Polymerase chain reaction (PCR) assays based on the detection of the toxin B gene are replacing enzyme-linked immunosorbent assay (ELISA)–based toxin production detection or cell cytotoxicity assay in most laboratories.

To determine the proportion of pediatric patients diagnosed withClostridium difficile infection by PCR who would have also been diagnosed by ELISA and to compare the clinical characteristics of PCR+/ELISA+ vs PCR+/ELISA− patients.

Using the microbiology laboratory information system, stool samples positive for C. difficile by PCR between October 2010 and July 2014 were identified. Using frozen stool specimens, an ELISA for toxin A and B was performed. A retrospective medical chart review was conducted to obtain demographic and clinical data. Duplicate samples were excluded.

A total of 136 PCR-positive samples underwent ELISA testing: 54 (40%) were positive for toxin A or B. The mean (SD) age of the entire cohort was 8.5 (6.2) years. There was no difference in age, gender, clinical manifestation, previous medical problems, and management between patients positive or negative by ELISA. However, patients positive by ELISA were more likely to have had a recent exposure to antibiotics (67.9% vs 50%; crude odds ratio, 2.1 [95% CI, 1.03–4.28]).

In our pediatric population, 60% of patients with C. difficile diagnosed by PCR had no toxin detectable by ELISA. ELISA-negative patients were less likely to have received an antibiotic recently compared with ELISA-positive patients. These results highlight the need to standardize laboratory criteria for the diagnosis of C. difficile infections in children.

Infect Control Hosp Epidemiol 2016;37:1087–1093

Asynchronous virtual patient care is increasingly used; however, the effectiveness of virtually delivering guideline-concordant care in conjunction with antibiotic stewardship initiatives remains uncertain. We developed a bundled stewardship intervention to improve antibiotic use in E-visits for upper respiratory tract infections (URTIs).

In this before-and-after study, adult patients who completed E-visits for “cough,” “flu,” or “sinus symptoms” at Michigan Medicine between January 1, 2018, and September 30, 2020, were included. Patient demographics, diagnoses, and antibiotic details were collected. The multifaceted intervention occurred over 6 months. Segmented linear regression was performed to estimate the effect of the intervention on appropriate antibiotic use for URTI diagnoses (defined as no antibiotic prescribed) and sinusitis (defined as guideline-concordant antibiotic selection and duration). Regression lines were fit to data before the bundled intervention (January 2019) and after the bundled intervention (May 2019).

In total, 5,151 E-visits were included. The intervention decreased the number of visits for flu, cough, or sinus symptoms prescribed antibiotics from 43.2% to 28.9% (P < .001). Guideline concordance of antibiotic prescriptions improved following the intervention: first-line amoxicillin-clavulanate rose from 37.9% of prescriptions to 66.1% of prescriptions (P < .001), second-line doxycycline rose from 13.8% to 22.7% (P < .001); and median duration of antibiotics decreased from 10 days to 5 days (P < .001).

A multifaceted stewardship bundle for E-visits involving both changes in the EMR and audit and feedback improved guideline-concordant antibiotic use for URTIs. This approach can aid stewardship efforts in the ambulatory care setting with regard to telemedicine.

To evaluate the pattern of blood-culture utilization among a cohort of 6 hospitals to identify potential opportunities for diagnostic stewardship.

We completed a retrospective analysis of blood-culture utilization during adult inpatient or emergency department (ED) encounters in 6 hospitals from May 2019 to April 2020. We investigated 2 measures of blood-culture utilization rates (BCURs): the total number of blood cultures, defined as a unique accession number per 1,000 patient days (BCX) and a new metric of blood-culture events per 1,000 patient days to account for paired culture practices. We defined a blood-culture event as an initial blood culture and all subsequent samples for culture drawn within 12 hours for patients with an inpatient or ED encounter. Cultures were evaluated by unit type, positivity and contamination rates, and other markers evaluating the quality of blood-culture collection.

In total, 111,520 blood cultures, 52,550 blood culture events, 165,456 inpatient admissions, and 568,928 patient days were analyzed. Overall, the mean BCUR was 196 blood cultures per 1,000 patient days, with 92 blood culture events per 1,000 patient days (range, 64–155 among hospitals). Furthermore, 7% of blood-culture events were single culture events, 55% began in the ED, and 77% occurred in the first 3 hospital days. Among all blood cultures, 7.7% grew a likely pathogen, 2.1% were contaminated, and 5.9% of first blood cultures were collected after the initiation of antibiotics.

Blood-culture utilization varied by hospital and was heavily influenced by ED culture volumes. Hospital comparisons of blood-culture metrics can assist in identifying opportunities to optimize blood-culture collection practices.

Methicillin-resistant Staphylococcus aureus (MRSA) nasal swabs are utilized to guide the discontinuation of empiric MRSA therapy. In multiple studies, MRSA nasal swabs have been shown to have a negative predictive value (NPV) of ~99% in non-oncology patients with pneumonia and other infections. We evaluated the performance characteristics of a negative MRSA nasal swab in the acute myeloid leukemia (AML) populaion to determine its NPV.

Retrospective chart review.

This study included adult AML patients with a suspected infection and a MRSA nasal swab collected between 2013 and 2018.

MRSA nasal swab and culture-documented infections were identified to determine the sensitivity, specificity, NPV, and positive predictive value of the MRSA nasal swabs.

In total, 194 patients were identified, and 484 discrete encounters were analyzed. Overall, 468 (97%) encounters had a negative MRSA nasal swab upon admission with no cultured documented MRSA infection during their hospitalization. However, 3 encounters (0.6%) had a negative MRSA nasal swab with a subsequent cultured documented MRSA infection during their admission. Identified infections were bacteremia (n = 2) and confirmed pneumonia (n = 1). MRSA nasal swab had a sensitivity of 62% (95% CI, 0.24–0.91), specificity of 98% (95% CI, 0.96–0.99), positive predictive value of 38% (95% CI, 0.21–0.6), and NPV of 99% (95% CI, 0.98–1).

A negative MRSA nasal swab has a 99% NPV for subsequent MRSA infections in AML patients with no prior history of MRSA colonization or infection. Based on these findings, a negative MRSA nasal swab can help guide de-escalation of empiric MRSA antibiotic therapy.

We quantitatively assessed the fit failure rate of N95 respirators according to the number of donning/doffing and hours worn.

Experimental study.

A tertiary-care referral center in South Korea.

In total, 10 infection control practitioners participated in the fit test.

The first experiment comprised 4 consecutive 1-hour donnings and fit tests between each donning. The second experiment comprised 2 consecutive 3-hour donnings and fit tests between each donning. The final experiment comprised fit tests after an 1-hour donning or a 2-hour donning.

For 1-hour donnings, 60%, 70%, and 90% of the participants had fit failures after 2, 3, and 4 consecutive donnings, respectively. For 3-hour donnings, 50% had fit failure after the first donning and 70% had failures after 2 consecutive donnings. All participants passed the fit test after refitting whenever fit failure occurred. The final experiment showed that 50% had fit failure after a single use of 1 hour, and 30% had fit failure after a single use of 2 hours.

High fit-failure rates were recorded after repeated donning and extended use of N95 respirators. Caution is needed for reuse (≥1 time) and extended use (≥1 hour) of N95 respirators in high-risk settings such as those involving aerosol-generating procedures. Although adequate refitting may recover the fit factor, the use of clean gloves and strict hand hygiene afterward should be ensured when touching the outer surfaces of N95 respirators for refitting.

The ways that device-associated infection prevention practices changed during the coronavirus disease 2019 (COVID-19) pandemic remain unknown. We collected data mid-pandemic to assess the use of several infection prevention practices and for comparison with historical data.

Repeated cross-sectional survey.

US acute-care hospitals.

Infection preventionists.

We surveyed infection preventionists from a national random sample of 881 US acute-care hospitals in 2021 to estimate the current use of practices to prevent catheter-associated urinary tract infection (CAUTI), central line–associated bloodstream infection (CLABSI), and ventilator-associated events (VAE). We compared the 2021 results with those from surveys occurring every 4 years since 2005.

The 2021 survey response rate was 47%; previous survey response rates ranged from 59% to 72%. Regular use of most practices to prevent CLABSI (chlorhexidine gluconate for site antisepsis, 99.0%, and maximum sterile barrier precautions, 98.7%) and VAE (semirecumbent positioning, 93.4%, and sedation vacation, 85.8%) continued to increase or plateaued in 2021. Conversely, use of several CAUTI prevention practices (portable bladder ultrasound scanner, 65.6%; catheter reminders or nurse-initiated discontinuation, 66.3%; and intermittent catheterization, 37.3%) was lower in 2021, with a significant decrease for some practices compared to 2017 (P ≤ .02 for all comparisons). In 2021, 42.1% of hospitals reported regular use of the newer external urinary collection devices for women.

Although regular use of CLABSI and VAE preventive practices continued to increase (or plateaued), use of several CAUTI preventive practices decreased during the COVID-19 pandemic. Structural issues relating to care during the pandemic may have contributed to a decrease in device-associated infection prevention practices.

Little is known about the short-term dynamics of methicillin-resistant Staphylococcus aureus (MRSA) transmission between patients and their immediate environment. We conducted a real-life microbiological evaluation of environmental MRSA contamination in hospital rooms in relation to recent patient activity.

Observational pilot study.

Two hospitals, hospital 1 in Zurich, Switzerland, and hospital 2 in Ann Arbor, Michigan, United States.

Inpatients with MRSA colonization or infection.

At baseline, the groin, axilla, nares, dominant hands of 10 patients and 6 environmental high-touch surfaces in their rooms were sampled. Cultures were then taken of the patient hand and high-touch surfaces 3 more times at 90-minute intervals. After each swabbing, patients’ hands and surfaces were disinfected. Patient activity was assessed by interviews at hospital 1 and analysis of video footage at hospital 2. A contamination pressure score was created by multiplying the number of colonized body sites with the activity level of the patient.

In total, 10 patients colonized and/or infected with MRSA were enrolled; 40 hand samples and 240 environmental samples were collected. At baseline, 30% of hands and 20% of high-touch surfaces yielded MRSA. At follow-up intervals, 8 (27%) of 30 patient hands, and 10 (6%) of 180 of environmental sites were positive. Activity of the patient explained 7 of 10 environmental contaminations. Patients with higher contamination pressure score showed a trend toward higher environmental contamination.

Environmental MRSA contamination in patient rooms was highly dynamic and was likely driven by the patient’s MRSA body colonization pattern and the patient activity.

To conduct a process evaluation of a respiratory culture diagnostic stewardship intervention.

Mixed-methods study.

Tertiary-care pediatric intensive care unit (PICU).

Critical care, infectious diseases, and pulmonary attending physicians and fellows; PICU nurse practitioners and hospitalist physicians; pediatric residents; and PICU nurses and respiratory therapists.

This mixed-methods study was conducted concurrently with a diagnostic stewardship intervention to reduce the inappropriate collection of respiratory cultures in mechanically ventilated children. We quantified baseline respiratory culture utilization and indications for ordering using quantitative methods. Semistructured interviews informed by these data and the Consolidated Framework for Implementation Research (CFIR) were then performed, recorded, transcribed, and coded to identify salient themes. Finally, themes identified in these interviews were used to create a cross-sectional survey.

The number of cultures collected per day of service varied between attending physicians (range, 2.2–27 cultures per 100 days). In total, 14 interviews were performed, and 87 clinicians completed the survey (response rate, 47%) and 77 nurses or respiratory therapists completed the survey (response rate, 17%). Clinicians varied in their stated practices regarding culture ordering, and these differences both clustered by specialty and were associated with perceived utility of the respiratory culture. Furthermore, group “default” practices, fear, and hierarchy were drivers of culture orders. Barriers to standardization included fear of a missed diagnosis and tension between practice standardization and individual decision making.

We identified significant variation in utilization and perceptions of respiratory cultures as well as several key barriers to implementation of this diagnostic test stewardship intervention.

To assess the status of antibiotic prescribing in the ambulatory setting for adult patients with acute respiratory infections (ARIs) and to identify opportunities and barriers for outpatient antibiotic stewardship programs (ASPs).

Mixed methods including point prevalence using chart reviews, surveys, and collaborative learning.

Hospital-owned clinics in the New York City area.

In total, 31 hospital-owned clinics from 9 hospitals and health systems participated in the study to assess ARI prescribing practices for patients >18 years old.

Each clinic performed a survey of current stewardship practices, retrospective chart reviews of prescribing in 30 randomly selected ARI patients from October 2015 to March 2016, and surveys of provider characteristics and knowledge. Clinics participated in collaborative learning with peers and experts in antibiotic stewardship and collected data from June 2016 to August 2016. Sites received data reports by individual clinic, aggregated by hospital, and were compared among participating clinics.

Few sites had outpatient stewardship activities. The retrospective review of 1,004 ARI patients revealed that 37.3% of ARI patients received antibiotics, with significant variation in prescribing practices among sites (17.4%–71.0%; P<.001). Macrolides were the most commonly prescribed antibiotics. Most of the 302 respondents recognized the need for tools to assist in prescribing.

This collaborative study establishes a baseline assessment of the status of outpatient ASPs in New York City. It provides hospitals, health systems, and individual clinics with specific data to inform their development of stewardship interventions targeting ARIs.