Faculty Bibliography

BACKGROUND:Gastrointestinal infection is a major cause of morbidity. We sought to characterize the pathogenic etiologies of gastrointestinal infection to identify seasonal patterns and predictors of specific infections utilizing a multiplex PCR assay in clinical practice. METHODS:We performed a cross-sectional study of 9403 patients who underwent 13,231 stool tests with a FilmArray gastrointestinal pathogen PCR panel during an episode of diarrhea from March 2015 to May 2017. Our primary outcome was the presence of a positive panel. Logistic regression was used to test for associations between season and infections. RESULTS:A positive result was found in 3426 tests (25.9%) in 2988 patients (31.8%), yielding 4667 pathogens consisting of 1469 viruses (31.5%), 2925 bacteria (62.7%), and 273 parasites (5.8%). Age less than 50 years was associated with a higher prevalence of pathogens compared to age ≥ 50 (p < 0.0001). The overall prevalence of a positive result for bacteria peaked in the summer (635, 29.2%), and the prevalence of viruses peaked in the winter (446, 31.8%). Compared to the winter, testing in the summer yielded a higher prevalence of bacteria (OR 1.52, 95% CI 1.33, 1.73, p < 0.0001) and lower odds of viruses (OR 0.69, 95% CI 0.58, 0.81, p < 0.0001), primarily driven by E. coli species and norovirus. CONCLUSIONS:Season was a major determinant in detecting specific pathogens. Our substantially lower positivity rate than previous reports in the literature on multiplex PCR assays may more accurately reflect true clinical practice. Recognizing the temporal distribution of enteric pathogens may help facilitate empiric treatment decisions in certain clinical situations.

BACKGROUND:Gastrointestinal bleeding (GIB) is a frequent cause of re-admission in patients with continuous-flow left ventricular assist devices (CF-LVADs) and is associated with multiple endoscopic procedures and high resource utilization. Our aim was to determine the diagnostic and therapeutic yield of endoscopy and to develop a more cost-effective approach for the management of GIB in CF-LVAD recipients. METHODS:We retrospectively reviewed 428 patients implanted with a CF-LVAD between 2009 and 2016 at the Columbia University Medical Center and identified those hospitalized for GIB. Patients were categorized into upper GIB (UGIB), lower GIB (LGIB) and occult GIB (OGIB), based on clinical presentation. RESULTS:Eighty-seven CF-LVAD patients underwent a total of 164 GIBs, resulting in 239 endoscopies. Index presentation was consistent with UGIB in 30 (34.5%), LGIB in 19 (21.8%) and OGIB in 38 (43.7%) patients. On the first GIB, 147 endoscopies localized a bleeding source in 49 (30%), resulting in 24 (16.3%) endoscopic interventions. Of 45 lesions identified, arteriovenous malformations (AVMs) were the most common (22, 48.9%). A gastric or small bowel source (HR 2.8, p = 0.003) and an endoscopic intervention (HR 1.9, p = 0.04) predicted recurrent GIB. The proposed algorithm may reduce the number of endoscopic procedures by 45% and costs by 35%. CONCLUSIONS:Occult GIB is the most common presentation in CF-LVAD patients and carries the lowest diagnostic and therapeutic yield of endoscopy. Performing an intervention was among the strongest predictors of recurrent GIB. Our proposed algorithm may decrease the number of low-yield procedures and improve resource utilization.

BACKGROUND:Case series suggest a possible association between bariatric surgery and incident IBD. AIM/OBJECTIVE:The aim of this study was to evaluate the association between bariatric surgery and new-onset IBD. METHODS:We first conducted a multi-institutional case series of patients with a history of IBD and bariatric surgery. We next conducted a matched case-control study using medical and pharmacy claims from 2008 to 2012 in a US national database from Source Healthcare Analytics LLC. Bariatric surgery was defined by ICD-9 or CPT code. Bariatric surgery was evaluated as recent (code in database timeframe), past (past history V code) or no history. Conditional logistic regression was used to estimate odds ratios (OR) and 95% CI for new-onset IBD, CD and UC. RESULTS:A total of 15 cases of IBD (10 CD, 4 UC, 1 IBD, type unclassified) with a prior history of bariatric surgery were identified. Most cases were women, had Roux-en-Y surgery years prior to diagnosis and few IBD-related complications. A total of 8980 cases and 43 059 controls were included in our database analysis. Adjusting for confounders, a past history of bariatric surgery was associated with an increased risk of new-onset IBD (OR 1.93, 95% CI 1.34-2.79). However, patients who had recent bariatric surgery did not appear to be at shorter term risk of IBD (OR 0.94, 95% CI 0.58-1.52). CONCLUSION/CONCLUSIONS:New-onset IBD was significantly associated with a past history of bariatric surgery. This potential association needs to be confirmed in future prospective studies.

BACKGROUND:Patients with celiac disease and inflammatory bowel disease, two immune-mediated luminal conditions, have higher rates of certain infections than healthy counterparts. The prevalence of many gastrointestinal infections in these patients, however, is unknown. AIMS/OBJECTIVE:Using a novel clinical stool pathogen PCR test, we investigated the hypothesis that patients with celiac disease/inflammatory bowel disease had different distributions of diarrheal pathogens than other patients. METHODS:We performed a retrospective cohort study of outpatients who underwent stool pathogen testing with the FilmArray Gastrointestinal PCR Panel (BioFire Diagnostics, Salt Lake City, UT) at our institution from January 1 to December 31, 2015. Rates of pathogens were measured in patients with or without celiac disease/inflammatory bowel disease. RESULTS:Of 955 patients, 337 had positive test for any pathogen, with 465 bacterial, parasitic, or viral pathogens identified. One hundred and twenty-seven patients (13.3%) had celiac disease or inflammatory bowel disease, of which 29/127 (22.8%) had a positive test, compared to 308/828 other patients (37.2%) (p = 0.002). Patients with celiac disease/inflammatory bowel disease had significantly fewer viruses (1.6 vs. 8.1% of patients; p = 0.008) and parasites (0 vs. 3.3%; p = 0.039), with nonsignificant trend toward fewer bacteria (21.3 vs. 29.2%; p = 0.063). Escherichia coli species were most common in both populations. CONCLUSIONS:Stool PCR identified numerous pathogens in patients with or without celiac disease/inflammatory bowel disease. Patients with celiac disease/inflammatory bowel disease were significantly less likely to have any pathogen identified, and had significantly fewer viruses and parasites. In this population, knowledge of common pathogens can guide diagnostic evaluation and offer opportunities for treatment.