UNASSIGNED: Including Clostridioides difficile (CD) in gastrointestinal multiplex molecular panels (GIPCR) presents a diagnostic challenge. Incidental detection by polymerase chain reaction (PCR) without consideration of pretest probability (PTP) may inadvertently delay diagnoses of other treatable causes of diarrhea and lead to prescription of unnecessary antibiotics.
UNASSIGNED: We conducted a retrospective study to determine the frequency at which clinicians characterize PTP and disease severity in adult patients who test positive for CD by GIPCR. We organized subjects into cohorts based on the status of their CD PCR, glutamate dehydrogenase enzyme immunoassay (GDH), and toxin A/B detection, as well as by high, moderate, or low CD PTP. We used multivariable regression models to describe predictors of toxin positivity.
UNASSIGNED: We identified 483 patients with positive CD PCR targets. Only 22% were positive for both GDH and CD toxin. Among patients with a low PTP for CDI, 11% demonstrated a positive CD toxin result compared to 63% of patients with a high PTP. A low clinician PTP for CD infection (CDI) correlated with a negative CD toxin result compared to cases of moderate-to-high PTP for CDI (odds ratio, 0.19 [95% confidence interval, .10-.36]). Up to 64% of patients with negative GDH and CD toxin received CD treatment. Only receipt of prior antibiotics, fever, and a moderate-to-high clinician PTP were statistically significant predictors of toxin positivity.
UNASSIGNED: Patients with a positive CD PCR were likely to receive treatment regardless of PTP or CD toxin results. We recommend that CD positivity on GIPCR be interpreted with caution, particularly in the setting of a low PTP.

BACKGROUND: Molecular testing has been used as an adjunct to morphological evaluation in the workup of thyroid nodules. This study investigated the impact of two gene fusions, RET/PTC and THADA/IGF2BP3, that have been described as oncogenic events in thyroid neoplasms.
METHODS: We performed a retrospective, single-centered study at a McGill University teaching hospital in Montreal, Canada, from January 2016 to August 2021. We included patients who underwent surgery for thyroid nodules that pre-operatively underwent molecular testing showing either RET/PTC or THADA/IGF2BP3 gene fusion.
RESULTS: This study included 697 consecutive operated thyroid nodules assessed using molecular testing, of which five had the RET/PTC fusion and seven had the THADA/IGF2BP3 fusion. Of the five nodules in the RET/PTC group, 100% were malignant and presented as Bethesda V/VI. Eighty percent (4/5) were found to have lymph node metastasis. Twenty percent (1/5) had extrathyroidal extensions. Sixty percent (3/5) were a diffuse sclerosing variant of papillary thyroid carcinoma, and the rest were the classical variant. Of the seven THADA/IGF2BP3 nodules, all presented as Bethesda III/IV and 71.4% (5/7) were malignant based on the final pathology analysis, and 28.6% (2/7) were NIFTP. All the THADA/IGF2BP3 fusion malignancies were a follicular variant of papillary thyroid carcinoma. None had lymph node metastasis or displayed extrathyroidal extensions.
CONCLUSIONS: RET/PTC nodules presented as Bethesda V/VI and potentially had more aggressive features, whereas THADA/IGF2BP3 nodules presented as Bethesda III/IV and had more indolent behavior. This understanding may allow clinicians to develop more targeted treatment plans, such as the extent of surgery and adjuvant radioactive iodine treatment.

The standard for diagnosing meningoencephalitis includes cerebrospinal fluid (CSF) culture and viral polymerase chain reaction (PCR). Approval of the FilmArray® BioFire® Meningitis/Encephalitis (ME) panel has reduced time to detection of several pathogens and improved diagnostic sensitivity. The objective of this study was to determine the impact on intravenous (IV) acyclovir duration of the ME panel compared to previously utilized CSF studies within a large health system with a central laboratory. A multicenter quasi-experimental cohort study of adult and pediatric patients was conducted (n = 208). The primary endpoint was duration of IV acyclovir, which was decreased (41.6 v. 30.8 hours; P < 0.01) with the ME panel. Secondary outcomes including test-turnaround time (TAT) and the impact of utilizing a central laboratory were explored. Subgroup analyses demonstrated that number of daily couriers from hospital to the central laboratory (0 versus 7 versus 3 versus 2 couriers) and hospital distance from the central laboratory (0 versus 1-10 versus 11-20 versus 21-30 miles) significantly impacted TAT (P < 0.01). While duration of IV acyclovir for the entire healthcare system was reduced, the duration at individual sites was not impacted by number of couriers or distance from the central laboratory.

Conventional methods for the identification of gastrointestinal pathogens are time-consuming and expensive and have limited sensitivity. The aim of this study was to determine the clinical impact of a comprehensive molecular test, the BioFire FilmArray gastrointestinal (GI) panel, which tests for many of the most common agents of infectious diarrhea in approximately 1 h. Patients with stool cultures submitted were tested on the GI panel (n = 241) and were compared with control patients (n = 594) from the year prior. The most common organisms detected by the GI panel were enteropathogenic Escherichia coli (EPEC, n = 21), norovirus (n = 21), rotavirus (n = 15), sapovirus (n = 9), and Salmonella (n = 8). Patients tested on the GI panel had an average of 0.58 other infectious stool tests compared with 3.02 in the control group (P = 0.0001). The numbers of days on antibiotic(s) per patient were 1.73 in the cases and 2.12 in the controls (P = 0.06). Patients with the GI panel had 0.18 abdomen and/or pelvic imaging studies per patient compared with 0.39 (P = 0.0002) in the controls. The average length of time from stool culture collection to discharge was 3.4 days in the GI panel group versus 3.9 days in the controls (P = 0.04). The overall health care cost could have decreased by $293.61 per patient tested. The GI panel improved patient care by rapidly identifying a broad range of pathogens which may not have otherwise been detected, reducing the need for other diagnostic tests, reducing unnecessary use of antibiotics, and leading to a reduction in hospital length of stay.

We compared an FDA cleared molecular meningitis/encephalitis panel to lab developed viral PCRs and bacterial culture. Of the 67 viral PCR or bacterial culture-positive samples, 92.5% were positive for the same target by the panel. Of the 66 negative samples tested, no targets were detected by the panel, for an agreement of 96.2%.