We sought to determine whether the bacterial burden in the nares, as determined by the cycle threshold (CT) value from real-time MRSA PCR, is predictive of environmental contamination with MRSA.

Patients identified as MRSA nasal carriers per hospital protocol were enrolled within 72 hours of room admission. Patients were excluded if (1) nasal mupirocin or chlorhexidine body wash was used within the past month or (2) an active MRSA infection was suspected. Four environmental sites, 6 body sites and a wound, if present, were cultured with premoistened swabs. All nasal swabs were submitted for both a quantitative culture and real-time PCR (Roche Lightcycler, Indianapolis, IN).

At study enrollment, 82 patients had a positive MRSA-PCR. A negative correlation of moderate strength was observed between the CT value and the number of MRSA colonies in the nares (r=−0.61; P<0.01). Current antibiotic use was associated with lower levels of MRSA nasal colonization (CT value, 30.2 vs 27.7; P<0.01). Patients with concomitant environmental contamination had a higher median log MRSA nares count (3.9 vs 2.5, P=0.01) and lower CT values (28.0 vs 30.2; P<0.01). However, a ROC curve was unable to identify a threshold MRSA nares count that reliably excluded environmental contamination.

Patients with a higher burden of MRSA in their nares, based on the CT value, were more likely to contaminate their environment with MRSA. However, contamination of the environment cannot be predicted solely by the degree of MRSA nasal colonization.

No previous studies of methicillin-resistant Staphylococcus aureus (MRSA) epidemiology in adult intensive care units (ICUs) have assessed the utility of rapid, highly discriminatory strain typing in the investigation of transmission events.

Observational.

A 22-bed medical-surgical adult ICU.

Those admissions MRSA-positive on initial screening and all admissions <48 hours in duration were excluded, leaving a cohort of 653 patients (median age, 61 years; APACHE-II, 19).

We conducted this study of MRSA transmission over 1 year (August 1, 2011 to July 31, 2012) using a multiplex PCR-based reverse line blot (mPCR/RLB) assay to genotype isolates from surveillance swabs obtained at admission and twice weekly during ICU stays. MRSA prevalence and incidence rates were calculated and transmission events were identified using strain matching. Colonization pressure was calculated daily by summation of all MRSA cases.

Of 1,030 admissions to ICU during the study period, 349 patients were excluded. MRSA acquisition occurred during 31 of 681 (4.6%) remaining admissions; 19 of 31(61%) acquisitions were genotype-confirmed, including 7 (37%) due to the most commonly transmitted strain. Moving averages of MRSA patient numbers on the days prior to a documented event were used in a Poisson regression model. A significant association was found between transmission and colonization pressure when the average absolute colonization pressure on the previous day was ≥3 (χ2=7.41, P=0.01).

mPCR/RLB characterizes MRSA isolates within a clinically useful time frame for identification of single-source clusters within the ICU. High MRSA colonization pressure (≥3 MRSA-positive patients) on a given day is associated with an increased likelihood of a transmission event.

Infect Control Hosp Epidemiol 2014;00(0):1–9

To identify important risk factors for recurrent methicillin-resistant Staphylococcus aureus (MRSA) to assist clinicians in identifying high-risk patients for continued surveillance and follow-up.

In this retrospective cohort study, we examined patients with MRSA bacteremia at 122 Veterans Affairs medical facilities from January 1, 2003, through December 31, 2010. Recurrent MRSA bacteremia was identified by a positive blood culture result from 2 to 180 days after index hospitalization discharge. Subset analyses were performed to evaluate risk factors for early-onset (2–60 days after discharge) and late-onset (61–180 days after discharge) recurrence. Risk factors were evaluated using Cox proportional hazards regression.

Of 18,425 patients, 1,159 (6.3%) had recurrent MRSA bacteremia. The median time to recurrence was 63 days. Longer duration of index bacteremia, increased severity of illness, receipt of only vancomycin, community-acquired infection, and several comorbidities were risk factors for recurrence. Congestive heart failure, hypertension, and rheumatoid arthritis/collagen disease were risk factors for early-onset but not late-onset recurrence. Geographic region and cardiac arrhythmias were risk factors for late-onset but not early-onset recurrence.

Risk factors for recurrent MRSA bacteremia included comorbidities, severity of illness, duration of bacteremia, and receipt of only vancomycin. Awareness of risk factors may be important at patient discharge for implementation of quality improvement initiatives including surveillance, follow-up, and education for high-risk patients.

Infect Control Hosp Epidemiol 2015;00(0): 1–7

The incidence of Clostridium difficile infection (CDI) has increased among hospitalized patients and is a common complication of leukemia. We investigated the risks for and outcomes of CDI in hospitalized leukemia patients.

Adults with a primary diagnosis of leukemia were extracted from the United States Nationwide Inpatient Sample database, 2005–2011. The primary outcomes of interest were CDI incidence, CDI-associated mortality, length of stay (LOS), and charges. In a secondary analysis, we sought to identify independent risk factors for CDI in leukemia patients. Logistic regression was used to derive odds ratios (ORs) adjusted for potential confounders.

A total of 1,243,107 leukemia hospitalizations were identified. Overall CDI incidence was 3.4% and increased from 3.0% to 3.5% during the 7-year study period. Leukemia patients had 2.6-fold higher risk for CDI than non-leukemia patients, adjusted for LOS. CDI was associated with a 20% increase in mortality of leukemia patients, as well as 2.6 times prolonged LOS and higher hospital charges. Multivariate analysis revealed that age >65 years (OR, 1.13), male gender (OR, 1.14), prolonged LOS, admission to teaching hospital (OR, 1.16), complications of sepsis (OR, 1.83), neutropenia (OR, 1.35), renal failure (OR, 1.18), and bone marrow or stem cell transplantation (OR, 1.27) were significantly associated with CDI occurrence.

Hospitalized leukemia patients have greater than twice the risk of CDI than non-leukemia patients. The incidence of CDI in this population increased 16.7% from 2005 to 2011. Development of CDI in leukemia patients was associated with increased mortality, longer LOS, and higher hospital charges.

Infect Control Hosp Epidemiol 2015;36(7):794–801

Policymakers may wish to align healthcare payment and quality of care while minimizing unintended consequences, particularly for safety net hospitals.

To determine whether the 2008 Centers for Medicare and Medicaid Services Hospital-Acquired Conditions policy had a differential impact on targeted healthcare-associated infection rates in safety net compared with non–safety net hospitals.

Interrupted time-series design.

Nonfederal acute care hospitals that reported central line–associated bloodstream infection and ventilator-associated pneumonia rates to the Centers for Disease Control and Prevention’s National Health Safety Network from July 1, 2007, through December 31, 2013.

We did not observe changes in the slope of targeted infection rates in the postpolicy period compared with the prepolicy period for either safety net (postpolicy vs prepolicy ratio, 0.96 [95% CI, 0.84–1.09]) or non–safety net (0.99 [0.90–1.10]) hospitals. Controlling for prepolicy secular trends, we did not detect differences in an immediate change at the time of the policy between safety net and non–safety net hospitals (P for 2-way interaction, .87).

The Centers for Medicare and Medicaid Services Hospital-Acquired Conditions policy did not have an impact, either positive or negative, on already declining rates of central line–associated bloodstream infection in safety net or non–safety net hospitals. Continued evaluations of the broad impact of payment policies on safety net hospitals will remain important as the use of financial incentives and penalties continues to expand in the United States.

Infect Control Hosp Epidemiol 2015;00(0): 1–7

To evaluate time trends in surgical site infection (SSI) rates and SSI pathogens in Australia.

Prospective multicenter observational cohort study.

A group of 81 Australian healthcare facilities participating in the Victorian Healthcare Associated Infection Surveillance System (VICNISS).

All patients underwent surgeries performed between October 1, 2002, and June 30, 2013. National Healthcare Safety Network SSI surveillance methods were employed by the infection prevention staff at the participating hospitals.

Procedure-specific risk-adjusted SSI rates were calculated. Pathogen-specific and antimicrobial-resistant (AMR) infections were modeled using multilevel mixed-effects Poisson regression.

A total of 183,625 procedures were monitored, and 5,123 SSIs were reported. Each year of observation was associated with 11% risk reduction for superficial SSI (risk ratio [RR], 0.89; 95% confidence interval [CI], 0.88–0.90), 9% risk reduction for deep SSI (RR, 0.91; 95% CI, 0.90–0.93), and 5% risk reduction for organ/space SSI (RR, 0.95; 95% CI, 0.93–0.97). Overall, 3,318 microbiologically confirmed SSIs were reported. Of these SSIs, 1,174 (35.4%) were associated with orthopedic surgery, 827 (24.9%) with coronary artery bypass surgery, 490 (14.8%) with Caesarean sections, and 414 (12.5%) with colorectal procedures. Staphylococcus aureus was the most frequently identified pathogen, and a statistically significant increase in infections due to ceftriaxone-resistant Escherichia coli was observed (RR, 1.37; 95% CI, 1.10–1.70).

Standardized SSI surveillance methods have been implemented in Victoria, Australia. Over an 11-year period, diminishing rates of SSIs have been observed, although AMR infections increased significantly. Our findings facilitate the refinement of recommended surgical antibiotic prophylaxis regimens and highlight the need for a more expansive national surveillance strategy to identify changes in epidemiology.

Infect Control Hosp Epidemiol 2015;00(0): 1–8

To determine the effect of interhospital patient sharing via transfers on the rate of Clostridium difficile infections in a hospital.

Retrospective cohort.

Using data from the Healthcare Cost and Utilization Project California State Inpatient Database, 2005–2011, we identified 2,752,639 transfers. We then constructed a series of networks detailing the connections formed by hospitals. We computed 2 measures of connectivity, indegree and weighted indegree, measuring the number of hospitals from which transfers into a hospital arrive, and the total number of incoming transfers, respectively. Next, we estimated a multivariate model of C. difficile infection cases using the log-transformed network measures as well as covariates for hospital fixed effects, log median length of stay, log fraction of patients aged 65 or older, and quarter and year indicators as predictors.

We found an increase of 1 in the log indegree was associated with a 4.8% increase in incidence of C. difficile infection (95% CI, 2.3%–7.4%) and an increase of 1 in log weighted indegree was associated with a 3.3% increase in C. difficile infection incidence (1.5%–5.2%). Moreover, including measures of connectivity in our models greatly improved their fit.

Our results suggest infection control is not under the exclusive control of a given hospital but is also influenced by the connections and number of connections that hospitals have with other hospitals.

Infect. Control Hosp. Epidemiol. 2015;36(9):1031–1037

To determine the relative risk of invasive methicillin-resistant Staphylococcus aureus (MRSA) infection among non-colonized (NC) patients, intermittently colonized (IC) patients, and persistently colonized (PC) patients.

Observational cohort study of patient data collected longitudinally over a 41-month period.

Department of Veterans Affairs Eastern Colorado Healthcare System, a tertiary care medical center.

Any patient who received ≥5 MRSA nasal swab tests between February 20, 2010, and July 26, 2013. In total, 3,872 patients met these criteria, 0 were excluded, 95% were male, 71% were white, and the mean age was 62.9 years on the date of study entry.

Patients were divided into cohorts based on MRSA colonization status. Physicians reviewed medical records to identify invasive infection and were blinded to colonization status. Cox and Kaplan-Meier analyses were used to assess the relationship between colonization status and invasive infection.

In total, 102 patients developed invasive MRSA infections, 16.3% of these were PC patients, 11.2% of these were IC patients, and 0.5% of these were NC patients. PC patients were at higher risk of invasive infection than NC patients (hazard ratio [HR] 36.8; 95% CI, 18.4–73.6; P<.001). IC patients were also at higher risk than NC patients (HR, 22.8; 95% CI, 13.3–39.3; P<.001). The difference in risk between PC and IC patients was not statistically significant (HR, 1.61; 95% CI, 0.94–2.78, P=.084). Alternate analysis methods confirmed these results.

The risk of invasive MRSA infection is much higher among PC and IC patients, supporting routine clinical testing for colonization. However, this risk is similar among PC and IC patients, suggesting that distinguishing between the 2 colonization states may not be clinically important.

Infect. Control Hosp. Epidemiol. 2015;36(11):1292–1297

While incidence, mortality, morbidity, and recurrence rates of C. difficile infection (CDI) among the critically ill have been investigated, the impact of its recurrence on 30-day rehospitalization (ReAd), an important policy focus, has not been examined.

Secondary analysis of a multicenter retrospective cohort study

Adult critically ill patients who survived their index hospitalization complicated by CDI

CDI was defined by diarrhea or pseudomembranous colitis and a positive assay for C. difficile toxins A and/or B. CDI recurrence (rCDI) was defined as diarrhea, positive C. difficile toxin and need for retreatment after cessation of therapy. Descriptive statistics and a logistic regression examined ReAd rates and characteristics, and factors that impact it.

Among 287 hospital survivors, 76 (26.5%) required ReAd (ReAd+). At baseline, the ReAd+ group did not differ significantly from the ReAd– group based on demographics, comorbidities, APACHE II scores, or ICU type. ReAd+ patients were more likely to have hypotension at CDI onset (48.7% vs 34.1%, P=.025) and to require vasopressors (40.0% vs 27.1%, P=.038); they were less likely to require mechanical ventilation (56.0% vs 77.3%, P<.001). A far greater proportion of ReAd+ than ReAd– had developed a recurrence either during the index hospitalization or within 30 days after discharge (32.89% vs 2.84%, P<.001). In a logistic regression, rCDI was a strong predictor of ReAd+ (adjusted odd ratio, 15.33, 95% confidence interval, 5.68–41.40).

Greater than 25% of all survivors of critical illness complicated by CDI require readmission within 30 days of discharge. CDI recurrence is a strong predictor of such rehospitalizations.

Infect Control Hosp Epidemiol 2014;00(0): 1–7

Whether contact precautions (CP) are required to control the endemic transmission of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) in acute care hospitals is controversial in light of improvements in hand hygiene, MRSA decolonization, environmental cleaning and disinfection, fomite elimination, and chlorhexidine bathing.

To provide a framework for decision making around use of CP for endemic MRSA and VRE based on a summary of evidence related to use of CP, including impact on patients and patient care processes, and current practices in use of CP for MRSA and VRE in US hospitals.

A literature review, a survey of Society for Healthcare Epidemiology of America Research Network members on use of CP, and a detailed examination of the experience of a convenience sample of hospitals not using CP for MRSA or VRE.

Hospital epidemiologists and infection prevention experts.

No high quality data support or reject use of CP for endemic MRSA or VRE. Our survey found more than 90% of responding hospitals currently use CP for MRSA and VRE, but approximately 60% are interested in using CP in a different manner. More than 30 US hospitals do not use CP for control of endemic MRSA or VRE.

Higher quality research on the benefits and harms of CP in the control of endemic MRSA and VRE is needed. Until more definitive data are available, the use of CP for endemic MRSA or VRE in acute care hospitals should be guided by local needs and resources.

Infect Control Hosp Epidemiol 2015;36(10):1163–1172

Limitations in sample size, overly inclusive antibiotic classes, lack of adjustment of key risk variables, and inadequate assessment of cases contribute to widely ranging estimates of risk factors for Clostridium difficile infection (CDI).

To incorporate all key CDI risk factors in addition to 27 antibiotic classes into a single comprehensive model.

Retrospective cohort study.

Kaiser Permanente Southern California.

Members of Kaiser Permanente Southern California at least 18 years old admitted to any of its 14 hospitals from January 1, 2011, through December 31, 2012.

Hospital-acquired CDI cases were identified by polymerase chain reaction assay. Exposure to major outpatient antibiotics (10 classes) and those administered during inpatient stays (27 classes) was assessed. Age, sex, self-identified race/ethnicity, Charlson Comorbidity Score, previous hospitalization, transfer from a skilled nursing facility, number of different antibiotic classes, statin use, and proton pump inhibitor use were also assessed. Poisson regression estimated adjusted risk of CDI.

A total of 401,234 patients with 2,638 cases of incident CDI (0.7%) were detected. The final model demonstrated highest CDI risk associated with increasing age, exposure to multiple antibiotic classes, and skilled nursing facility transfer. Factors conferring the most reduced CDI risk were inpatient exposure to tetracyclines and first-generation cephalosporins, and outpatient macrolides.

Although type and aggregate antibiotic exposure are important, the factors that increase the likelihood of environmental spore acquisition should not be underestimated. Operationally, our findings have implications for antibiotic stewardship efforts and can inform empirical and culture-driven treatment approaches.

Infect. Control Hosp. Epidemiol. 2015;36(12):1409–1416

The National Healthcare Safety Network classifies breast operations as clean procedures with an expected 1%–2% surgical site infection (SSI) incidence. We assessed differences in SSI incidence following mastectomy with and without immediate reconstruction in a large, geographically diverse population.

Retrospective cohort study

Commercially insured women aged 18–64 years with ICD-9-CM procedure or CPT-4 codes for mastectomy from January 1, 2004 through December 31, 2011

Incident SSIs within 180 days after surgery were identified by ICD-9-CM diagnosis codes. The incidences of SSI after mastectomy with and without immediate reconstruction were compared using the χ2 test.

From 2004 to 2011, 18,696 mastectomy procedures among 18,085 women were identified, with immediate reconstruction in 10,836 procedures (58%). The incidence of SSI within 180 days following mastectomy with or without reconstruction was 8.1% (1,520 of 18,696). In total, 49% of SSIs were identified within 30 days post-mastectomy, 24.5% were identified 31–60 days post-mastectomy, 10.5% were identified 61–90 days post-mastectomy, and 15.7% were identified 91–180 days post-mastectomy. The incidences of SSI were 5.0% (395 of 7,860) after mastectomy only, 10.3% (848 of 8,217) after mastectomy plus implant, 10.7% (207 of 1,942) after mastectomy plus flap, and 10.3% (70 of 677) after mastectomy plus flap and implant (P<.001). The SSI risk was higher after bilateral compared with unilateral mastectomy with immediate reconstruction (11.4% vs 9.4%, P=.001) than without (6.1% vs 4.7%, P=.021) immediate reconstruction.

SSI incidence was twice that after mastectomy with immediate reconstruction than after mastectomy alone. Only 49% of SSIs were coded within 30 days after operation. Our results suggest that stratification by procedure type facilitates comparison of SSI rates after breast operations between facilities.

Infect Control Hosp Epidemiol 2015;36(8):907–914

To observe patient care across hemodialysis facilities enrolled in the National Opportunity to Improve Infection Control in ESRD (end-stage renal disease) (NOTICE) project in order to evaluate adherence to evidence-based practices aimed at prevention of infection.

Thirty-four hemodialysis facilities were randomly selected from among 772 facilities in 4 end-stage renal disease participating networks. Facility selection was stratified on dialysis organization affiliation, size, socioeconomic status, and urban/rural status.

Trained infection control evaluators used an infection control worksheet to observe 73 distinct infection control practices at the hemodialysis facilities, from October 1, 2011, through January 31, 2012.

There was considerable variation in infection control practices across enrolled facilities. Overall adherence to recommended practices was 68% (range, 45%–92%) across all facilities. Overall adherence to expected hand hygiene practice was 72% (range, 10%–100%). Compliance to hand hygiene before and after procedures was high; however, during procedures hand hygiene compliance averaged 58%. Use of chlorhexidine as the specific agent for exit site care was 19% overall but varied from 0% to 35% by facility type. The 8 checklists varied in the frequency of perfect performance from 0% for meeting every item on the checklist for disinfection practices to 22% on the arteriovenous access practices at initiation.

Our findings suggest that there are many areas for improvement in hand hygiene and other infection prevention practices in end-stage renal disease. These NOTICE project findings will help inform the development of a larger quality improvement initiative at dialysis facilities.

Infect Control Hosp Epidemiol 2015;36(7):802–806

Infections cause morbidity and mortality in neonatal intensive care units (NICUs). The association between nursery design and nosocomial infections is unclear.

To determine whether rates of colonization by methicillin-resistant Staphylococcus aureus (MRSA), late-onset sepsis, and mortality are reduced in single-patient rooms.

Retrospective cohort study.

NICU in a tertiary referral center.

Our NICU is organized into single-patient and open-unit rooms. Clinical data sets including bed location and microbiology results were examined over 29 months. Differences in outcomes between bed configurations were determined by χ2 and Cox regression.

All NICU patients.

Among 1,823 patients representing 55,166 patient-days, single-patient and open-unit models had similar incidences of MRSA colonization and MRSA colonization-free survival times. Average daily census was associated with MRSA colonization rates only in single-patient rooms (hazard ratio, 1.31; P=.039), whereas hand hygiene compliance on room entry and exit was associated with lower colonization rates independent of bed configuration (hazard ratios, 0.834 and 0.719 per 1% higher compliance, respectively). Late-onset sepsis rates were similar in single-patient and open-unit models as were sepsis-free survival and the combined outcome of sepsis or death. After controlling for demographic, clinical, and unit-based variables, multivariate Cox regression demonstrated that bed configuration had no effect on MRSA colonization, late-onset sepsis, or mortality.

MRSA colonization rate was impacted by hand hygiene compliance, regardless of room configuration, whereas average daily census affected only infants in single-patient rooms. Single-patient rooms did not reduce the rates of MRSA colonization, late-onset sepsis, or death.

Infect Control Hosp Epidemiol 2015;36(10):1173–1182

To identify factors associated with the development of surgical site infection (SSI) among adult patients undergoing renal transplantation

A retrospective cohort study

An urban tertiary care center in Baltimore, Maryland, with a well-established renal transplantation program that performs ~200–250renal transplant procedures annually

At total of 441 adult patients underwent renal transplantation between January 1, 2010, and December 31, 2011. Of these 441patients, 66 (15%) developed an SSI; of these 66, 31 (47%) were superficial incisional infections and 35 (53%) were deep-incisional or organ-space infections. The average body mass index (BMI) among this patient cohort was 29.7; 84 (42%) were obese (BMI >30). Patients who developed an SSI had a greater mean BMI (31.7 vs 29.4; P=.004) and were more likely to have a history of peripheral vascular disease, rheumatologic disease, and narcotic abuse. History of cerebral vascular disease was protective. Multivariate analysis showed BMI (odds ratio [OR] 1.06; 95% confidence interval [CI], 1.02–1.11) and past history of narcotic use/abuse (OR, 4.86; 95% CI, 1.24–19.12) to be significantly associated with development of SSI after controlling for National Healthcare Surveillance Network (NHSN) score and presence of cerebrovascular, peripheral vascular, and rheumatologic disease.

We identified higher BMI as a risk factor for the development of SSI following renal transplantation. Notably, neither aggregate comorbidity scores nor NHSN risk index were associated with SSI in this population. Additional risk adjustment measures and research in this area are needed to compare SSIs across transplant centers.

Infect Control Hosp Epidemiol 2015;00(0): 1–7

To analyze available evidence on the effectiveness of triclosan-coated sutures (TCSs) in reducing the risk of surgical site infection (SSI).

Systematic review and meta-analysis.

A systematic search of both randomized (RCTs) and nonrandomized (non-RCT) studies was performed on PubMed Medline, OVID, EMBASE, and SCOPUS, without restrictions in language and publication type. Random-effects models were utilized and pooled estimates were reported as the relative risk (RR) ratio with 95% confidence interval (CI). Tests for heterogeneity as well as meta-regression, subgroup, and sensitivity analyses were performed.

A total of 29 studies (22 RCTs, 7 non-RCTs) were included in the meta-analysis. The overall RR of acquiring an SSI was 0.65 (95% CI: 0.55–0.77; I2=42.4%, P=.01) in favor of TCS use. The pooled RR was particularly lower for the abdominal surgery group (RR: 0.56; 95% CI: 0.41–0.77) and was robust to sensitivity analysis. Meta-regression analysis revealed that study design, in part, may explain heterogeneity (P=.03). The pooled RR subgroup meta-analyses for randomized controlled trials (RCTs) and non-RCTs were 0.74 (95% CI: 0.61–0.89) and 0.53 (95% CI: 0.42–0.66), respectively, both of which favored the use of TCSs.

The random-effects meta-analysis based on RCTs suggests that TCSs reduced the risk of SSI by 26% among patients undergoing surgery. This effect was particularly evident among those who underwent abdominal surgery.

Infect Control Hosp Epidemiol 2015;36(2): 1–11

Determine whether the NAP1 strain identified by polymerase chain reaction (PCR)-based stool assay is correlated with CDI severity and clinical outcomes.

Medical records of adult patients with positive stool Xpert® Clostridium difficile PCR assay for an initial episode of CDI between January 2012 and January 2013 at a tertiary care hospital in Chicago were reviewed. Two patients diagnosed with CDI caused by a non-NAP1 strain (positive Xpert® C. difficile assay but negative Xpert® C. difficile Epi assay) were included for each patient diagnosed with CDI caused by a NAP1 strain (positive Epi assay). Patient charts were reviewed for markers of severity, risk factors, treatment regimens, and outcomes.

Of 494 stool specimens, 90 (18%) that were positive for C. difficile by PCR were positive for NAP1 strain. In total, 37 patients with CDI due to NAP1 were matched with 74 patients with CDI due to non-NAP1 strains. Multivariable model revealed individuals ≥65 years old were 3 times more likely to have NAP1 strain than individuals <65 (P=.02). Residents of a nursing home prior to hospitalization were 10 times more likely to have NAP1 strain than patients residing in their homes (P=.001). More NAP1 cases had a change in treatment from metronidazole to oral vancomycin plus intravenous metronidazole (P=.01). The severity of CDI, incidence of mortality and recurrent CDI were similar between groups.

In a nonepidemic setting, NAP1 strains were more common in older patients and individuals admitted from nursing homes. Identification of NAP1 by PCR of stool specimens was associated in a change of therapy but did not predict worse outcomes. Reporting strain results may not be clinically useful in routine settings.

Infect Control Hosp Epidemiol 2014;00(0): 1–7

Surgical site infections (SSIs) are a leading cause of morbidity and mortality among women undergoing cesarean section (C-section), a common procedure in North America. While risk factors for SSI are often modifiable, wide variation in clinical practice exists. With this review, we provide a comprehensive overview of the results and quality of systematic reviews and meta-analyses on interventions to reduce surgical site infections among women undergoing C-section.

We searched PubMed and the Cochrane Database of Systematic Reviews for systematic reviews and meta-analyses published between January 2000 and May 2014 on interventions to reduce the occurrence of SSIs (incisional infections and endometritis), among women undergoing C-section. We extracted data on the interventions, outcomes, and strength of evidence as determined by the original article authors, and assessed the quality of each article based on a modified Assessment of Multiple Systematic Reviews tool.

A total of 30 review articles met inclusion criteria and were reviewed. Among these articles, 77 distinct interventions were evaluated: 29% were supported with strong evidence as assessed by the original article authors, and 83% of the reviews articles were classified as good quality based on our assessment. Ten interventions were classified as being effective in reducing SSI with strong evidence in a good-quality article, including preoperative vaginal cleansing, the use of perioperative antibiotic prophylaxis, and several surgical techniques.

Efforts to reduce SSI rates among women undergoing C-section should include interventions such as preoperative vaginal cleansing and the use of perioperative antibiotics because compelling evidence exists to support their effectiveness.

Infect Control Hosp Epidemiol 2015;36(8):915–921

Clostridium difficile infection (CDI) is a common hospital-acquired infection. Previous reports on the incidence, risk factors, and impact of CDI on resources in the surgical population are limited. In this context, we study CDI across diverse surgical settings.

We prospectively identified patients with laboratory-confirmed postoperative CDI after 40 different general, vascular, or gynecologic surgeries at 52 academic and community hospitals between July 2012 and September 2013. We used multivariable regression models to identify CDI risk factors and to determine the impact of CDI on resource utilization.

Of 35,363 patients, 179 (0.51%) developed postoperative CDI. The highest rates of CDI occurred after lower-extremity amputation (2.6%), followed by bowel resection or repair (0.9%) and gastric or esophageal operations (0.7%). Gynecologic and endocrine operations had the lowest rates (0.1% and 0%, respectively). By multivariable analyses, older age, chronic immunosuppression, hypoalbuminemia (≤3.5 g/dL), and preoperative sepsis were associated with CDI. Use of prophylactic antibiotics was not independently associated with CDI, neither was sex, body mass index (BMI), surgical priority, weight loss, or comorbid conditions. Three procedure groups had higher odds of postoperative CDI: lower-extremity amputations (adjusted odds ratio [aOR], 3.5; P=.03), gastric or esophageal operations (aOR, 2.1; P=.04), and bowel resection or repair (aOR, 2; P=.04). Postoperative CDI was independently associated with increased length of stay (mean, 13.7 d vs 4.5 d), emergency department presentations (18.9 vs 9.1%) and readmissions (38.9% vs 7.2%, all P<.001).

Incidence of postoperative CDI varies by surgical procedure. Postoperative CDI is also associated with higher rates of extended length of stay, emergency room presentations, and readmissions, which places a potentially preventable burden on hospital resources.

Infect Control Hosp Epidemiol 2015;36(1): 40–46