To describe, during a 6-year period, multidrug-resistant bacterial carriage in an intensive care unit (ICU).

Prospective survey of 2,235 ICU patients with methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E).

A surgical ICU in a tertiary-care teaching hospital.

All admitted patients.

Nasal and rectal swabs were performed at admission and weekly thereafter. There was nasal application of mupirocin for MRSA carriers and selective digestive decontamination with local antibiotics for ESBL-E carriers.

The swab compliance rate was 82% at admission and 51% during ICU stay. The rates of MRSA carriage or infection were 4.2 new cases per 100 admissions and 7.9 cases per 1,000 patient-days during ICU stay. The rates of ESBL-E carriage or infection were 0.4 new case per 100 admissions and 3.9 cases per 1,000 patient-days during ICU stay. Importation of MRSA increased significantly over time from 3.2 new cases per 100 admissions during the first 3 years to 5.5 during the last 3 years. The rate of ICU-acquired ESBL-E decreased from 5.5 cases per 1,000 patient-days during the first 3 years to 1.9 cases during the last 3 years. Nasal and digestive decontamination had low efficacy in eradicating carriage.

MRSA remained poorly controlled throughout the hospital and was not just a problem in the ICU. MRSA thus requires more effective measures throughout the hospital. ESBL-E was mainly an ICU pathogen and our approach resulted in a clear decrease in the rate of acquisition in the ICU over time.

To study the extent to which selection bias poses problems for estimating the attributable cost of deep chest surgical-site infection (SSI) following coronary artery bypass graft (CABG) surgery.

Reanalysis of a prospective case–control study.

A large, Midwestern community medical center.

Cases were all patients who had an SSI (N = 41) following CABG and CABG and valve surgery between April 1996 and March 1998. Controls were every tenth uninfected patient (N = 160).

Estimates of the attributable cost of deep chest SSI were computed using unmatched comparison, matched comparison, linear regression, and Heckman's two-stage approach.

The attributable cost of deep chest SSI was estimated to be $20,012 by unmatched comparison, $19,579 by matched comparison, $20,103 by linear regression, and $14,211 by Heckman's two-stage method. Controlling for selection bias substantially reduced the cost estimate, but the coefficient capturing selection bias was not statistically significant.

Deep chest SSI significantly increases the cost of care for patients who undergo CABG surgery. Unmatched comparison, matched comparison, and linear regression estimated the attributable cost to be approximately $20,000. Although controlling for selection bias with Heckman's two-stage method resulted in a substantially smaller estimate, the coefficient for selection bias was not statistically significant, suggesting that the estimates derived from the other models should be acceptable. However, the magnitude of the difference between the models shows that the effect of selection bias can be substantial. Some exploration for selection bias is recommended when estimating the attributable cost of SSIs.

To determine the incidence and describe the changing epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection in Canadian hospitals from 1995–2007.

Forty-eight hospitals participating in the Canadian Nosocomial Infection Surveillance Program.

Prospective, laboratory-based surveillance for incident cases of MRSA colonization or infection among hospitalized patients.

Clinical and epidemiologic data were obtained by review of hospital records. Standard criteria were used to determine whether MRSA colonization or infection was present and whether the MRSA strain was healthcare associated or community associated. A representative subset of isolates was characterized by use of pulsed-field gel electrophoresis and staphylococcal cassette chromosome (SCC) mec typing.

From 1995 to 2007, a total of 37,169 hospitalized patients were newly identified as either infected or colonized with MRSA, and the overall incidence of both MRSA colonization and MRSA infection increased from 0.65 to 11.04 cases per 10,000 patient-days (P < .001). Of these 37,169 patients, 11,828 (32%) had an MRSA infection, and infection rate increased from 0.36 to 3.43 cases per 10,000 patient-days. The proportion of community-associated MRSA strains increased from 6% to 23% (P < .001). The most common genotype (47% of isolates) was CMRSA-2 (USA100/800); in 2007, CMRSA-10 (USA300) was the second most common strain (27% of isolates), associated with SCCmec type IV. Patients with CMRSA-10 were predominantly from western Canada and were more likely to be children (odds ratio [OR], 10.0 [95% confidence interval {CI}, 7.4–13.4]) and to have infection (OR, 2.3 [95% CI, 1.9–2.7]), especially skin and/or soft tissue infection (OR, 5.9 [95% CI, 5.0–6.9]).

The overall incidence of both MRSA colonization and MRSA infection increased 17-fold in Canadian hospitals from 1995 to 2007. There has also been a dramatic increase in cases of community-associated MRSA infection due to the CMRSA-10 (USA300) clone. Continued surveillance is needed to monitor the ongoing evolution of MRSA colonization or infection in Canada and globally.

To compare the number of surgical site infections (SSIs) registered after hospital discharge with respect to various surgical procedures and to identify the procedures for which postdischarge surveillance (PDS) is most important.

Prospective SSI surveillance with voluntary PDS. Recommended methods for PDS in the Dutch national nosocomial surveillance network are addition of a special registration card to the outpatient medical record, on which the surgeon notes clinical symptoms and whether a patient developed an SSI according to the definitions; an alternative method is examination of the outpatient medical record.

Hospitals participating in the Dutch national nosocomial surveillance network between 1996 and 2004.

We collected data on 131,798 surgical procedures performed in 64 of the 98 Dutch hospitals. PDS was performed according to one of the recommended methods for 31,134 operations (24%) and according to another active method for 32,589 operations (25%), and passive PDS was performed for 68,075 operations (52%). Relatively more SSIs were recorded after discharge for cases in which PDS was performed according to a recommended method (43%), compared with cases in which another active PDS method was used (30%) and cases in which passive PDS was used (25%). The highest rate of SSI after discharge was found for appendectomy (79% of operations), followed by knee prosthesis surgery (64%), mastectomy (61%), femoropopliteal or femorotibial bypass (53%), and abdominal hysterectomy (53%).

For certain surgical procedures, most SSIs develop after discharge. SSI rates will be underestimated if no PDS is performed. We believe we have found a feasible and sensitive method for PDS that, if patients routinely return to the hospital for a postdischarge follow-up visit, might be suitable for use internationally.

Over the past 2 decades, multiple interventions have been developed to prevent catheter-associated urinary tract infections (CAUTIs). The CAUTI prevention guidelines of the Healthcare Infection Control Practices Advisory Committee were recently revised.

To examine changes in rates of CAUTI events in adult intensive care units (ICUs) in the United States from 1990 through 2007.

Data were reported to the Centers for Disease Control and Prevention (CDC) through the National Nosocomial Infections Surveillance System from 1990 through 2004 and the National Healthcare Safety Network from 2006 through 2007. Infection preventionists in participating hospitals used standard methods to identify all CAUTI events (categorized as symptomatic urinary tract infection [SUTI] or asymptomatic bacteriuria [ASB]) and urinary catheter–days (UC-days) in months selected for surveillance. Data from all facilities were aggregated to calculate pooled mean annual SUTI and ASB rates (in events per 1,000 UC-days) by ICU type. Poisson regression was used to estimate percent changes in rates over time.

Overall, 36,282 SUTIs and 22,973 ASB episodes were reported from 367 facilities representing 1,223 adult ICUs, including combined medical/surgical (505), medical (212), surgical (224), coronary (173), and cardiothoracic (109) ICUs. All ICU types experienced significant declines of 19%–67% in SUTI rates and 29%–72% in ASB rates from 1990 through 2007. Between 2000 and 2007, significant reductions in SUTI rates occurred in all ICU types except cardiothoracic ICUs.

Since 1990, CAUTI rates have declined significantly in all major adult ICU types in facilities reporting to the CDC. Further efforts are needed to assess prevention strategies that might have led to these decreases and to implement new CAUTI prevention guidelines.

To describe the epidemiology of nosocomial outbreaks published in the scientific literature.

Descriptive information was obtained from a sample of 1,022 published nosocomial outbreaks from 1966 to 2002.

Published nosocomial outbreaks of the most important nosocomial pathogens were included in the database. A structured questionnaire was devised to extract information in a systematic manner on nosocomial outbreaks published in the literature. The following items were used: the reference, type of study (case reports or studies applying epidemiologic or fingerprinting methods), type of microorganism, setting, patients and personnel involved, type of infection, source of infection, mode of transmission, risk factors identified, and preventive measures applied.

Bloodstream infection was the most frequently identified type of infection (37.0%), followed by gastrointestinal infection (28.5%) and pneumonia (22.9%). In 37% of the outbreaks, the authors were not able to identify the sources. The most frequent sources were patients (25.7%), followed by medical equipment or devices (11.9%), the environment (11.6%), and the staff (10.9%). The mode of transmission remained unclear in 28.3% of the outbreaks. Transmission was by contact in 45.3%, by invasive technique in 16.1%, and through the air in 15.0%. The percentage of outbreaks investigated by case-control studies or cohort studies over the years was small (21% and 9%, respectively, for the whole time period).

Outbreak reports in the literature are a valuable resource and should be used for educational purposes as well as for preparing outbreak investigations.

To determine adherence to Hazard Analysis and Critical Control Points (HACCP) methods and to evaluate knowledge, attitudes, and practices of food-services staff with regard to food hygiene in hospitals.

A survey.

Hospital medical directors and food-services staff of 36 hospitals in Calabria, Italy.

A questionnaire about hospital characteristics, food-services organization, and measures and procedures for the control and prevention of foodborne diseases was sent to medical directors; a questionnaire about demographic and practice characteristics, knowledge, attitudes, and behaviors about control and prevention of foodborne diseases was sent to food-services staff. Multiple logistic regression analysis was performed.

Only 54% of the 27 responding hospitals were using the HACCP system and, of those using HACCP, 79% adopted a food-hygiene–practice manual; more than one half already had developed written procedures for food storage, personal hygiene, cleaning and disinfection; one half or less performed microbiological assessment of foods and surfaces. Of the 290 food-services staff who responded, 78.8% were aware of the five leading food-borne pathogens; this knowledge was significantly higher among those with a higher educational level and those who worked in hospitals that had implemented the HACCP system. Younger staff and those who had attended continuing educational courses about food hygiene and hospital foodborne diseases had a significantly higher knowledge of safe temperatures for food storage. A positive attitude toward foodborne-diseases prevention was reported by the great majority, and it was significantly higher in older respondents and in those working in hospitals with a lower number of beds. Only 54.9% of those involved in touching or serving unwrapped raw or cooked foods routinely used gloves during this activity; this practice was significantly greater among younger respondents and in those working in hospitals using HACCP.

Full implementation of the HACCP system and infection control policies in hospital food services is needed.

To characterize risk factors for surgical-site infection after spinal surgery.

A case–control study.

A 113-bed community hospital.

From January 1998 through June 2000, the incidence of surgical-site infection in patients undergoing laminectomy, spinal fusion surgery, or both increased at community hospital. A We compared 13 patients who acquired surgical-site infections after laminectomy, spinal fusion surgery, or both with 47 patients who were operated on during the same time period but did not acquire a surgical-site infection. Information collected included demographics, risk factors, personnel involved in the operations, length of hospital stay, and hospital costs.

Of 13 case-patients, 9 (69%) were obese, 9 (69%) had spinal compression, 5 (38.5%) had a history of tobacco use, and 4 (31%) had diabetes. Oxacillin-sensitive Staphylococcus aureus (6 of 13; 46%) was the most common organism isolated. Significant risk factors for postoperative spinal surgical-site infection were dural tear during the surgical procedure and the use of glue to cement the dural patch (3 of 13 [23%] vs 1 of 47 [2.1%] ; P = .02) and American Society of Anesthesiologists risk class of 3 or more (6 of 13 [46.2%] vs 7 of 47 [15%]; P = .02). Case-patients were more likely to have prolonged length of stay (median, 16 vs 4 days; P < .001). The average excess length of stay was 11 days and the excess cost per case was $12,477.

Dural tear and the use of glue should be evaluated as potential risk factors for spinal surgical-site infection. Systematic observation for potential lapses in sterile technique and surgical processes that may increase the risk of infection may help prevent spinal surgical-site infection.

To determine the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization among older residents of care homes in Leeds, United Kingdom, and to identify resident and care home risk factors for carriage.

We conducted a cross-sectional prevalence survey of 715 residents from 39 care homes. All participants were tested for nasal colonization with S. aureus, including MRSA. A short questionnaire was completed about each participant and each care home. A multivariable model was used to determine which risk factors were independently associated with MRSA colonization.

Care homes for older residents in Leeds, United Kingdom.

All residents in participating homes who were able to give informed consent.

A total of 159 of 715 residents tested positive for MRSA, for a prevalence of 22% (95% confidence interval, 18%—27%) The resultant multivariate model showed that residence in a home with a low ratio of nurses to beds, residence in a care home in a deprived area, male sex, presence of an invasive device, and a hospitalization duration of more than 10 days during the previous 2 years were independently associated with MRSA colonization.

This study found a large reservoir of MRSA within the care home population. Control strategies need to be coordinated between care homes and hospitals. Increasing the ratio of nurses to beds, reducing the duration of hospitalization, and improving the management of invasive devices could help reduce the prevalence of MRSA colonization. Further research is required to ascertain the potential health benefits of reducing the rate of MRSA colonization among care home residents.

To determine the attributable in-hospital mortality, length of stay (LOS), and cost of hospital-onset Clostridium difficile infection (HO-CDI).

Propensity score matching.

Six Pennsylvania hospitals (2 academic centers, 1 community teaching facility, and 3 community nonteaching facilities) contributing data to a clinical research database.

Adult inpatients between 2007 and 2008.

We defined HO-CDI in adult inpatients as a positive C. difficile toxin assay result from a specimen collected more than 48 hours after admission and more than 8 weeks following any previous positive result. We developed an HO-CDI propensity model and matched cases with noncases by propensity score at a 1 : 3 ratio. We further restricted matching within the same hospital, within the same principal disease group, and within a similar length of lead time from admission to onset of HO-CDI.

Among 77,257 discharges, 282 HO-CDI cases were identified. The propensity score-matched rate was 90%. Compared with matched noncases, HO-CDI patients had higher mortality (11.8% vs 7.3%; P<.05), longer LOS (median [interquartile range (IQR)], 12 [9–21] vs 11 [8–17] days; P< .01), and higher cost (median [IQR], $20,804 [$ll,059-$38,429] vs $16,634 [$9,413–$30,319]; P< .01). The attributable effect of HO-CDI was 4.5% (95% confidence interval [CI], 0.2%–8.7%; P<.05) for mortality, 2.3 days (95% CI, 0.9–3.8; P<.01) for LOS, and $6,117 (95% CI, $1,659–$10,574; P<.01) for cost.

Patients with HO-CDI incur additional attributable mortality, LOS, and cost burden compared with patients with similar primary clinical condition, exposure risk, lead time of hospitalization, and baseline characteristics.

Development of a numerical score to measure the microbial spectrum of antibiotic regimens (spectrum score) and method to identify antibiotic de-escalation events based on application of the score.

Web-based modified Delphi method.

Physician and pharmacist antimicrobial stewards practicing in the United States recruited through infectious diseases–focused listservs.

Three Delphi rounds investigated: organisms and antibiotics to include in the spectrum score, operationalization of rules for the score, and de-escalation measurement. A 4-point ordinal scale was used to score antibiotic susceptibility for organism-antibiotic domain pairs. Antibiotic regimen scores, which represented combined activity of antibiotics in a regimen across all organism domains, were used to compare antibiotic spectrum administered early (day 2) and later (day 4) in therapy. Changes in spectrum score were calculated and compared with Delphi participants’ judgments on de-escalation with 20 antibiotic regimen vignettes and with non-Delphi steward judgments on de-escalation of 300 pneumonia regimen vignettes. Method sensitivity and specificity to predict expert de-escalation status were calculated.

Twenty-four participants completed all Delphi rounds. Expert support for concepts utilized in metric development was identified. For vignettes presented in the Delphi, the sign of change in score correctly classified de-escalation in all vignettes except those involving substitution of oral antibiotics. The sensitivity and specificity of the method to identify de-escalation events as judged by non-Delphi stewards were 86.3% and 96.0%, respectively.

Identification of de-escalation events based on an algorithm that measures microbial spectrum of antibiotic regimens generally agreed with steward judgments of de-escalation status.

Infect Control Hosp Epidemiol 2014;35(9):1103-1113

To determine whether hand washing would increase with sustained feedback based on measurements of soap and paper towel consumption.

Prospective trial with a nonequivalent control group.

Open multibed rooms in the Omaha Veterans Affairs Medical Center's Surgical Intensive Care Unit (SICU) and Medical Intensive Care Unit (MICU).

Unit staff.

Every weekday from May 26 through December 8,1998, we recorded daytime soap and paper towel consumption, nurse staffing, and occupied beds in the SICU (intervention unit) and the MICU (control unit) and used these data to calculate estimated hand washing episodes (EHWEs), EHWEs per occupied bed per hour, and patient-to-nurse ratios. In addition, from May 26 through June 26 (baseline period) and from November 2 through December 8 (follow-up period), live observers stationed daily for random 4-hour intervals in the MICU and the SICU counted actual hand washing episodes (CHWEs). The intervention consisted of posting in the SICU, but not in the MICU, a graph showing the weekly EHWEs per occupied bed per hour for the preceding 5 weeks.

Directly counted hand washing fell in the SICU from a baseline of 2.68 ± 0.72 (mean ± standard deviation) episodes per occupied bed per hour to 1.92 ± 1.35 in the follow-up period. In the MICU, episodes fell from 2.58 ± 0.95 (baseline) to 1.74 ± 0.69. In the MICU, the withdrawal of live observers was associated with a decrease in estimated episodes from 1.36 ± 0.49 at baseline to 1.01 ± 0.36, with a return to 1.16 ± 0.50 when the observers returned. In the SICU, a similar decrease did not persist throughout a period of feedback. Estimated hand washing correlated negatively with the patient-to-nurse ratio (r = -0.35 for the MICU, r = -0.46 for the SICU).

Sustained feedback on hand washing failed to produce a sustained improvement. Live observers were associated with increased hand washing, even when they did not offer feedback. Hand washing decreased when the patient-to-nurse ratio increased.