI are significantly more likely to have inpatient hospital costs than patients who do not develop recurrences. Better strategies to predict and prevent CDI recurrences are needed.

Infect Control Hosp Epidemiol 2014;35(11):1400–1407