Because antibacterial history is difficult to obtain, especially when the exposure occurred at an outside hospital, we assessed whether infection-related diagnostic billing codes, which are more readily available through hospital discharge databases, could infer prior antibacterial receipt.

Retrospective cohort study.

This study included 121,916 hospitalizations representing 78,094 patients across the 3 hospitals.

We obtained hospital inpatient data from 3 Chicago-area hospitals. Encounters were categorized as “infection” if at least 1 International Classification of Disease, Ninth Revision, Clinical Modification (ICD-9-CM) code indicated a bacterial infection. From medication administration records, we categorized antibacterial agents and calculated total therapy days using Centers for Disease Control and Prevention (CDC) definitions. We evaluated bivariate associations between infection encounters and 3 categories of antibacterial exposure: any, broad spectrum, or surgical prophylaxis. We constructed multivariable models to evaluate adjusted risk ratios for antibacterial receipt.

Of the 121,916 inpatient encounters (78,094 patients) across the 3 hospitals, 24% had an associated infection code, 47% received an antibacterial, and 13% received a broad-spectrum antibacterial. Infection-related ICD-9-CM codes were associated with a 2-fold increase in antibacterial administration compared to those lacking such codes (RR, 2.29; 95% confidence interval [CI], 2.27–2.31) and a 5-fold increased risk for broad-spectrum antibacterial administration (RR, 5.52; 95% CI, 5.37–5.67). Encounters with infection codes had 3 times the number of antibacterial days.

Infection diagnostic billing codes are strong surrogate markers for prior antibacterial exposure, especially to broad-spectrum antibacterial agents; such an association can be used to enhance early identification of patients at risk of multidrug-resistant organism (MDRO) carriage at the time of admission.

Infect Control Hosp Epidemiol 2018;39:377–382

The decision to utilize antimicrobials in end-of-life situations is complex. Understanding the reasons why physicians prescribe antimicrobials in this patient population is important for informing the design of antimicrobial stewardship interventions.

A 51-item survey containing both closed and open-ended questions on end-of-life antimicrobial use was administered to physicians affiliated with the University of Pennsylvania and Children’s Hospital of Philadelphia from January through April 2017. A mixed-methods approach was used to analyze responses.

Of 637 physicians surveyed, 283 responses (44.4%) were received. Most (86.2%) physicians believed that respecting a patient’s wish to continue antimicrobials was important. Approximately half of physicians (49.8%) believed that antimicrobial use at the end of life contributes to resistance. A higher proportion of pediatricians would often or always continue antimicrobial treatment for active infections and for hospice patients whose death was imminent compared to adult physicians (P<.001). Analysis of free-text responses revealed additional reasons why physicians may continue antimicrobials at end of life, including meeting family expectations, wanting to avoid the perception of “giving up,” uncertainty about prognosis, and reducing patient pain or discomfort.

Physician decision making concerning antimicrobial use in patients at the end of life is multifactorial. Clinicians may overweigh the benefits of antimicrobial therapy in end-of-life situations and view the importance of adhering to stewardship policies differently. Pediatric and adult clinicians have different approaches to this patient population. Better understanding of the complex decision making that occurs in the end-of-life patient population can help guide antimicrobial stewardship policies and improve patient care.

Infect Control Hosp Epidemiol 2018;39:383–390

To determine how the movement of patients, equipment, materials, staff, and door openings within the operating room (OR) affect microbial loads at various locations within the OR.

Observation and sampling study.

Academic health center, public hospital.

We first analyzed 27 videotaped procedures to determine the areas in the OR with high and low numbers of people in transit. We then placed air samplers and settle plates in representative locations during 21 procedures in 4 different ORs during 2 different seasons of the year to measure microbial load in colony-forming units (CFU). The temperature and humidity, number of door openings, physical movement, and the number of people in the OR were measured for each procedure. Statistical analysis was conducted using hierarchical regression.

The microbial load was affected by the time of year that the samples were taken. Both microbial load measured by the air samplers and by settle plates in 1 area of the OR was correlated with the physical movement of people in the same area but not with the number of door openings and the number of people in the OR.

Movement in the OR is correlated with the microbial load. Establishing operational guidelines or developing OR layouts that focus on minimizing movement by incorporating desirable internal storage points and workstations can potentially reduce microbial load, thereby potentially reducing surgical site infection risk.

Infect Control Hosp Epidemiol 2018;39:391–397

The healthcare environment is recognized as a source for healthcare-acquired infection. Because cleaning practices are often erratic and always intermittent, we hypothesize that continuously antimicrobial surfaces offer superior control of surface bioburden.

To evaluate the impact of a photocatalytic antimicrobial coating at near-patient, high-touch sites in a hospital ward.

The study took place in 2 acute-care wards in a large acute-care hospital.

A titanium dioxide-based photocatalytic coating was sprayed onto 6 surfaces in a 4-bed bay in a ward and compared under normal illumination against the same surfaces in an untreated ward: right and left bed rails, bed control, bedside locker, overbed table, and bed footboard. Using standardized methods, the overall microbial burden and presence of an indicator pathogen (Staphylococcus aureus) were assessed biweekly for 12 weeks.

Treated surfaces demonstrated significantly lower microbial burden than control sites, and the difference increased between treated and untreated surfaces during the study. Hygiene failures (>2.5 colony-forming units [CFU]/cm2) increased 2.6% per day for control surfaces (odds ratio [OR], 1.026; 95% confidence interval [CI], 1.009–1.043; P=.003) but declined 2.5% per day for treated surfaces (OR, 0.95; 95% CI, 0.925–0.977; P<.001). We detected no significant difference between coated and control surfaces regarding S. aureus contamination.

Photocatalytic coatings reduced the bioburden of high-risk surfaces in the healthcare environment. Treated surfaces became steadily cleaner, while untreated surfaces accumulated bioburden. This evaluation encourages a larger-scale investigation to ascertain whether the observed environmental amelioration has an effect on healthcare-acquired infection.

Infect Control Hosp Epidemiol 2018;39:398–404

Bathing intensive care unit (ICU) patients with 2% chlorhexidine gluconate (CHG)–impregnated cloths decreases the risk of healthcare-associated bacteremia and multidrug-resistant organism transmission. Hospitals employ different methods of CHG bathing, and few studies have evaluated whether those methods yield comparable results.

To determine whether 3 different CHG skin cleansing methods yield similar residual CHG concentrations and bacterial densities on skin.

Prospective, randomized 2-center study with blinded assessment.

Healthcare personnel in surgical ICUs at 2 tertiary-care teaching hospitals in Chicago, Illinois, and Boston, Massachusetts, from July 2015 to January 2016.

Cleansing skin of one forearm with no-rinse 2% CHG-impregnated polyester cloth (method A) versus 4% CHG liquid cleansing with rinsing on the contralateral arm, applied with either non–antiseptic-impregnated cellulose/polyester cloth (method B) or cotton washcloth dampened with sterile water (method C).

In total, 63 participants (126 forearms) received method A on 1 forearm (n=63). On the contralateral forearm, 33 participants received method B and 30 participants received method C. Immediately and 6 hours after cleansing, method A yielded the highest residual CHG concentrations (2500 µg/mL and 1250 µg/mL, respectively) and lowest bacterial densities compared to methods B or C (P<.001).

In healthy volunteers, cleansing with 2% CHG-impregnated cloths yielded higher residual CHG concentrations and lower bacterial densities than cleansing with 4% CHG liquid applied with either of 2 different cloth types and followed by rinsing. The relevance of these differences to clinical outcomes remains to be determined.

Infect Control Hosp Epidemiol 2018;39:405–411

Clostridium difficile infection (CDI) presents a substantial economic burden and is associated with significant morbidity. While multiple treatment strategies have been evaluated, a cost-effective management strategy remains unclear.

We conducted a systematic review to assess cost-effectiveness analyses of CDI treatment and to summarize key issues for clinicians and policy makers to consider.

We searched PubMed and 5 other databases from inception to August 2016. These searches were not limited by study design or language of publication. Two reviewers independently screened the literature, abstracted data, and assessed methodological quality using the Drummond and Jefferson checklist. We extracted data on study characteristics, type of CDI, treatment characteristics, and model structure and inputs.

We included 14 studies, and 13 of these were from high-income countries. More than 90% of these studies were deemed moderate-to-high or high quality. Overall, 6 studies used a decision-tree model and 7 studies used a Markov model. Cost of therapy, time horizon, treatment cure rates, and recurrence rates were common influential factors in the study results. For initial CDI, fidaxomicin was a more cost-effective therapy than metronidazole or vancomycin in 2 of 3 studies. For severe initial CDI, 2 of 3 studies found fidaxomicin to be the most cost-effective therapy. For recurrent CDI, fidaxomicin was cost-effective in 3 of 5 studies, while fecal microbiota transplantation (FMT) by colonoscopy was consistently cost-effective in 4 of 4 studies.

The cost-effectiveness of fidaxomicin compared with other pharmacologic therapies was not definitive for either initial or recurrent CDI. Despite its high cost, FMT by colonoscopy may be a cost-effective therapy for recurrent CDI. A consensus on model design and assumptions are necessary for future comparison of CDI treatment.

Infect Control Hosp Epidemiol 2018;39:412–424

An estimated 293,300 healthcare-associated cases of Clostridium difficile infection (CDI) occur annually in the United States. To date, research has focused on developing risk prediction models for CDI that work well across institutions. However, this one-size-fits-all approach ignores important hospital-specific factors. We focus on a generalizable method for building facility-specific models. We demonstrate the applicability of the approach using electronic health records (EHR) from the University of Michigan Hospitals (UM) and the Massachusetts General Hospital (MGH).

We utilized EHR data from 191,014 adult admissions to UM and 65,718 adult admissions to MGH. We extracted patient demographics, admission details, patient history, and daily hospitalization details, resulting in 4,836 features from patients at UM and 1,837 from patients at MGH. We used L2 regularized logistic regression to learn the models, and we measured the discriminative performance of the models on held-out data from each hospital.

Using the UM and MGH test data, the models achieved area under the receiver operating characteristic curve (AUROC) values of 0.82 (95% confidence interval [CI], 0.80–0.84) and 0.75 ( 95% CI, 0.73–0.78), respectively. Some predictive factors were shared between the 2 models, but many of the top predictive factors differed between facilities.

A data-driven approach to building models for estimating daily patient risk for CDI was used to build institution-specific models at 2 large hospitals with different patient populations and EHR systems. In contrast to traditional approaches that focus on developing models that apply across hospitals, our generalizable approach yields risk-stratification models tailored to an institution. These hospital-specific models allow for earlier and more accurate identification of high-risk patients and better targeting of infection prevention strategies.

Infect Control Hosp Epidemiol 2018;39:425–433

The impact of storage on stability and detection of Clostridium difficile toxins in feces is poorly understood. The objective of this study was to investigate the immunological stability of C. difficile toxins in clinical stool specimens under different storage conditions by evaluating this stability using toxin detection by enzyme immunoassay (EIA).

Stool specimens positive for C. difficile infection (CDI) by quantitative polymerase chain reaction (qPCR) were used for EIA testing with the C. difficile Tox A/B II kit. The EIA-positive specimens were stored aerobically under refrigerated (4–10°C) and frozen (−30°C and −80°C) conditions. Measurement of toxin quantity was conducting using optical density (OD) on days 0, 14, 30, 60, 90, and 120 of storage.

Clostridium difficile toxins demonstrated good detection in undiluted stool specimens by EIA up to 120 days of storage. Good detection of the toxins was observed in diluted samples at refrigerated and −80°C temperatures. Dilution detrimentally affected toxin detection at −30°C.

Storage of undiluted clinical stool specimens at refrigerated, −30°C, and −80°C temperatures for up to 120 days has no discernible effect on the immunological stability of C. difficile cytotoxins. However, storage at −30°C has a detrimental effect on C. difficile toxin stability in diluted specimens.

Infect Control Hosp Epidemiol 2018;39:434–438

Outpatient central venous catheters (CVCs) are being used more frequently; however, data describing mechanical complications and central-line–associated bloodstream infections (CLABSI) in the outpatient setting are limited. We performed a retrospective observational cohort study to understand the burden of these complications to elucidate their impact on the healthcare system.

Data were retrospectively collected on patients discharged from Vanderbilt University Medical Center with a CVC in place and admitted into the care of Vanderbilt Home Care Services. Risk factors for medically attended catheter-associated complications (CACs) and outpatient CLABSIs were analyzed.

A CAC developed in 143 patients (21.9%), for a total of 165 discrete CAC events. Among these, 76 (46%) required at least 1 visit to the emergency department or an inpatient admission, while the remaining 89 (54%) required an outpatient clinic visit. The risk for developing a CAC was significantly increased in female patients, patients with a CVC with >1 lumen, and patients receiving total parenteral nutrition. The absolute number of CLABSIs identified in the study population was small at 16, or 2.4% of the total cohort.

Medically attended catheter complications were common among outpatients discharged with a CVC, and reduction of these events should be the focus of outpatient quality improvement programs.

Infect Control Hosp Epidemiol 2018;39:439–444

To analyze the impact of the International Nosocomial Infection Control Consortium (INICC) Multidimensional Approach (IMA) and the INICC Surveillance Online System (ISOS) on central line-associated bloodstream infection (CLABSI) rates in 14 intensive care units (ICUs) in Argentina from January 2014 to April 2017.

This prospective, pre–post surveillance study of 3,940 ICU patients was conducted in 11 hospitals in 5 cities in Argentina. During our baseline evaluation, we performed outcome and process surveillance of CLABSI applying Centers for Disease Control and Prevention/National Health Safety Network (CDC/NHSN) definitions. During the intervention, we implemented the IMA through ISOS: (1) a bundle of infection prevention practice interventions, (2) education, (3) outcome surveillance, (4) process surveillance, (5) feedback on CLABSI rates and consequences, and (6) performance feedback of process surveillance. Bivariate and multivariate regression analyses were performed using a logistic regression model to estimate the effect of the intervention on the CLABSI rate.

During the baseline period, 5,118 CL days and 49 CLABSIs were recorded, for a rate of 9.6 CLABSIs per 1,000 central-line (CL) days. During the intervention, 15,659 CL days and 68 CLABSIs were recorded, for a rate of 4.1 CLABSIs per 1,000 CL days. The CLABSI rate was reduced by 57% (incidence density rate: 0.43; 95% confidence interval, 0.34–0.6; P<.001).

Implementing IMA through ISOS was associated with a significant reduction in the CLABSI rate in ICUs in Argentina.

Infect Control Hosp Epidemiol 2018;39:445–451

To determine the effect of mandatory and nonmandatory influenza vaccination policies on vaccination rates and symptomatic absenteeism among healthcare personnel (HCP).

Retrospective observational cohort study.

This study took place at 3 university medical centers with mandatory influenza vaccination policies and 4 Veterans Affairs (VA) healthcare systems with nonmandatory influenza vaccination policies.

The study included 2,304 outpatient HCP at mandatory vaccination sites and 1,759 outpatient HCP at nonmandatory vaccination sites.

To determine the incidence and duration of absenteeism in outpatient settings, HCP participating in the Respiratory Protection Effectiveness Clinical Trial at both mandatory and nonmandatory vaccination sites over 3 viral respiratory illness (VRI) seasons (2012–2015) reported their influenza vaccination status and symptomatic days absent from work weekly throughout a 12-week period during the peak VRI season each year. The adjusted effects of vaccination and other modulating factors on absenteeism rates were estimated using multivariable regression models.

The proportion of participants who received influenza vaccination was lower each year at nonmandatory than at mandatory vaccination sites (odds ratio [OR], 0.09; 95% confidence interval [CI], 0.07–0.11). Among HCP who reported at least 1 sick day, vaccinated HCP had lower symptomatic days absent compared to unvaccinated HCP (OR for 2012–2013 and 2013–2014, 0.82; 95% CI, 0.72–0.93; OR for 2014–2015, 0.81; 95% CI, 0.69–0.95).

These data suggest that mandatory HCP influenza vaccination policies increase influenza vaccination rates and that HCP symptomatic absenteeism diminishes as rates of influenza vaccination increase. These findings should be considered in formulating HCP influenza vaccination policies.

Infect Control Hosp Epidemiol 2018;39:452–461

In this study, we sought to evaluate the performance of the Xpert MTB/RIF (Cepheid) assay for the detection of Mycobacterium tuberculosis (MTB) complex DNA on fresh and formalin-fixed, paraffin-embedded (FFPE) tissue specimens from oncology patients in an area with a low prevalence of tuberculosis. We also aimed to retrospectively assess the potential impact of Xpert MTB/RIF on the duration of airborne infection isolation (AII).

A 473-bed, tertiary-care cancer center in New York City.

A total of 203 tissue samples (101 FFPE and 102 fresh) were tested using Xpert MTB/RIF, including 133 pulmonary tissue samples (65.5%) and 70 extrapulmonary tissue samples (34.5%). Acid-fast bacilli (AFB) culture was used as the diagnostic gold standard. The limit of detection (LOD) and reproducibility were also evaluated for both samples types using contrived specimens. The potential impact of the Xpert MTB PCR assay on tissue samples from AII patients on AII duration was retrospectively assessed.

Using the Xpert MTB/RIF for fresh tissue specimens, the sensitivity was 50% (95% CI, 1.3%–98.7%) and the specificity was 99% (95% CI, 94.5%–99.9%). For FFPE tissue specimens, the sensitivity was 100% (95% CI, 63.1%–100%) and the specificity was 98.3% (95% CI, 95.5%–100%. The LOD was 103 colony-forming units (CFU)/mL for both fresh and FFPE tissue specimens, and the Xpert MTB/RIF was 100% reproducible at concentrations 10 times that of the LOD. With an expected turnaround time of 24 hours, the Xpert MTB PCR could decrease the duration of AII from a median of 8 days to a median of 1 day.

The Xpert MTB/RIF assay offers a valid option for ruling out Mycobacterium tuberculosis complex (MTBC) on tissue samples from oncology patients and for minimizing AII resource utilization.

Infect Control Hosp Epidemiol 2018;39:462–466