Reliability of MR Enterography Features for Describing Fibrostenosing Crohn Disease.

Background Clinical decision making and drug development for fibrostenosing Crohn disease is constrained by a lack of imaging definitions, scoring conventions, and validated end points. Purpose To assess the reliability of MR enterography features to describe Crohn disease strictures and determine correlation with stricture severity. Materials and Methods A retrospective study of patients with symptomatic terminal ileal Crohn disease strictures who underwent MR enterography at tertiary care centers (Cleveland Clinic: September 2013 to November 2020; Mayo Clinic: February 2008 to March 2019) was conducted by using convenience sampling. In the development phase, blinded and trained radiologists independently evaluated 26 MR enterography features from baseline and follow-up examinations performed more than 6 months apart, with no bowel resection performed between examinations. Follow-up examinations closest to 12 months after baseline were selected. Reliability was assessed using the intraclass correlation coefficient (ICC). In the validation phase, after five features were redefined, reliability was re-estimated in an independent convenience sample using baseline examinations. Multivariable linear regression analysis identified features with at least moderate interrater reliability (ICC ≥0.41) that were independently associated with stricture severity. Results Ninety-nine (mean age, 40 years ± 14 [SD]; 50 male) patients were included in the development group and 51 (mean age, 45 years ± 16 [SD]; 35 female) patients were included in the validation group. In the development group, nine features had at least moderate interrater reliability. One additional feature demonstrated moderate reliability in the validation group. Stricture length (ICC = 0.85 [95% CI: 0.75, 0.91] and 0.91 [95% CI: 0.75, 0.96] in development and validation phase, respectively) and maximal associated small bowel dilation (ICC = 0.74 [95% CI: 0.63, 0.80] and 0.73 [95% CI: 0.58, 0.87] in development and validation group, respectively) had the highest interrater reliability. Stricture length, maximal stricture wall thickness, and maximal associated small bowel dilation were independently (regression coefficients, 0.09-3.97; P < .001) associated with stricture severity. Conclusion MR enterography definitions and scoring conventions for reliably assessing features of Crohn disease strictures were developed and validated, and feature correlation with stricture severity was determined. © RSNA, 2024 Supplemental material is available for this article. See also the article by Rieder and Ma et al in this issue. See also the editorial by Galgano and Summerlin in this issue.

Do piperacillin/tazobactam and other antibiotics with inhibitory activity against Clostridium difficile reduce the risk for acquisition of C. difficile colonization?

BACKGROUND: Systemic antibiotics vary widely in in vitro activity against Clostridium difficile. Some agents with activity against C. difficile (e.g., piperacillin/tazobactam) inhibit establishment of colonization in mice. We tested the hypothesis that piperacillin/tazobactam and other agents with activity against C. difficile achieve sufficient concentrations in the intestinal tract to inhibit colonization in patients. METHODS: Point-prevalence culture surveys were conducted to compare the frequency of asymptomatic rectal carriage of toxigenic C. difficile among patients receiving piperacillin/tazobactam or other inhibitory antibiotics (e.g. ampicillin, linezolid, carbapenems) versus antibiotics lacking activity against C. difficile (e.g., cephalosporins, ciprofloxacin). For a subset of patients, in vitro inhibition of C. difficile (defined as a reduction in concentration after inoculation of vegetative C. difficile into fresh stool suspensions) was compared among antibiotic treatment groups. RESULTS: Of 250 patients, 32 (13 %) were asymptomatic carriers of C. difficile. In comparison to patients receiving non-inhibitory antibiotics or prior antibiotics within 90 days, patients currently receiving piperacillin/tazobactam were less likely to be asymptomatic carriers (1/36, 3 versus 7/36, 19 and 15/69, 22 %, respectively; P = 0.024) and more likely to have fecal suspensions with in vitro inhibitory activity against C. difficile (20/28, 71 versus 3/11, 27 and 4/26, 15 %; P = 0.03). Patients receiving other inhibitory antibiotics were not less likely to be asymptomatic carriers than those receiving non-inhibitory antibiotics. CONCLUSIONS: Our findings suggest that piperacillin/tazobactam achieves sufficient concentrations in the intestinal tract to inhibit C. difficile colonization during therapy.

Utility of a commercial PCR assay and a clinical prediction rule for detection of toxigenic Clostridium difficile in asymptomatic carriers.

A commercial PCR assay of perirectal swab specimens detected 17 (68%) of 25 asymptomatic carriers of toxigenic Clostridium difficile, including 93% with skin and/or environmental contamination. A clinical prediction rule, followed by PCR screening, could be used to identify carriers at high risk of C. difficile shedding.

Does empirical Clostridium difficile infection (CDI) therapy result in false-negative CDI diagnostic test results?

BACKGROUND: Patients with suspected Clostridium difficile infection (CDI) often receive empirical therapy prior to collection of stool specimens for diagnostic testing. The likelihood that such empirical therapy might result in false-negative CDI test results is unknown. METHODS: We conducted a prospective study of CDI patients to determine the time to conversion of CDI test results, including polymerase chain reaction (PCR) for toxin B genes, glutamate dehydrogenase, and toxigenic culture, from positive to negative during CDI therapy. We evaluated the frequency of and risk factors for persistence of positive CDI tests. For patients receiving empirical therapy, we assessed the frequency of conversion of positive CDI test results at the time of the test order to negative by the time clinical staff collected stool specimens for testing. RESULTS: For 51 CDI patients, PCR, glutamate dehydrogenase, and toxigenic culture results converted to negative at similar rates. For PCR, 14%, 35%, and 45% of positive CDI tests converted to negative after 1, 2, and 3 days of treatment, respectively. Increased age and infection with North American pulsed-field gel electrophoresis strains were associated with persistent positive PCR results. For CDI patients diagnosed at the time of the test order, conversion to negative PCR results by the time clinical stool specimens were collected occurred in 4 of 9 (44%) patients who were prescribed empirical CDI therapy versus 0 of 23 (0%) who were not (P = .004). CONCLUSIONS: Empirical treatment for suspected CDI cases may result in false-negative PCR results if there are delays in stool specimen collection.

Comparison of perirectal versus rectal swabs for detection of asymptomatic carriers of toxigenic Clostridium difficile.

For long-term care and spinal cord injury patients, the sensitivity, specificity, and positive and negative predictive values of perirectal versus rectal cultures for detection of asymptomatic carriers of Clostridium difficile were 95%, 100%, 100%, and 97%, respectively. Perirectal cultures provide an accurate method to detect asymptomatic carriers of C. difficile.

Easily modified factors contribute to delays in diagnosis of Clostridium difficile infection: a cohort study and intervention.

Although rapid laboratory tests are available for diagnosis of Clostridium difficile infection (CDI), delays in completion of CDI testing are common in clinical practice. We conducted a cohort study of 242 inpatients tested for CDI to determine the timing of different steps involved in diagnostic testing and to identify modifiable factors contributing to delays in diagnosis. The average time from test order to test result was 1.8 days (range, 0.2 to 10.6), with time from order to stool collection accounting for most of the delay (mean, 1.0 day; range, 0 to 10). Several modifiable factors contributed to delays, including not providing stool collection supplies to patients in a timely fashion, rejection of specimens due to incorrect labeling or leaking from the container, and holding samples in the laboratory for batch processing. Delays in testing contributed to delays in initiation of treatment for patients diagnosed with CDI and to frequent prescription of empirical CDI therapy for patients with mild to moderate symptoms whose testing was ultimately negative. An intervention that addressed several easily modified factors contributing to delays resulted in a significant decrease in the time required to complete CDI testing. These findings suggest that health care facilities may benefit from a review of their processes for CDI testing to identify and address modifiable factors that contribute to delays in diagnosis and treatment of CDI.

Utility of perirectal swab specimens for diagnosis of Clostridium difficile infection.

For 139 patients tested for Clostridium difficile infection by polymerase chain reaction, the sensitivity, specificity, positive predictive value, and negative predictive value of testing perirectal swabs vs stool specimens were 95.7%, 100%, 100%, and 99.1%, respectively. For selected patients, perirectal swabs provide an accurate toxigenic C. difficile detection strategy.

Transmission of Clostridium difficile from asymptomatically colonized or infected long-term care facility residents.

OBJECTIVE: To test the hypothesis that long-term care facility (LTCF) residents with Clostridium difficile infection (CDI) or asymptomatic carriage of toxigenic strains are an important source of transmission in the LTCF and in the hospital during acute-care admissions. DESIGN: A 6-month cohort study with identification of transmission events was conducted based on tracking of patient movement combined with restriction endonuclease analysis (REA) and whole-genome sequencing (WGS). SETTING: Veterans Affairs hospital and affiliated LTCF.ParticipantsThe study included 29 LTCF residents identified as asymptomatic carriers of toxigenic C. difficile based on every other week perirectal screening and 37 healthcare facility-associated CDI cases (ie, diagnosis >3 days after admission or within 4 weeks of discharge to the community), including 26 hospital-associated and 11 LTCF-associated cases. RESULTS: Of the 37 CDI cases, 7 (18·9%) were linked to LTCF residents with LTCF-associated CDI or asymptomatic carriage, including 3 of 26 hospital-associated CDI cases (11·5%) and 4 of 11 LTCF-associated cases (36·4%). Of the 7 transmissions linked to LTCF residents, 5 (71·4%) were linked to asymptomatic carriers versus 2 (28·6%) to CDI cases, and all involved transmission of epidemic BI/NAP1/027 strains. No incident hospital-associated CDI cases were linked to other hospital-associated CDI cases. CONCLUSIONS: Our findings suggest that LTCF residents with asymptomatic carriage of C. difficile or CDI contribute to transmission both in the LTCF and in the affiliated hospital during acute-care admissions. Greater emphasis on infection control measures and antimicrobial stewardship in LTCFs is needed, and these efforts should focus on LTCF residents during hospital admissions.

A Randomized Trial to Determine the Impact of an Educational Patient Hand-Hygiene Intervention on Contamination of Hospitalized Patient's Hands with Healthcare-Associated Pathogens.

We conducted a non-blinded randomized trial to determine the impact of a patient hand-hygiene intervention on contamination of hospitalized patients' hands with healthcare-associated pathogens. Among patients with negative hand cultures on admission, recovery of pathogens from hands was significantly reduced in those receiving the intervention versus those receiving standard care. Infect Control Hosp Epidemiol 2017;38:595-597.

Utility of a Novel Reflective Marker Visualized by Flash Photography for Assessment of Personnel Contamination During Removal of Personal Protective Equipment.

In an experimental study, the frequency of contamination of healthcare personnel during removal of contaminated personal protective equipment (PPE) was similar for bacteriophage MS2 and a novel reflective marker visualized using flash photography. The reflective marker could be a useful tool to visualize and document personnel contamination during PPE removal. Infect Control Hosp Epidemiol 2016;37:711-713.

Acquisition of Clostridium difficile on Hands of Healthcare Personnel Caring for Patients with Resolved C. difficile Infection.

In an observational study, we found that healthcare personnel frequently acquired Clostridium difficile on their hands when caring for patients with recently resolved C. difficile infection (CDI) (<6 weeks after treatment) who were no longer under contact precautions. Continuing contact precautions after diarrhea resolves may be useful to reduce transmission.

Efficacy of alcohol gel for removal of methicillin-resistant Staphylococcus aureus from hands of colonized patients.

Of 82 patients with methicillin-resistant Staphylococcus aureus (MRSA) colonization, 67 (82%) had positive hand cultures for MRSA. A single application of alcohol gel (2 mL) consistently reduced the burden of MRSA on hands. However, incomplete removal of MRSA was common, particularly in those with a high baseline level of recovery.

Skin and Environmental Contamination in Patients Diagnosed With Clostridium difficile Infection but Not Meeting Clinical Criteria for Testing.

Of 134 patients diagnosed with Clostridium difficile infection, 30 (22%) did not meet clinical criteria for testing because they lacked significant diarrhea or had alternative explanations for diarrhea and no recent antibiotic exposure. For these patients, skin and/or environmental contamination was common only in those with prior antibiotic exposure.

Tigecycline exhibits inhibitory activity against Clostridium difficile in the intestinal tract of hospitalised patients.

No new acquisition of Clostridium difficile occurred among 12 hospitalised patients receiving tigecycline, and pre-existing colonisation was reduced to undetectable levels in 2 patients. Moreover, 91% of stool suspensions obtained during tigecycline therapy exhibited inhibitory activity against C. difficile. These results suggest that tigecycline achieves sufficient concentrations to inhibit intestinal colonisation by C. difficile.

An intervention to reduce health care personnel hand contamination during care of patients with Clostridium difficile infection.

In a quasi-experimental study, an educational intervention to improve the technique for personal protective equipment (PPE) removal in conjunction with disinfection of gloves before removal of PPE reduced acquisition of Clostridium difficile spores on the hands of health care personnel caring for patients with C difficile infection.

Unlocking the Sporicidal Potential of Ethanol: Induced Sporicidal Activity of Ethanol against Clostridium difficile and Bacillus Spores under Altered Physical and Chemical Conditions.

BACKGROUND: Due to their efficacy and convenience, alcohol-based hand sanitizers have been widely adopted as the primary method of hand hygiene in healthcare settings. However, alcohols lack activity against bacterial spores produced by pathogens such as Clostridium difficile and Bacillus anthracis. We hypothesized that sporicidal activity could be induced in alcohols through alteration of physical or chemical conditions that have been shown to degrade or allow penetration of spore coats. PRINCIPAL FINDINGS: Acidification, alkalinization, and heating of ethanol induced rapid sporicidal activity against C. difficile, and to a lesser extent Bacillus thuringiensis and Bacillus subtilis. The sporicidal activity of acidified ethanol was enhanced by increasing ionic strength and mild elevations in temperature. On skin, sporicidal ethanol formulations were as effective as soap and water hand washing in reducing levels of C. difficile spores. CONCLUSIONS: These findings demonstrate that novel ethanol-based sporicidal hand hygiene formulations can be developed through alteration of physical and chemical conditions.

Chlorhexidine Only Works If Applied Correctly: Use of a Simple Colorimetric Assay to Provide Monitoring and Feedback on Effectiveness of Chlorhexidine Application.

We used a colorimetric assay to determine the presence of chlorhexidine on skin, and we identified deficiencies in preoperative bathing and daily bathing in the intensive care unit. Both types of bathing improved with an intervention that included feedback to nursing staff. The assay provides a simple and rapid method of monitoring the performance of chlorhexidine bathing.

Four Moments for Patient Hand Hygiene: A Patient-Centered, Provider-Facilitated Model to Improve Patient Hand Hygiene.

We found that a majority of hospitalized patients were aware of the importance of hand hygiene, but observations indicated that performance of hand hygiene was uncommon. An intervention in which healthcare personnel facilitated hand hygiene at specific moments significantly increased performance of hand hygiene by patients.

Comparison of hand hygiene monitoring using the 5 Moments for Hand Hygiene method versus a wash in-wash out method.

BACKGROUND: One strategy to promote improved hand hygiene is to monitor health care workers' adherence to recommended practices and give feedback. For feasibility of monitoring, many health care facilities assess hand hygiene practices on room entry and exit (wash in-wash out). It is not known if the wash in-wash out method is comparable with a more comprehensive approach, such as the World Health Organization's My 5 Moments for Hand Hygiene method. METHODS: During a 1-month period, a surreptitious observer monitored hand hygiene compliance simultaneously using the wash in-wash out and My 5 Moments for Hand Hygiene methods. RESULTS: For 283 health care worker room entries, the methods resulted in similar rates of hand hygiene compliance (70% vs 72%, respectively). The wash in-wash out method required 148 hand hygiene events not required by the My 5 Moments for Hand Hygiene method (ie, before and after room entry with no patient or environmental contact) while not providing monitoring for 89 hand hygiene opportunities in patient rooms. CONCLUSION: The monitoring methods resulted in similar overall rates of hand hygiene compliance. Use of the wash in-wash out method should include ongoing education and intermittent assessment of hand hygiene before clean procedures and after body fluid exposure in patient rooms.