Antibiotic resistance is a major threat to public health. Resistance is largely driven by antibiotic usage, which in many cases is unnecessary and can be improved. The impact of decreasing overall antibiotic usage on resistance is unknown and difficult to assess using standard study designs. The objective of this study was to explore the potential impact of reducing antibiotic usage on the transmission of multidrug-resistant organisms (MDROs).

We used agent-based modeling to simulate interactions between patients and healthcare workers (HCWs) using model inputs informed by the literature. We modeled the effect of antibiotic usage as (1) a microbiome effect, for which antibiotic usage decreases competing bacteria and increases the MDRO transmission probability between patients and HCWs and (2) a mutation effect that designates a proportion of patients who receive antibiotics to subsequently develop a MDRO via genetic mutation.

Intensive care unit

Absolute reduction in overall antibiotic usage by experimental values of 10% and 25%

Reducing antibiotic usage absolutely by 10% (from 75% to 65%) and 25% (from 75% to 50%) reduced acquisition rates of high-prevalence MDROs by 11.2% (P<.001) and 28.3% (P<.001), respectively. We observed similar effect sizes for low-prevalence MDROs.

In a critical care setting, where up to 50% of antibiotic courses may be inappropriate, even a moderate reduction in antibiotic usage can reduce MDRO transmission.

Infect Control Hosp Epidemiol 2017;38:663–669

Peripherally inserted central catheters (PICCs) are associated with central-line–associated bloodstream infections (CLABSIs). However, no tools to predict risk of PICC-CLABSI have been developed.

To operationalize or prioritize CLABSI risk factors when making decisions regarding the use of PICCs using a risk model to estimate an individual’s risk of PICC-CLABSI prior to device placement.

Using data from the Michigan Hospital Medicine Safety consortium, patients that experienced PICC-CLABSI between January 2013 and October 2016 were identified. A Cox proportional hazards model with robust sandwich standard error estimates was then used to identify factors associated with PICC-CLABSI. Based on regression coefficients, points were assigned to each predictor and summed for each patient to create the Michigan PICC-CLABSI (MPC) score. The predictive performance of the score was assessed using time-dependent area-under-the-curve (AUC) values.

Of 23,088 patients that received PICCs during the study period, 249 patients (1.1%) developed a CLABSI. Significant risk factors associated with PICC-CLABSI included hematological cancer (3 points), CLABSI within 3 months of PICC insertion (2 points), multilumen PICC (2 points), solid cancers with ongoing chemotherapy (2 points), receipt of total parenteral nutrition (TPN) through the PICC (1 point), and presence of another central venous catheter (CVC) at the time of PICC placement (1 point). The MPC score was significantly associated with risk of CLABSI (P<.0001). For every point increase, the hazard ratio of CLABSI increased by 1.63 (95% confidence interval, 1.56–1.71). The area under the receiver-operating-characteristics curve was 0.67 to 0.77 for PICC dwell times of 6 to 40 days, which indicates good model calibration.

The MPC score offers a novel way to inform decisions regarding PICC use, surveillance of high-risk cohorts, and utility of blood cultures when PICC-CLABSI is suspected. Future studies validating the score are necessary.

Infect Control Hosp Epidemiol 2017;38:1155–1166

To estimate the incidence and identified risk factors for community-acquired (CA) and hospital-acquired (HA) Clostridium difficile infection (CDI)

We conducted 2 parallel case-control studies at Tel Aviv Sourasky Medical Center from January 1, 2011, to December 31, 2014. We identified persons with CDI, determined whether infection was community or hospital acquired, and calculated incidence rates from 2007 to 2014. We collected demographic, clinical, and epidemiological information for CDI cases and hospitalized control cases and estimated the odds ratio with 95% confidence interval using conditional logistic regression.

In total, 1,563 CDI cases were identified in the study. The incidence rate of CA-CDI and HA-CDI increased by 1.6-fold and 1.2-fold, respectively, during 2012–2014. However, the incidence rate of CA-CDI was 0.84 per 100,000 (95% CI, 0.52–1.30), the rate for HA-CDI was 4.7 per 10,000 patient days (95% CI, 4.08–5.38), respectively, in 2014. We identified several factors as independent variables significantly associated with HA-CDI: functional disability, presence of nasogastric tube, antibiotic use, chemotherapy, infection by extended-spectrum β-lactamases, and mean of albumin values. Risk factors independently associated with CA-CDI were close contact with a family member who had been hospitalized in the previous 6 months, inflammatory bowel disease, and home density index (adjusted odds ratio, 25.7; 95% confidence interval, 3.99–165.54; P=.001).

The identification of the main modifiable risk factors for HA-CDI (antibiotic exposure and hypoalbuminemia) and for CA-CDI (close contact with a family member who had been hospitalized in the previous 6 months) is likely to optimize prevention efforts; these factors are critical in preventing the spread of CDI.

Infect Control Hosp Epidemiol 2017;38:912–920

Hip and knee arthroplasty infections are associated with considerable healthcare costs. The merits of reducing the postoperative surveillance period from 1 year to 90 days have been debated.

To report the first pan-Canadian hip and knee periprosthetic joint infection (PJI) rates and to describe the implications of a shorter (90-day) postoperative surveillance period.

Prospective surveillance for infection following hip and knee arthroplasty was conducted by hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP) using standard surveillance definitions.

Overall hip and knee PJI rates were 1.64 and 1.52 per 100 procedures, respectively. Deep incisional and organ-space hip and knee PJI rates were 0.96 and 0.71, respectively. In total, 93% of hip PJIs and 92% of knee PJIs were identified within 90 days, with a median time to detection of 21 days. However, 11%–16% of deep incisional and organ-space infections were not detected within 90 days. This rate was reduced to 3%–4% at 180 days post procedure. Anaerobic and polymicrobial infections had the shortest median time from procedure to detection (17 and 18 days, respectively) compared with infections due to other microorganisms, including Staphylococcus aureus.

PJI rates were similar to those reported elsewhere, although differences in national surveillance systems limit direct comparisons. Our results suggest that a postoperative surveillance period of 90 days will detect the majority of PJIs; however, up to 16% of deep incisional and organ-space infections may be missed. Extending the surveillance period to 180 days could allow for a better estimate of disease burden.

Infect Control Hosp Epidemiol 2017;38:147–153

To identify predictors of treatment for urinary tract infections (UTI) among patients undergoing total hip (THA) or knee (TKA) arthroplasties and to assess an intervention based on these predictors.

We conducted a retrospective cohort study of 200 consecutive patients undergoing THA/TKA between February 21, 2011, and June 30, 2011, to identify predictors of treatment for UTI and a prospective cohort study of 50 patients undergoing these procedures between May 21, 2012, and July 17, 2012, to assess the association of signs or symptoms and UTI treatment. We then conducted a before-and-after study to assess whether implementing an intervention affected the frequency of treatment for UTI before or after THA/TKA.

The orthopedics department of a university health center.

Patients undergoing THA or TKA.

Surgeons revised their UTI screening and treatment practices.

Positive leukocyte esterase (P<.0001; P<.0001) and urine white blood cell count>5 (P=.01; P=.01) were associated with preoperative or postoperative UTI treatment. In the prospective study, 12 patients (24%) had signs and symptoms consistent with UTI. The number of patients treated for presumed UTI decreased 80.2% after the surgeons changed their practices, and surgical site infection (SSI) rates, including prosthetic joint infections (PJIs), did not increase.

Urine leukocyte esterase and white blood cell count were the strongest predictors of treatment for UTI before or after THA/TKA. The intervention was associated with a significant decrease in treatment for UTI, and SSI/PJI rates did not increase.

Infect Control Hosp Epidemiol 2017;38:281–286

To evaluate host characteristics, mode of infection acquisition, and infection control procedures in patients with a positive respiratory syncytial virus (RSV) test result after the introduction of the GenXpert Influenza/RSV polymerase chain reaction (PCR) assay.

Retrospective cohort study.

Adults with a positive PCR test result for RSV who were hospitalized in a tertiary academic medical center between January 2015 and December 2016 were included in this study. Our infection control policy applies contact isolation precautions only for immunocompromised patients.

Patients were identified through 2 databases, 1 consisting of patients isolated because of RSV infection and 1 with automatically collected laboratory results. Baseline and clinical characteristics were collected through a retrospective medical chart review. The rate of and clinical factors associated with healthcare-associated RSV infections were evaluated.

In total, 108 episodes in 106 patients hospitalized with a positive Xpert RSV test result were recorded during the study period. Among them, 11 episodes were healthcare-associated infections (HAIs) and 97 were community-acquired infections (CAIs). The mean length of hospital stay (LOS, 40.2 vs 11.2 days), the mean number of room switches (3.5 vs 1.7) and ward switches (1.5 vs 0.4), and the mean numbers of contact patients (9.9 vs 3.8) were significantly longer and higher in the HAI group than in the CAI group (P<.0001). Surveillance of microbiology records and clinical data did not reveal evidence for a cluster or an epidemic during the 2-year observation period.

The introduction of a rapid molecular diagnostic test systematically applied to patients with influenza-like illness may challenge current infection control policies. In our study, patients with HAIs had a prolonged hospital stay and a high number of contact patients, and they switched rooms and wards frequently.

Infect Control Hosp Epidemiol 2017;38:1291–1297

To describe the investigation and control of a cluster of Serratia marcescens bacteremia in a 505-bed tertiary-care center.

Cluster cases were defined as all patients with S. marcescens bacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio.

In total, 6 patients developed S. marcescens bacteremia within 48 hours after admission within the above period. Of these, 5 patients had identical Serratia isolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employee’s job was terminated.

Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting.

Infect Control Hosp Epidemiol 2017;38:1027–1031

To assess resource allocation and costs associated with US hospitals preparing for the possible spread of the 2014–2015 Ebola virus disease (EVD) epidemic in the United States.

A survey was sent to a stratified national probability sample (n=750) of US general medical/surgical hospitals selected from the American Hospital Association (AHA) list of hospitals. The survey was also sent to all children’s general hospitals listed by the AHA (n=60). The survey assessed EVD preparation supply costs and overtime staff hours. The average national wage was multiplied by labor hours to calculate overtime labor costs. Additional information collected included challenges, benefits, and perceived value of EVD preparedness activities.

The average amount spent by hospitals on combined supply and overtime labor costs was $80,461 (n=133; 95% confidence interval [CI], $56,502–$104,419). Multivariate analysis indicated that small hospitals (mean, $76,167) spent more on staff overtime costs per 100 beds than large hospitals (mean, $15,737; P<.0001). The overall cost for acute-care hospitals in the United States to prepare for possible EVD cases was estimated to be $361,108,968. The leading challenge was difficulty obtaining supplies from vendors due to shortages (83%; 95% CI, 78%–88%) and the greatest benefit was improved knowledge about personal protective equipment (89%; 95% CI, 85%–93%).

The financial impact of EVD preparedness activities was substantial. Overtime cost in smaller hospitals was >3 times that in larger hospitals. Planning for emerging infectious disease identification, triage, and management should be conducted at regional and national levels in the United States to facilitate efficient and appropriate allocation of resources in acute-care facilities.

Infect Control Hosp Epidemiol 2017;38:405–410

To evaluate the impact of early infectious diseases (ID) antimicrobial stewardship (AMS) intervention on inpatient sepsis antibiotic management.

Interventional, nonrandomized, controlled study.

Tertiary-care referral hospital, Sydney, Australia.

Consecutive, adult, non–intensive care unit (non-ICU) inpatients triggering an institutional clinical sepsis pathway from May to August 2015.

All patients reviewed by an ID Fellow within 24 hours of sepsis pathway trigger underwent case review and clinic file documentation of recommendations. Those not reviewed by an ID Fellow were considered controls and received standard sepsis pathway care. The primary outcome was antibiotic appropriateness 48 hours after sepsis trigger.

In total, 164 patients triggered the sepsis pathway: 6 patients were excluded (previous sepsis trigger); 158 patients were eligible; 106 had ID intervention; and 52 were control cases. Of these 158 patients, 91 (58%) had sepsis, and 15 of these 158 (9.5%) had severe sepsis. Initial antibiotic appropriateness, assessable in 152 of 158 patients, was appropriate in 80 (53%) of these 152 patients and inappropriate in 72 (47%) of these patients. In the intervention arm, 93% of ID Fellow recommendations were followed or partially followed, including 53% of cases in which antibiotics were de-escalated. ID Fellow intervention improved antibiotic appropriateness at 48 hours by 24% (adjusted risk ratio, 1.24; 95% confidence interval, 1.04–1.47; P=.035). The appropriateness agreement among 3 blinded ID staff opinions was 95%. Differences in intervention and control group mortality (13% vs 17%) and median length of stay (13 vs 17.5 days) were not statistically significant.

Sepsis overdiagnosis and delayed antibiotic optimization may reduce sepsis pathway effectiveness. Early ID AMS improved antibiotic management of non-ICU inpatients with suspected sepsis, predominantly by de-escalation. Further studies are needed to evaluate clinical outcomes.

Infect Control Hosp Epidemiol 2017;38:1032–1038

In 2011, pediatric hematopoietic stem cell transplant (HSCT) patients were moved from an older hospital to a new children’s hospital. To minimize bacterial growth in the new hospital’s water during construction, the plumbing system was flushed and disinfected before occupancy. However, 6 months after occupancy, an increased incidence of rapidly growing mycobacteria (RGM) was detected in clinical cultures. Over 10 months, 15 pediatric HSCT patients were infected, while no pediatric HSCT patients had been infected in the preceding 12 months.

To determine the cause of the outbreak and to interrupt patient acquisition of RGM.

Water samples were collected from water entering the hospital and from drinking water and ice machines (DWIMs) from the old and new hospitals. Total heterotrophic plate counts (HPCs, CFU/mL) of water were undertaken, and select isolates were identified as RGM.

The cause of the outbreak was increased bacterial levels in the water (including RGM) in the DWIMs in the new (2011) hospital. Tests revealed higher HPCs in drinking water and ice from the DWIMs in the new hospital than in the DWIMs in the old hospital. Ultimately, HPCs were reduced by several different interventions.

In response to an RGM outbreak, HSCT patients were banned from ingesting DWIM ice and water and bottled water was provided. Since this interverntion 4 years ago, no additional RGM isolates have been identified in HSCT patient cultures. Our measures to reduce HPCs to goal levels in drinking water from DWIMs were successful, but the HPCs for ice have not consistently reached the goal of <500 CFU/mL.

Infect Control Hosp Epidemiol 2017;38:792–800

To assess clinically relevant outcomes after complete cessation of control measures for vancomycin-resistant enterococci (VRE).

Quasi-experimental ecological study over 3.5 years.

All VRE screening and isolation practices at 4 large academic hospitals in Ontario, Canada, were stopped on July 1, 2012. In total, 618 anonymized abstracted charts of patients with VRE-positive clinical isolates identified between July 1, 2010, and December 31, 2013, were reviewed to determine whether the case was a true VRE infection, a VRE colonization or contaminant, or a true VRE bacteremia. All deaths within 30 days of the last VRE infection were also reviewed to determine whether the death was fully or partially attributable to VRE. All-cause mortality was evaluated over the study period. Generalized estimating equation methods were used to cluster outcome rates within hospitals, and negative binomial models were created for each outcome.

The incidence rate ratio (IRR) for VRE infections was 0.59 and the associated P value was .34. For VRE bacteremias, the IRR was 0.54 and P=.38; for all-cause mortality the IRR was 0.70 and P=.66; and for VRE attributable death, the IRR was 0.35 and P=.49. VRE control measures were not significantly associated with any of the outcomes. Rates of all outcomes appeared to increase during the 18-month period after cessation of VRE control measures, but none reached statistical significance.

Clinically significant VRE outcomes remain rare. Cessation of all control measures for VRE had no significant attributable adverse clinical impact.

Infect Control Hosp Epidemiol 2016;1–7

To explore the frequency of hand hygiene opportunities (HHOs) in multiple units of an acute-care hospital.

Prospective observational study.

The adult intensive care unit (ICU), medical and surgical step-down units, medical and surgical units, and the postpartum mother–baby unit (MBU) of an academic acute-care hospital during May–August 2013, May–July 2014, and June–August 2015.

Healthcare workers (HCWs).

HHOs were recorded using direct observation in 1-hour intervals following Public Health Ontario guidelines. The frequency and distribution of HHOs per patient hour were determined for each unit according to time of day, indication, and profession.

In total, 3,422 HHOs were identified during 586 hours of observation. The mean numbers of HHOs per patient hour in the ICU were similar to those in the medical and surgical step-down units during the day and night, which were higher than the rates observed in medical and surgical units and the MBU. The rate of HHOs during the night significantly decreased compared with day (P<.0001). HHOs before an aseptic procedure comprised 13% of HHOs in the ICU compared with 4%–9% in other units. Nurses contributed >92% of HHOs on medical and surgical units, compared to 67% of HHOs on the MBU.

Assessment of hand hygiene compliance using product utilization data requires knowledge of the appropriate opportunities for hand hygiene. We have provided a detailed characterization of these estimates across a wide range of inpatient settings as well as an examination of temporal variations in HHOs.

Infect Control Hosp Epidemiol 2017;38:411–416

For alcohol-based hand rubs, the currently recommended application time of 30 seconds is longer than the actual time spent in clinical practice. We investigated whether a shorter application time of 15 seconds is microbiologically safe in neonatal intensive care and may positively influence compliance with the frequency of hand antisepsis actions.

We conducted in vitro experiments to determine the antimicrobial efficacy of hand rubs within 15 seconds, followed by clinical observations to assess the effect of a shortened hand antisepsis procedure under clinical conditions in a neonatal intensive care unit (NICU). An independent observer monitored the frequency of hand antisepsis actions during shifts.

All tested hand rubs fulfilled the requirement of equal or even significantly higher efficacy within 15 seconds when compared to a reference alcohol propan-2-ol 60% (v/v) within 30 seconds. Microbiologically, reducing the application time to 15 seconds had a similar effect when compared to 30-second hand rubbing, but it resulted in significantly increased frequency of hand antisepsis actions (7.9±4.3 per hour vs 5.8±2.9 per hour; P=.05).

Time pressure and workload are recognized barriers to compliance. Therefore, reducing the recommended time for hand antisepsis actions, using tested and well-evaluated hand rub formulations, may improve hand hygiene compliance in clinical practice.

Infect Control Hosp Epidemiol 2017;38:1430–1434

Surveillance is an important strategy to reduce the incidence of surgical site infections (SSIs). We investigated whether prior, multiple-, or repetitive surgeries are risk factors for SSI and whether they should be preserved in the protocol of the Dutch national SSI surveillance network.

Dutch national SSI surveillance data 2012–2015 were selected, including 34 commonly performed procedures from 8 major surgical specialties. Definitions of SSIs followed international standardized criteria. We used multivariable multilevel logistic regression techniques to evaluate whether prior, multiple-, or repetitive procedure(s) are risk factors for SSIs. We considered surgeries clustered within partnerships of medical specialists and within hospitals (random effects) and different baseline risks between surgical specialties (fixed effects). Several patient and surgical characteristics were considered possible confounders and were included where necessary. We performed analyses for superficial and deep SSIs combined as well as separately.

In total, 115,943 surgeries were reported by 85 hospitals; among them, 2,960 (2.6%) resulted in SSIs (49.3% deep SSIs). The odds ratio (OR) for having prior surgery was 0.94 (95% confidence interval [CI], 0.74–1.20); the OR for repetitive surgery was 2.39 (95% CI, 2.06–2.77); and the OR for multiple surgeries was1.27 (95% CI, 1.07–1.51). The latter effect was mainly caused by prolonged duration of surgery.

Multiple- and repetitive surgeries significantly increased the risk of an SSI, whereas prior surgery did not. Therefore, prior surgery is not an essential data item to include in the national SSI surveillance network. The increased risk of SSIs for multiple surgeries was mainly caused by prolonged duration of surgery, therefore, it may be sufficient to report only duration of surgery to the surveillance network, instead of both (the variables duration of surgery and multiple surgeries).

Infect Control Hosp Epidemiol 2017;38:1298–1305

For most common infections requiring hospitalization, antibiotic treatment is completed after hospital discharge. Postdischarge therapy is often unnecessarily broad spectrum and prolonged. We developed an intervention to improve antibiotic selection and shorten treatment durations.

Single center, quasi-experimental retrospective cohort study

Patients prescribed oral antibiotics at hospital discharge before (July 2012–June 2013) and after (October 2014–February 2015) an intervention consisting of (1) institutional guidance for oral step-down antibiotic selection and duration of therapy and (2) pharmacy audit of discharge prescriptions with real-time prescribing recommendations to providers. The primary outcomes measured were total prescribed duration of therapy and use of antibiotics with broad gram-negative activity (ie, fluoroquinolones or amoxicillin-clavulanate).

Overall, 300 cases from the preintervention period and 200 cases from the intervention period were included. Compared with the preintervention period, the use of antibiotics with broad gram-negative activity decreased during the intervention (51% vs 40%; P=.02), particularly fluoroquinolones (38% vs 25%; P=.002). The total duration of therapy decreased from a median of 10 days (interquartile range [IQR], 7–13 days) to 9 days (IQR, 6–13 days) but did not reach statistical significance (P=.13). However, the duration prescribed at discharge declined from 6 days (IQR, 4–10 days) to 5 days (IQR, 3–7 days) (P=.003). During the intervention, there was a nonsignificant increase in the overall appropriateness of discharge prescriptions from 52% to 66% (P=.15).

A multifaceted intervention to optimize antibiotic prescribing at hospital discharge was associated with less frequent use of antibiotics with broad gram-negative activity and shorter postdischarge treatment durations.

Infect Control Hosp Epidemiol 2017;38:534–541

The impact of healthcare system integration on infection prevention programs is unknown. Using catheter-associated urinary tract infection (CAUTI) prevention as an example, we hypothesize that US Department of Veterans Affairs (VA) nursing homes have a more robust infection prevention infrastructure due to integration and centralization compared with non–VA nursing homes.

VA and non-VA nursing homes participating in the AHRQ Safety Program for Long-Term Care collaborative.

Nursing homes provided baseline information about their infection prevention programs to assess strengths and gaps related to CAUTI prevention via a needs assessment questionnaire.

A total of 353 of 494 nursing homes from 41 states (71%; 47 VA and 306 non-VA facilities) responded. VA nursing homes reported more hours per week devoted to infection prevention-related activities (31 vs 12 hours; P<.001) and were more likely to have committees that reviewed healthcare-associated infections. Compared with non-VA facilities, a higher percentage of VA nursing homes reported tracking CAUTI rates (94% vs 66%; P<.001), sharing CAUTI data with leadership (94% vs 70%; P=.014) and with nursing personnel (85% vs 56%, P=.003). However, fewer VA nursing homes reported having policies for appropriate catheter use (64% vs 81%; P=.004) and catheter insertion (83% vs 94%; P=.004).

Among nursing homes participating in an AHRQ-funded collaborative, VA and non-VA nursing homes differed in their approach to CAUTI prevention. Best practices from both settings should be applied universally to create an optimal infection prevention program within emerging integrated healthcare systems.

Infect Control Hosp Epidemiol 2017;38:287–293

To determine whether patients using the Centers for Medicare and Medicaid Services (CMS) Hospital Compare website (http://medicare.gov/hospitalcompare) can use nationally reported healthcare-associated infection (HAI) data to differentiate hospitals.

Secondary analysis of publicly available HAI data for calendar year 2013.

We assessed the availability of HAI data for geographically proximate hospitals (ie, hospitals within the same referral region) and then analyzed these data to determine whether they are useful to differentiate hospitals. We assessed data for the 6 HAIs reported by hospitals to the Centers for Disease Control and Prevention (CDC).

Data were analyzed for 4,561 hospitals representing 88% of registered community and federal government hospitals in the United States. Healthcare-associated infection data are only useful for comparing hospitals if they are available for multiple hospitals within a geographic region. We found that data availability differed by HAI. Clostridium difficile infections (CDI) data were most available, with 82% of geographic regions (ie, hospital referral regions) having >50% of hospitals reporting them. In contrast, 4% of geographic regions had >50% of member hospitals reporting surgical site infections (SSI) for hysterectomies, which had the lowest availability. The ability of HAI data to differentiate hospitals differed by HAI: 72% of hospital referral regions had at least 1 pair of hospitals with statistically different risk-adjusted CDI rates (SIRs), compared to 9% for SSI (hysterectomy).

HAI data generally are reported by enough hospitals to meet minimal criteria for useful comparisons in many geographic locations, though this varies by type of HAI. CDI and catheter-associated urinary tract infection (CAUTI) are more likely to differentiate hospitals than the other publicly reported HAIs.

Infect Control Hosp Epidemiol 2017;38:1167–1171

We aimed to clarify whether invasive dental treatment is associated with increased risk of prosthetic joint infection (PJI) and whether prophylactic antibiotics may lower the infection risk remain unclear.

Retrospective cohort study.

All Taiwanese residents (N=255,568) who underwent total knee or hip arthroplasty between January 1, 1997, and November 30, 2009, were screened.

The dental cohort consisted of 57,066 patients who received dental treatment and were individually matched 1:1 with the nondental cohort by age, sex, propensity score, and index date. The dental cohort was further divided by the use or nonuse of prophylactic antibiotics. The antibiotic and nonantibiotic subcohorts comprised 6,513 matched pairs.

PJI occurred in 328 patients (0.57%) in the dental subcohort and 348 patients (0.61%) in the nondental subcohort, with no between-cohort difference in the 1-year cumulative incidence (0.6% in both, P=.3). Multivariate-adjusted Cox regression revealed no association between dental procedures and PJI. Furthermore, PJI occurred in 13 patients (0.2%) in the antibiotic subcohort and 12 patients (0.18%) in the nonantibiotic subcohorts (P=.8). Multivariate-adjusted analyses confirmed that there was no association between the incidence of PJI and prophylactic antibiotics.

The risk of PJI is not increased following dental procedure in patients with hip or knee replacement and is unaffected by antibiotic prophylaxis.

Infect Control Hosp Epidemiol. 2017;38:154–161

Carbapenem-resistant Enterobacteriaceae (CRE) are a significant clinical and public health concern. Understanding the distribution of CRE colonization and developing a coordinated approach are key components of control efforts. The prevalence of CRE in the District of Columbia is unknown. We sought to determine the CRE colonization prevalence within healthcare facilities (HCFs) in the District of Columbia using a collaborative, regional approach.

Point-prevalence study.

This study included 16 HCFs in the District of Columbia: all 8 acute-care hospitals (ACHs), 5 of 19 skilled nursing facilities, 2 (both) long-term acute-care facilities, and 1 (the sole) inpatient rehabilitation facility.

Inpatients on all units excluding psychiatry and obstetrics-gynecology.

CRE identification was performed on perianal swab samples using real-time polymerase chain reaction, culture, and antimicrobial susceptibility testing (AST). Prevalence was calculated by facility and unit type as the number of patients with a positive result divided by the total number tested. Prevalence ratios were compared using the Poisson distribution.

Of 1,022 completed tests, 53 samples tested positive for CRE, yielding a prevalence of 5.2% (95% CI, 3.9%–6.8%). Of 726 tests from ACHs, 36 (5.0%; 95% CI, 3.5%–6.9%) were positive. Of 244 tests from long-term-care facilities, 17 (7.0%; 95% CI, 4.1%–11.2%) were positive. The relative prevalence ratios by facility type were 0.9 (95% CI, 0.5–1.5) and 1.5 (95% CI, 0.9–2.6), respectively. No CRE were identified from the inpatient rehabilitation facility.

A baseline CRE prevalence was established, revealing endemicity across healthcare settings in the District of Columbia. Our study establishes a framework for interfacility collaboration to reduce CRE transmission and infection.

Infect Control Hosp Epidemiol 2017;38:921–929

To identify modifiable risk factors for acquisition of Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (KPC) colonization among long-term acute-care hospital (LTACH) patients.

Multicenter, matched case-control study.

Four LTACHs in Chicago, Illinois.

Each case patient included in this study had a KPC-negative rectal surveillance culture on admission followed by a KPC-positive surveillance culture later in the hospital stay. Each matched control patient had a KPC-negative rectal surveillance culture on admission and no KPC isolated during the hospital stay.

From June 2012 to June 2013, 2,575 patients were admitted to 4 LTACHs; 217 of 2,144 KPC-negative patients (10.1%) acquired KPC. In total, 100 of these patients were selected at random and matched to 100 controls by LTACH facility, admission date, and censored length of stay. Acquisitions occurred a median of 16.5 days after admission. On multivariate analysis, we found that exposure to higher colonization pressure (OR, 1.02; 95% CI, 1.01–1.04; P=.002), exposure to a carbapenem (OR, 2.25; 95% CI, 1.06–4.77; P=.04), and higher Charlson comorbidity index (OR, 1.14; 95% CI, 1.01–1.29; P=.04) were independent risk factors for KPC acquisition; the odds of KPC acquisition increased by 2% for each 1% increase in colonization pressure.

Higher colonization pressure, exposure to carbapenems, and a higher Charlson comorbidity index independently increased the odds of KPC acquisition among LTACH patients. Reducing colonization pressure (through separation of KPC-positive patients from KPC-negative patients using strict cohorts or private rooms) and reducing carbapenem exposure may prevent KPC cross transmission in this high-risk patient population.

Infect Control Hosp Epidemiol 2017;38:670–677