No abstract

Background:Locoregional recurrence is the major cause of treatment failure after surgery for oral squamous cell carcinoma. Molecular diagnostics have the potential to improve on clinicopathological parameters to predict this recurrence and plan adjuvant treatment. The test most frequently applied is based on detecting TP53 mutations, but alternative methodology is required for cases that harbour the wild-type gene.Methods:One hundred and two cases with tumour-adjacent margins, considered to be clear margins by microscopy, were examined using carefully optimised molecular diagnostics based on detection of the TP53 and Ly-6D markers. The markers were also combined to provide a dual approach.Results:The dual molecular diagnostic identified cases with a significant increase in the probablility of developing locoregional recurrence when tumour-adjacent positive and clear margins were compared (P=0.0001). These tests were most useful when the clearance at the resection margins was 5 mm or less. The TP53-based diagnostic was a better predictor of locoregional recurrence than established clinicopathological parameters.Conclusion:The optimised TP53-based diagnostic rapidly identifies an important subgroup of cases with close margins that will benefit from new treatment modalities to reduce the risk of recurrence.

We implemented universal inpatient Clostridioides difficile screening at an 800-bed hospital. Over 3 years, 2,010 of 47,048 screening tests (4.2%) were positive, with significantly higher rates of C. difficile colonization on transplant units than medical-surgical units: 5.4% (152 of 2,801) versus 4.3% (880 of 20,564), respectively (P = .005). Compliance with screening ranged from 79% to 96%.

Objective: To determine risk factors for Clostridioides difficile colonization and C. difficile infection (CDI) among patients admitted to the intensive care unit (ICU). Design: Retrospective observational cohort study. Setting: Tertiary-care facility. Patients: All adult patients admitted to an ICU from July 1, 2015, to November 6, 2019, who were tested for C. difficile colonization. Patients with CDI were excluded. Methods: Information was collected on patient demographics, comorbidities, laboratory results, and prescriptions. We defined C. difficile colonization as a positive nucleic acid amplification test for C. difficile up to 48 hours before or 24 hours after intensive care unit (ICU) admission without evidence of active infection. We defined active infection as the receipt of an antibiotic whose only indication is the treatment of CDI. The primary outcome measure was the development of CDI up to 30 days after ICU admission. Logistic regression was used to model associations between clinical variables and the development of CDI. Results: The overall C. difficile colonization rate was 4% and the overall CDI rate was 2%. Risk factors for the development of CDI included C. difficile colonization (aOR, 13.3; 95% CI, 8.3–21.3; P < .0001), increased ICU length of stay (aOR, 1.04; 95% CI, 1.03–1.05; P < .0001), and a history of inflammatory bowel disease (aOR, 3.8; 95% CI, 1.3–11.1; P = .02). Receipt of any antibiotic during the ICU stay was associated with a borderline increased odds of CDI (aOR, 1.9; 95% CI, 1.0–3.4; P = .05). Conclusion: C. difficile colonization is associated with the development of CDI among ICU patients.

BackgroundDiagnostic stewardship is an emerging tool that can be used to prevent overuse of diagnostics. Because GI mPCR (GI multiplex PCR panel) tests can be ordered on formed stool, the test has lower pre-test probability for Clostridium difficile (C. difficile) infection than traditional singleplex PCR. Furthermore, after 48hours of admission, most other targets on the GI mPCR are no longer clinically relevant. Any C. difficile testing on inappropriate specimens may increase the rate of Lab ID events (positive C. difficile tests after 3 days of admission) without improving detection of true infections.MethodsIn January 2018, our 700-bed academic medical center implemented an informatics-based intervention that restricted ordering of the GI mPCR to the first 48 hours of hospitalization. After 48 hours, providers were required to contact microbiology to request an exception (see Figure 1). Singleplex PCR testing for C. difficile was available throughout admission. Orders for the GI mPCR test require the provider to note whether the patient had >3 loose stools in the previous day. Statistical analysis performed with STATA software.ResultsA total of 282 late (after 48 hours of admission) GI mPCR tests were ordered in the 104 days before restriction and 210 late tests were ordered in the 104 days after. Late GI mPCR tests (before and after restriction) resulted in diagnoses other than C. difficile less than 5% of the time (20 of 492 tests). 11.7% (24 of 210) of late GI mPCR tests were ordered for patients who did not have >3 loose stools in the previous day. Prior to restriction, 15% (41 of 282) of Lab ID events from GI mPCR were for patients who had already tested positive for C. difficile earlier in the same admission. Following the intervention, there was a decreased proportion of GI mPCR tests that were positive for C. difficile (from 14.5% to 11.3%, P = 0.26), as well as a significantly decreased rate of Lab ID events detected by GI mPCR, from 7.2/10,000 patient days to 4.0/10,000 patient days (P = 0.01).ConclusionAccurate diagnosis of C. difficile infection is important for treatment and prevention efforts, yet these data show that many rapid GI mPCR tests are inappropriately ordered on patients who may not have loose stools and who are unlikely to have an alternate diagnosis. EMR-based restriction on the GI mPCR ordering time reduced Lab ID events of C. difficile infection without missing important alternate diagnoses.Figure 1.Disclosures All authors: No reported disclosures.

BackgroundInfluenza vaccination of healthcare workers is an important component of keeping patients safe, but must be paired with exclusion of ill healthcare workers (HCW) from work. CDC recommends exclusion from work until afebrile for 24 hours, but not all HCW with influenza develop fever and may still be a risk for spreading. Half of HCW with influenza in an H1N1-dominant season (2013–2014) at our institution were afebrile.MethodsFrom 1/31–4/24/18 (H3N2-dominant season), HCW with fever or cough were screened for influenza and respiratory syncytial virus by polymerase chain reaction of flocked nasopharyngeal swabs. Additional HCW were tested by their primary care providers. We collected influenza vaccination status and symptoms and calculated the proportion of influenza-positive HCWs with fever or cough. Infection control practitioners (ICPs) contacted each influenza-positive HCW to identify potential patient or HCW exposures 24 hours prior to symptom onset and offered oseltamivir prophylaxis to exposed patients and HCW.ResultsOf 186 HCW tested by UCM, 49 (26%) tested positive for influenza (35 with influenza A; 14 with influenza B) and 11 (6%) tested positive for RSV. Forty-eight HCW (98%) received influenza vaccination. Fever was reported in only 19 (54%) HCW with influenza A and three (21%) HCW with influenza B. Cough was present in the majority of HCW (34 (97%) with influenza A and 12 (86%) with influenza B). An additional 55 HCW were diagnosed with influenza by their primary care providers. ICPs performed contact investigations for 43 HCW who reported exposure to patients or other HCW between 24 hours before symptom onset through the time of diagnosis. Occupational medicine provided 138 courses of prophylactic oseltamivir to HCW.ConclusionAfebrile influenza illness is common; current workforce guidelines are insufficient to prevent exposure in the healthcare setting. Expanding employee influenza screening to include fever OR cough doubled the number influenza positive HCW identified. Despite excellent influenza vaccination rates, vigilance is critical to prevent influenza transmission in the hospital. HCW screening for influenza based on fever OR cough, exclusion from work, and identification of potential exposures can help keep patients and colleagues safe.Disclosures All authors: No reported disclosures.

Background: Unnecessary testing for Clostridioides difficile can lead facilities to overreport laboratory-identified (LabID) events. Because false-positive LabID tests could dilute infection control resources, we developed best practice alerts (BPAs) in the electronic health record, educational materials as well as a follow-up system to help reduce unnecessary testing and, therefore, reduce false-positive results. Methods: Three BPAs were initiated in late August, 2018. Alerts fired when clinicians tried to order repeat C. difficile testing after a positive result, testing within 24 hours of laxative administration and to order a multiplex PCR panel for GI pathogens >48 hours after admission. The GI multiplex PCR test consists of 21 targets, including C. difficile, but it allows for testing solid stool. All alerts gave suggestions for how to proceed (ie, not test for cure from previous positive, wait until laxatives wear off, or call for approval before GI panel) but could be bypassed by clinicians. Educational emails and signage were distributed to all house staff and clinicians in all clinical areas at the start of the program. For each bypassed BPA, infection control physicians contacted the ordering clinician by email or phone to explain why testing was not advised. Results: Between September 5, 2018, and April 23, 2019, 1,217 BPAs were issued: 634 in first half and 583 in the second half. Of these, 268 (22%) were bypassed by clinicians (Fig. 1). There was no significant decrease in bypassing BPAs. In the first half of the intervention, 22% of BPAs were bypassed (141 of 634). In the second 4 months, 22% of BPAS were still bypassed (127 of 583; P = .85). Of the 40 ordering services, 8 had no bypassed BPAs in the first half and 9 had no bypassed BPAs in the second half. Conclusions: Educating providers and following up after bypassed BPAs did not decrease the number of bypassed BPAs. Although fewer BPAs were issued in the second half of the intervention, more analysis is needed to understand whether this decrease is significant. In this study, 268 unnecessary C. difficile tests were ordered over 8 months.Funding: NoneDisclosures: None

BackgroundThe National Health Safety Network (NHSN) requires reporting of Lab ID events for C. difficile infection (CDI) including all positive clinical tests after day three of hospitalization. Nucleic acid amplification tests (NAAT) that detect genes for toxins A and/or B may be overly sensitive, in some cases detecting C. difficile colonization. Some have advocated for two-stage testing, with positive NAAT tests followed by confirmatory enzyme immunoassay (EIA) to detect the presence of toxin and minimize the downside of false positives (i.e. additional NHSN reports or overuse of antibiotics). We aimed to better understand clinical characteristics of patients with positive NAAT and/or EIA tests.MethodsOur hospital uses Xpert C. difficile assay (Cepheid), a NAAT method utilizing polymerase chain reaction (PCR), to diagnose CDI on unformed stool only. As part of a 6 month quality initiative, we pilot tested the C.DIFF QUIK CHEK COMPLETE® test (Alere), an EIA that tests for C. difficileantigen (Ag) and toxin, on all specimens that tested positive by NAAT. We abstracted clinical data from the medical record for a subset of patients who underwent EIA testing.ResultsOver 6 months, 294 patients had a positive test by NAAT. Of these, 258 (87.8%) underwent EIA testing. 67 (26.0%) were Ag+/toxin+, 173 (67.1%) were Ag+/toxin-, and 18 (6.8%) were Ag-/toxin-. Mortality rates were as follows: Ag+/toxin+, 17.9% (12/67); Ag+/toxin-, 13.9% (24/173); Ag-/toxin-, 27.8% (5/18), P = 0.27. Among the EIA toxin negative patients who underwent chart review, 81% had 3 or more loose stools within 24 hours, 62% had abdominal pain, nausea, or vomiting, and 27% had a WBC > 15.ConclusionThe majority of patients testing positive for CDI by NAAT had a negative EIA test for toxin. There was no significant difference in mortality between EIA toxin positive and negative. Those with negative EIA toxin tests often had clinically significant symptoms of CDI. A two-stage CDI testing algorithm with NAAT followed by EIA for toxin may exclude patients with clinically significant CDI but would have resulted in a 75% reduction in reported NHSN LabID events.Disclosures All authors: No reported disclosures.