Stool Pathogens Research Articles

S878 Fecal Calprotectin Level Is Nonlinearly Associated With GI Pathogen Detection by PCR in Patients With and Without Inflammatory Bowel Disease

Introduction: Fecal calprotectin (FCP) is an inflammatory marker frequently used to monitor inflammatory bowel disease (IBD) activity, but it can also be elevated in gastrointestinal infections. The impact of infections on FCP level in people with IBD has not been well described across pathogens. The objective of our study was to quantify the relationship between FCP levels and lab-confirmed infections in people with and without IBD. Methods: We performed a retrospective cohort study at a tertiary-care referral center of inpatient and outpatient encounters during which FCR and gastrointestinal pathogen polymerase-chain reaction (GI PCR) testing were conducted. Using non-parametric tests and quantile regression, we compared FCP levels between individuals with and without IBD and with and without pathogen detection. Results: There were 3,399 encounters with FCP and GI PCR testing from 2,780 unique individuals between August 1, 2016 and February 17, 2022. Overall, 1819 (53.5%) encounters were individuals with IBD (n=1,819, Table). Pathogens were detected in 757 encounters (22.3%). There was no significant difference in pathogen detection or pathogen type between groups with and without IBD (p >0.9). The median FCP was 46 mg/kg in individuals without IBD and 265 mg/kg in those with IBD (p< 0.001). Among individuals without IBD, the median FCP was significantly elevated when a pathogen was detected (64 vs. 41 mg/kg, p=0.0003, Figure), but FCP was not significantly elevated among those with IBD when a pathogen was detected (299 vs. 255 mg/kg, p=0.207). After adjusting for age and IBD status in quantile regression, pathogen detection was only significantly associated with higher FCP in the lower two quartiles, though IBD remained significantly associated with higher FCP at all levels (p >0.001). After adjusting for IBD and age, FCP was significantly associated with detection of bacterial pathogens and multiple pathogens in the lower two quartiles. Conclusion: Pathogen detection by GI PCR is associated with elevated FCP, though this relationship is nonlinear and varies by IBD status. Even after stratifying by IBD status, there is significant variability in FCP, suggesting that factors in addition to infection may be playing a role, including potentially measurement error, or a greater immune reaction to pathogen infection in IBD leading to mild flares. Our findings indicate that FCP may be an adjunct to, but not a substitute for stool pathogen testing.Figure 1.: Fecal calprotectin levels by stool pathogen testing result and inflammatory bowel disease (IBD) diagnosis Table 1. - Characteristics of patients with and without IBD who had fecal calprotectin and gastrointestinal pathogen testing Variable OverallN = 3,347 1 IBD diagnosis p-value 2 No IBDN = 1,528 1 IBDN = 1,819 1 Fecal calprotectin (mg/kg) 107 (31, 498) 46 (24, 168) 265 (56, 903) < 0.001 Pathogen detected 744 (22%) 340 (22%) 404 (22%) >0.99 Age (years) 39 (25, 57) 41 (23, 61) 38 (26, 55) 0.02 Sex < 0.001 Female 2,013 (60%) 988 (65%) 1,025 (56%) Male 1,333 (40%) 540 (35%) 793 (44%) Race 0.13 African American 332 (9.9%) 135 (8.8%) 197 (11%) American Indian or Alaska Native 5 (0.1%) 3 (0.2%) 2 (0.1%) Asian 92 (2.8%) 51 (3.3%) 41 (2.3%) Caucasian 2,768 (83%) 1,277 (84%) 1,491 (82%) Native Hawaiian and Other Pacific Islander 1 (< 0.1%) 1 (< 0.1%) 0 (0%) Other 113 (3.4%) 49 (3.2%) 64 (3.5%) Patient Refused 18 (0.5%) 5 (0.3%) 13 (0.7%) Unknown 16 (0.5%) 7 (0.5%) 9 (0.5%) Ethnicity 0.35 Hispanic or Latino 89 (2.7%) 49 (3.2%) 40 (2.2%) Non-Hispanic or Latino 3,193 (96%) 1,449 (95%) 1,744 (96%) Patient Refused 22 (0.7%) 10 (0.7%) 12 (0.7%) Unknown 39 (1.2%) 18 (1.2%) 21 (1.2%) Inpatient encounter 1,435 (43%) 523 (34%) 912 (50%) < 0.001 1 Median (IQR); n (%) ; 2 Wilcoxon rank sum test; Pearson's Chi-squared test; Fisher's exact test.

S2704 A New Protein Losing Enteropathy: Autoimmune Cryptolytic Enterocolitis

Introduction: Protein losing enteropathy (PLE) can be classified into erosive, non-erosive, and increased interstitial pressure PLE. Presenting signs are often chronic non-bloody diarrhea, anasarca, abdominal pain, and weight loss. We present a complex case of a PLE presentation with a novel diagnosis. Case Description/Methods: A 30-year-old woman with a history of migraines presented with severe abdominal pain and chronic diarrhea. She was on long-term combined estrogen-progestin oral contraceptive pills (OCP) and chronic high dose non-steroidal anti-inflammatory (NSAID) medications. She was exposed to mycoplasma pneumoniae one month prior to presentation, without other infectious exposures. Laboratory tests were notable for hemoglobin 6 g/dL, albumin 0.5 g/dL, stool pathogen PCR negative, and fecal calprotectin >3000µg/g. Extensive infectious work up only revealed Mycoplasma IgM+. Inflammatory markers and alpha-1 anti-trypsin clearance were elevated, and she was found to have warm autoimmune hemolytic anemia. CT angiography excluded ischemia and vasculitis (autoimmune serologies were negative), revealing diffuse enterocolitis, confirmed on magnetic resonance enterography with ileal ulcers. Endoscopic evaluation revealed diffuse superficial ulcerations terminal ileum and colon with diffuse mucosal sloughing. Histopathology revealed diffusely injured crypts with crypt drop-out and minimal inflammation, without any findings to suggest infection, inflammatory bowel disease (IBD) or autoimmune enteritis (Figure). Normal B-cell switching studies excluded common variable immunodeficiency (CVID). Due to profound anasarca and inability to tolerate oral intake, albumin infusions and total parenteral nutrition were started. There was minimal response to systemic or topical steroids. Diarrhea was mildly improved with albumin repletion, and she was empirically started on vedolizumab. Discussion: Given the absence of classic IBD findings, negative infectious and immunological testing, we present the first case of autoimmune cryptolytic enterocolitis, a histopathologic diagnosis of unclear etiology and pathogenesis. The patient has responded to vedolizumab infusions as an empiric treatment for an IBD-like entity. Nevertheless, supporting the autoimmune component of this entity, is a possible concomitant potential pathway of molecular mimicry in the setting of post-mycoplasma infection along with chronic high dose NSAID and OCP exposure.Figure 1.: Terminal Ileum and Sigmoid Colon with Diffuse Crypt Dropout.

Doxycycline as an antimalarial: Impact on travellers’ diarrhoea and doxycycline resistance among various stool bacteria – Prospective study and literature review

BackgroundAntibiotics predispose travellers to acquire multidrug-resistant bacteria, such as extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE). Although widely used in antimalarial prophylaxis, doxycycline has scarcely been studied in this respect. MethodsWe explored the impact of doxycycline on rates of traveller's diarrhoea (TD), ESBL-PE acquisition and, particularly, doxycycline co-resistance among travel-acquired ESBL-PE in a sample of 412 visitors to low- and middle-income countries.We reviewed the literature on traveller studies of doxycycline/tetracycline resistance among stool pathogens and the impact of doxycycline on TD rates, ESBL-PE acquisition, and doxycycline/tetracycline resistance. ResultsThe TD rates were similar for doxycycline users (32/46; 69.6%) and non-users (256/366; 69.9%). Of the 90 travel-acquired ESBL-PE isolates, 84.4% were co-resistant to doxycycline: 100% (11/11) among users and 82.3% (65/79) among non-users.The literature on doxycycline's effect on TD was not conclusive nor did it support a recent decline in doxycycline resistance. Although doxycycline did not increase ESBL-PE acquisition, doxycycline-resistance among stool pathogens proved more frequent for users than non-users. ConclusionsOur prospective data and the literature review together suggest the following: 1) doxycycline does not prevent TD; 2) doxycycline use favours acquisition of doxy/tetracycline-co-resistant intestinal bacteria; 3) although doxycycline does not predispose to travel-related ESBL-PE acquisition per se, it selects ESBL-PE strains co-resistant to doxycycline; 4) doxycycline resistance rates are high among stool bacteria in general with no evidence of any tendency to decrease.

The role of gastrointestinal pathogen polymerase chain reaction testing in liver transplant recipients hospitalized withdiarrhea.

Diarrhea is a common symptom among liver transplant (LT) recipients and can result in significant morbidity. The utility of PCR-based multiplex gastrointestinal (GI) pathogen panels in this population is unknown. We assessed incidence, predictors, and outcomes of GI PCR positivity among inpatients who underwent stool pathogen testing with the FilmArray multiplex GI PCR panel at our institution within 1 year following LT from April 2015 to December 2019. A total of 112 patients were identified. Of these, 14 (12.5%) had a positive PCR for any pathogen. Escherichia coli (n=9) and Norovirus (n=5) were the most common pathogens detected. Recipients with a positive PCR were significantly further from LT (median 74.5vs. 15.5 days, p<.01) and tested earlier during hospitalization (median 1.0vs. 9.0 days, p<.01). C. difficile was positive in 20.0% of patients with a positive PCR and 11.4% with a negative PCR. CMV viremia was observed in 11.6% of patients, all in the negative PCR group. Following a positive PCR, patients were more likely to have a change in antimicrobial regimen (71.4%vs. 28.6%, p=.02), a shorter length of stay (median 7.5vs. 17.5 days, p<.01), and a trend toward lower rates of readmission and colonoscopy within 30days. In hospitalized LT recipients with diarrhea, GI PCR pathogen identification was associated with the use of targeted antimicrobial therapy and a shorter length of stay. GI PCR testing should be considered early during admission and later in the post-LT period.

Clinical Metagenomics Is Increasingly Accurate and Affordable to Detect Enteric Bacterial Pathogens in Stool.

Stool culture is the gold standard method to diagnose enteric bacterial infections; however, many clinical laboratories are transitioning to syndromic multiplex PCR panels. PCR is rapid, accurate, and affordable, yet does not yield subtyping information critical for foodborne disease surveillance. A metagenomics-based stool testing approach could simultaneously provide diagnostic and public health information. Here, we evaluated shotgun metagenomics to assess the detection of common enteric bacterial pathogens in stool. We sequenced 304 stool specimens from 285 patients alongside routine diagnostic testing for Salmonella spp., Campylobacter spp., Shigella spp., and shiga-toxin producing Escherichia coli. Five analytical approaches were assessed for pathogen detection: microbiome profiling, Kraken2, MetaPhlAn, SRST2, and KAT-SECT. Among analysis tools and databases compared, KAT-SECT analysis provided the best sensitivity and specificity for all pathogens tested compared to culture (91.2% and 96.2%, respectively). Where metagenomics detected a pathogen in culture-negative specimens, standard PCR was positive 85% of the time. The cost of metagenomics is approaching the current combined cost of PCR, reflex culture, and whole genome sequencing for pathogen detection and subtyping. As cost, speed, and analytics for single-approach metagenomics improve, it may be more routinely applied in clinical and public health laboratories.

Potentially Pathogenic Organisms in Stools and Their Association With Acute Diarrheal Illness in Children Aged

Acute diarrheal illness (ADI) causes a substantial disease burden in high-income countries. We investigated associations between potentially pathogenic organisms in stools and ADI by polymerase chain reaction (PCR) in Australian children aged <2 years. Children in a community-based birth cohort had gastrointestinal symptoms recorded daily and stool samples collected weekly until their second birthday. Diarrhea was defined as ≥3 liquid or looser than normal stools within a 24-hour period. PCR assays tested for 11 viruses, 5 bacteria, and 4 protozoa. Detections of a new organism or of the same following at least 2 negative tests were linked to ADIs, and incidence rates and estimates of association with ADI were calculated. One hundred fifty-four children provided 11111 stool samples during 240 child-years of observation, and 228 ADIs were linked to samples. Overall, 6105 (55%) samples tested positive for a target organism. The incidence rate of 2967 new detections was 11.9 (95% confidence interval 11.4-12.3) per child-year, with 2561 (92%) new detections unrelated to an ADI. The relative risk of an ADI was 1.5-6.4 times greater for new detections of adenovirus, enterovirus, norovirus GII, parechovirus A, wild-type rotavirus, sapovirus GI/II/IV/V, Salmonella, Blastocystis, and Cryptosporidium, compared to when these were absent. Wild-type rotavirus, norovirus GII, sapovirus GI/II/IV/V, adenovirus 40/41, and Salmonella were associated with ADI in this age group and setting. However, high levels of asymptomatic shedding of potential pathogens in stools from children may contribute to diagnostic confusion when children present with an episode of ADI.

S2884 Pelvic Inflammatory Disease as an Unusual Cause of Ascites

Introduction: Pelvic inflammatory disease (PID) is an infection of the upper genital tract, including the uterus, fallopian tubes, and/or ovaries. Neisseria gonorrhea, Chlamydia trachomatis, and Mycoplasma genitalium are the most frequently isolated pathogens. Case Description/Methods: A 25-year-old female presented with an 8-day history of lower abdominal pain associated with fevers, chills, vomiting, and non-bloody diarrhea. Patient denied recent travel, changes in her diet, family history of Inflammatory Bowel Disease. Her abdomen was diffusely tender. Routine laboratory testing was unremarkable. CT scan of the abdomen and pelvis (Figure 1) showed focal small bowel mural thickening, concerning for gastroenteritis. COVID PCR, HIV antigen/antibody, blood cultures, Clostridium difficile toxin and stool pathogen PCR panel were all negative. Patient was presumed to have viral gastroenteritis and was discharged home. She was readmitted two days later for worsening nausea and vomiting. Laboratory testing was significant for WBC 12.7 x 109/L, potassium of 2.8 mEq, INR 1.7, CRP 19.24 mg/dL. A repeat CT abdomen and pelvis (Figure 2) showed a re-demonstration of marked wall thickening of the small bowel most consistent with enteritis, and the development of large loculated ascites in the mid abdomen and pelvis with peritoneal thickening and enhancement. Diagnostic paracentesis showed PMNs 990, RBCs 4000, SAAG < 1.1, total protein 3.7 g/dl, glucose 29 mg/dl, and LDH 1609 U/L. Peritoneal cultures grew Neisseria gonorrhea. Patient was discharged home on a two-week course of IV ceftriaxone, metronidazole and doxycycline with improvement in clinical symptoms. Repeat diagnostic imaging showed interval improvement and resolution of ascites. Discussion: Acute symptomatic PID presents with lower abdominal pain associated with fevers, chills, nausea, vomiting, vaginal discharge and/or intermenstrual bleeding. PID may present with RUQ pain in the setting of liver capsular inflammation, also known as perihepatitis i.e. Fitz-Hugh Curtis Syndrome. Perihepatitis occurs in about 10% of woman with acute PID. However, the development of ascites as a presenting complication of PID is very rare. In this case, the ascites fluid studies were not consistent with portal hypertension with a SAAG < 1.1. In addition, PMNs > 250 cells suggested bacterial peritonitis. Furthermore, per the Runyon’s criteria, this pattern resembled secondary bacterial peritonitis with a total protein >1 g/dL, glucose < 50 mg/dL, and LDH > upper limit of normal serum.Figure 1.: CT abdomen and pelvis on presentation showing small bowel mural thickening and enhancement.Figure 2.: CT abdomen and pelvis on representation showing large volume ascites with continued small bowel mural thickening and enhancement.

First reported case of safe and efficacious use of tocilizumab for treatment of hyperinflammatory syndrome associated with COVID‐19 in an allogeneic stem cell transplant patient

First reported case of safe and efficacious use of tocilizumab for treatment of hyperinflammatory syndrome associated with COVID‐19 in an allogeneic stem cell transplant patient

S2757 Vitamin K Deficiency in the Setting of Long-Term Blenderized Tube Feeds in a Teenager

INTRODUCTION: Severe, symptomatic presentation of nutritional deficiencies are uncommon in the current era. Vitamin K deficiency is classically seen in newborns and can present as early as 24 hours after birth and as late as up to 6 months. However, in pediatric patients with chronic comorbidities, vitamin K deficiency can also occur later in life with risk factors such as enteral feeding and recent antibiotic use. We describe a case of acquired vitamin K deficiency in a teenager on long term enteral nutrition. CASE DESCRIPTION/METHODS: A 17-year-old male with spinal muscular atrophy type 1, ventilator, and gastrostomy tube dependence, was admitted for coagulopathy noted during routine follow up after a diarrheal illness. He was treated with a short course of metronidazole for suspected small intestinal bacterial overgrowth as stool pathogens were negative. Physical examination revealed oozing from an anal fissure, tracheostomy, and gastrostomy sites. Laboratory studies revealed a prothrombin time (PT) of 114 s (normal: 9.4-12.5 s), partial thromboplastin time (PTT) 99.2 s (normal: 25.1-36.5 s) and international normalized ratio (INR) of 9.5 (normal: 1.1 or below). Fibrinogen and D-dimer were normal, ruling out disseminated intravascular coagulation. Factors V were normal at 94%, VIII more than 150%, VII low at 3%, and IX low at 11%. Mixing studies revealed deficiencies of the intrinsic and extrinsic pathways, and this, coupled with low factors VII and IX confirmed vitamin K deficiency. He received parenteral vitamin K which resolved his coagulopathy - PT 13.2 seconds, PTT 37.1 seconds, and INR of 1.2. His blenderized tube feeding regimen consisted of a base of Vivonex® Pediatric® mixed with baby foods and juice. This formulation did not meet the Dietary Reference Intake for vitamin K (44.2mcg/dL, recommended is 60-75mcg/dL), protein, phosphorus, calcium, zinc, folate, and essential fatty acids. He was discharged home on supplemental vitamin K, a multivitamin, protein supplement and, safflower oil. DISCUSSION: Our case highlights an important, yet frequently unrecognized differential of coagulopathy: vitamin K deficiency. This could be asymptomatic until the patient develops a bleeding diathesis. Clinicians should be aware that for pediatric patients on long-term blenderized tube feeds, it is essential to monitor micro and macronutrients on a regular basis.

S2797 First Case of Isolated Angioedema of the Bowel Caused by Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

INTRODUCTION: Visceral angioedema (VA) has been widely reported as a side-effect of angiotensin-converting enzyme inhibitors (ACEI). We report the first case of VA from NSAIDs. CASE DESCRIPTION/METHODS: An 80 y/o F with history of multiple abdominal surgeries, hypertension on lisinopril, and lumbago on aspirin 325 mg twice daily presented with acute epigastric pain, nausea, and vomiting. A CT scan showed moderate thickening and dilation of the distal small bowel (SB), without transition point. Symptoms resolved within days with supportive measures. One month later, while asymptomatic, a non-contrast MRI for pancreatic cyst surveillance showed normal SB. Two weeks after the MRI, her abdominal symptoms recurred. CT scan revealed multiple dilated, edematous fluid-filled stretches of SB, without transition point. Symptoms resolved spontaneously within days. Two months later, symptoms returned, with CT showing similar edema in the colon wall (Figure 1). Due to sharp angulations from edematous bowel, only a gastroscope could traverse the colon, with normal appearance of mucosa from the anus to the hepatic flexure. No SB evaluation was attempted due to SB edema. She improved after conservative management. She discontinued her lisinopril. One month later, symptoms recurred, with CT scan showing worsened bowel wall edema from prior CT (Figure 2). Labs were unremarkable for serum complement C4, C1 esterase inhibitor functional assay, extended stool pathogen panel, complete blood count, monoclonal gammopathy screen, and serum cytomegalovirus DNA. Aspirin was stopped. Symptoms abated within 24 hours. Five weeks later, while asymptomatic, her CT showed normalization of bowel wall (Figure 3). In no episode did the patient experience constitutional symptoms, dermatologic changes, dyspnea/wheezing, diarrhea, melena, or hematochezia. She had no new exposure to medications, travel, or dietary changes. In all cases where intravenous contrast was used, splanchnic vessels were patent. DISCUSSION: Episodic bowel obstructive symptoms associated with bowel thickening—and interval clinical improvement paralleling radiologic improvement of bowel thickening—illustrate the cadence of VA. As the VA occurred one month after stopping her ACEI, and symptoms resolved after stopping NSAIDs, it was likely triggered by her NSAID use. The shared pathogenesis and presentation of angioedema and enteropathy caused by NSAIDs provide a rationale for NSAID-induced VA. In patients without resolution of VA after stopping ACEI, NSAID cessation is the next step.Figure 1.: Computed tomography scan of the abdomen with intravenous contrast showed diffuse wall thickening of the descending and rectosigmoid colon. No transition point observed. Wall thickening, edema, and increased mucosal enhancement of multiple loops of the ileum and distal jejunum were observed, as well.Figure 2.: Computed tomography scan of the abdomen with intravenous contrast showed worsened evaluation compared to the previous scan. Diffuse wall thickening of the descending and rectosigmoid colon can be seen. No transition point can be seen. Wall thickening, edema, and increased mucosal enhancement of multiple loops of the ileum and distal jejunum were observed as well.Figure 3.: Five weeks after discontinuing her twice-daily aspirin, the patient underwent computed tomography scan with oral contrast (no intravenous contrast used), which showed interval resolution of the small bowel and colon wall thickening.

S1691 Colitis in a Rheumatologic Patient

INTRODUCTION: Although a known of cause diarrhea, the pyrimidine synthesis inhibitor leflunomide is a rare cause of overt pancolitis that presents a formidable diagnostic challenge. CASE DESCRIPTION/METHODS: A 46-year-old female with a medical history of psoriatic arthritis was admitted with a two-week history of progressive right upper-quadrant pain, frequent non-bloody diarrhea, tenesmus, and non-bloody emesis. Her immunosuppressant therapy included certolizumab for the past five years and leflunomide for the past 17 months. She denied use of other medications. Initial laboratory evaluation was significant for a mild leukocytosis, lipase of 476 U/L (normal: 12–61 U/L) and C-reactive protein of 50.8 mg/L (normal ≤8.0 mg/L). A stool pathogen panel including Clostridioides difficile was negative. RUQ ultrasound revealed cholelithiasis without cholecystitis. Computed-tomography imaging with contrast revealed no evidence of pancreatitis and mild wall thickening with mucosal hyperenhancement, consistent with ileocolitis (Figure A). A subsequent colonoscopy was notable for circumferential, contiguous inflammation throughout the colon but a normal terminal ileum. Sigmoidal inflammation was mild with a decreased vascular pattern, erythema, and mild friability (Figure B). Biopsy of the descending colon (Figure C) demonstrated surface erosion, crypt abscess (arrowhead) and destruction, and increased lamina propria inflammation without the chronic inflammation classically seen in inflammatory bowel disease. Cytomegalovirus immunostaining was negative. Symptoms persisted despite a three-day course of high-dose intravenous steroids. The decision was made to stop leflunomide, the disease-modifying anti-rheumatologic drug, due to select case reports documenting rare leflunomide-induced colitis. Symptoms improved within two weeks of drug cessation, with a reduction of stool frequency to two formed bowel movements daily, resolution of abdominal pain, and improvement of erythema on repeat flexible sigmoidoscopy. DISCUSSION: This case demonstrates the value of a comprehensive medication history and the diagnostic challenge of leflunomide-induced colitis. Patients with rheumatologic diseases are often on medications with adverse gastrointestinal effects, including biologics, steroids, NSAIDs and other immunomodulators. The lack of randomized studies, vague radiologic, endoscopic and histologic findings, as well as the variable onset after medication initiation makes leflunomide-induced colitis a challenging and rare diagnosis.Figure 1.: Abdominal CT with contrast revealing ileocolitis, mild wall thickening, and mucosal hyperenhancement of the entire colon, consistent with colitis.Figure 2.: Colonoscopy of sigmoid colon revealing mild inflammation with erythema, decreased vascular pattern, and mild friability.Figure 3.: Descending colon; biopsies show surface erosion, crypt abscesses and crypt destruction. There is also increased laminar propria inflammation (100x).

Positivity of Stool Pathogen Sampling in Pediatric Inflammatory Bowel Disease Flares and Its Association With Disease Course.

Acute exacerbations of inflammatory bowel disease (IBD) may involve enteric pathogen. We aimed to assess the frequency and outcomes of Clostridium difficille toxin (CDT) and non-CDT enteric infections in symptomatic pediatric patients with IBD. Patients' records were retrospectively searched for disease flares in which stool samples were collected for enteric pathogens. Each patient with a positive sample was matched with a patient with IBD flare and negative samples for analyzing 1-year outcomes following sampling. A total of 618 pediatric patients with IBD [Crohn's disease, n = 439 (71%), mean age at diagnosis 13.0 ± 3.4 years, girls, n = 264 (42.7%)] had 1048 stool samples during the study period (2001-2018). Of 914 bacterial cultures, 40 (4.3%) were positive, 30 (75%) of which, positive for Campylobacter jejuni. Of 393 samples for CDT, 28 (7.1%) were positive while parasitic infection rate was 21/529 (3.9%).Overall, 19 positive C jejuni cases and 19 positive CDT cases with matching controls were examined. During 12 months of follow-up, the mean number of disease flares and emergency room visits was higher among patients with positive CDT (1.5 ± 1.4 vs 0.5 ± 0.9, P = 0.019, 1.3 ± 1.5 vs 0.4 ± 0.8, P = 0.05, respectively) with a numeric increase of surgical interventions (3 vs 0, P = 0.08). There were no significant differences in disease outcomes between patients with C jejuni infections and matched controls. C difficile and C jejuni are the most common enteric infections among pediatric patients with IBD but only clostridial infection was associated with a more severe disease course within 12 months.

Pathogen-specific risk of seizure in children with moderate-to-severe diarrhoea: Case control study with follow-up.

To determine the pathogen-specific risk of seizure in under-five children hospitalised with moderate-to-severe diarrhoea (MSD) in rural settings. This was a prospective case-control study with follow-up, conducted in a sentinel facility of Global Enteric Multicenter Study in Mirzapur, a rural community of Bangladesh between 2007 and 2010. Children aged 0-59months who presented with MSD and seizure constituted the cases whereas those who did not have seizure comprised the controls. MSD was defined if the episodes were associated with dehydration or dysentery or required hospitalisation with diarrhoea or dysentery. All enrolled children were followed up at home within 50-90days of enrolment. A total of 64 cases and 128 randomly selected controls formed the analysable dataset. The result of logistic regression analysis after adjusting for potential confounders revealed that shigellosis (Shigella species, OR=5.34, 95% CI=2.37-12.04) particularly S. flexneri (OR=3.34, 95% CI=1.48-7.57), S. flexneri 6 (OR=23.24, 95% CI=2.79-193.85), S. sonnei (OR=6.90, 95% CI=2.34-19.85); norovirus (OR=6.77, 95% CI=1.69-27.11), fever (OR=16.75, 95% CI=1.81-154.70) and loss of consciousness (OR=35.25, 95% CI=1.71-726.20) were the independent risk factors for seizure in MSD children. At enrolment, cases had lower WHZ (P=0.006) compared to their peers, follow-up anthropometrics showed significant improvement in WHZ (P<0.001) and WAZ (P<0.05), whereas deterioration in HAZ (P<0.001) in both cases and controls. Childhood MSD episodes particularly due to Shigella and norovirus are often associated with seizure. Prompt identification and appropriate management of children with shigellosis may reduce occurrence and adverse consequences of seizure linked with MSD.

Glucagon-like Peptide 2 Concentrations Vary in Zambian Children During Diarrhoea, in Malnutrition and Seasonally.

ObjectivesGlucagon-like peptide 2 (GLP-2) is a 33 amino acid peptide hormone released from enteroendocrine L-cells following nutrient ingestion. It has been shown to exert trophic effects on the gut. We set out to measure GLP-2 concentrations in blood in children with diarrhoea and malnutrition.MethodsGLP-2 levels were measured in blood samples collected from 5 different groups of children (n = 324) at different time points: those with acute diarrhoea, during illness and 3 weeks after recovery; persistent diarrhoea and severe acute malnutrition; controls contemporaneous for diarrhoea; stunted children from the community; and controls contemporaneous for the stunted children. Stool biomarkers and pathogen analysis were carried out on the children with stunting.ResultsGLP-2 concentrations were higher during acute diarrhoea (median 3.1 ng/mL, interquartile range 2.1, 4.4) than on recovery (median 1.8, interquartile range 1.4, 3.1; P = 0.001), but were not elevated in children with persistent diarrhoea and severe acute malnutrition. In stunted children, there was a progressive decline in GLP-2 levels from 3.2 ng/mL (1.9, 4.9) to 1.0 (0.0, 2.0; P < 0.001) as the children became more stunted. Measures of seasonality (rainfall, temperature, Food Price Index, and Shiga toxin-producing Escherichia coli) were found to be significantly associated with GLP-2 concentrations in multivariable analysis. We also found a correlation between stool inflammatory biomarkers and GLP-2.ConclusionsIn diarrhoea, GLP-2 levels increased in acute but not persistent diarrhoea. Malnutrition was associated with reduced concentrations. GLP-2 displayed seasonal variation consistent with variations in nutrient availability.

Detection of C. difficile toxin as a model assay for performing fully automated high-throughput RT-PCR on clinical stool samples

BackgroundThe cobas® omni Utility Channel enables users to integrate lab-developed tests (LDTs) on the cobas® 6800 System to perform molecular diagnostics with high-throughput capacity and full automation. At present, there are no CE- or FDA-approved tests for stool pathogens on this system. To assess the performance of stool as a matrix, we evaluated the analytical and clinical performance of an LDT for detection of Clostridioides difficile (C. difficile) toxin B using the Utility Channel (C.diff_UTC). MethodsA 10% stool suspension prepared from liquid stool samples diluted in phosphate buffered saline was used for analysis. Limit of detection (LoD) was determined in six dilutions with 126 replicates/dilution. Clinical evaluation was performed using 514 predetermined patient stool samples from two study sites in Germany. The C.diff_UTC was compared with LC 480 amplification and an LDT or the R-BioPharm C. difficile assay. Discrepant results were further analyzed using the GeneXpert C. difficile assay. ResultsLimit of detection was 23.48 cfu/mL (95% Confidence Interval [CI]: 19.14–31.01) with inter-run variation of <2 cycle thresholds at 3 × and 10 × LoD. No cross-reactivity was observed with a panel of fecal organisms and pathogens. Bioinformatic analysis showed coverage of the major C. difficile toxinotypes by the primer/probe set. Clinical evaluation revealed sensitivity of 96.7% (95% CI: 88.7–99.6) and specificity of 99.3% (95% CI: 98.0–99.9) compared with the reference method; inhibition rate was 3.5% (18/514). ConclusionUsing a predesigned primer/probe set, the C.diff_UTC assay features analytical performance and clinical sensitivity and specificity comparable to currently available nucleic acid amplification tests (NAATs) and is suitable for high-throughput testing. This was a proof-of-concept study, indicating the cobas Utility Channel could likely be adapted for other clinically relevant stool pathogens in outbreak scenarios.

Pathogens causing diarrhoea among Bangladeshi children with malignancy: Results from two pilot studies.

BACKGROUNDDiarrhoea is a frequent symptom in children with cancer, and occurs due to a composite effect of underlying disease and immunosuppression consequent to therapy, malnutrition, and non-infective aetiologies such as mucositis. In a large proportion of cases, the aetiology of diarrhoea remains unknown but is often attributed to multiple pathogens including parasites.AIMTo identify and describe the pathogens causing diarrhoea in Bangladeshi children with cancer.METHODSTwo cross-sectional pilot studies were conducted involving paediatric oncology patients with diarrhoea. Stool samples were collected from children who were hospitalised with or without being treated with chemotherapy during the study period, and had diarrhoea at any stage during their admission. In the first study, stool samples were tested by conventional microbiological methods and by polymerase chain reaction for parasites, and by immunoassays for Clostridium difficile. In the second study, conventional microbiology was conducted for bacteria and parasites including an enzyme-linked immunosorbent assay for Cryptosporidium antigen, and in a subset, immunoassays for Clostridium difficile.RESULTSIn the first study Giardia lamblia was detected in 68.5% of samples, Entamoeba histolytica in 13%, Cryptosporidium in 5.6%, non-toxigenic C. difficile in 22.4%, and other bacteria in 5.2%. In the second study, E. histolytica was detected in 10% of samples, Cryptosporidium in 4.3%, G. lamblia in 1.4%, C. difficile in 5.1%, and other bacteria in 5.7% of samples.CONCLUSIONThese pilot data suggest that parasites are important aetiologies of diarrhoea in Bangladeshi children with malignancy. While molecular diagnostic tools detect an array of stool pathogens with greater sensitivity, conventional diagnostic methods are also useful.

Comparison of Multiplex Gastrointestinal Pathogen Panel and Conventional Stool Testing for Evaluation of Patients With HIV Infection.

BackgroundGastrointestinal pathogen panels (GPPs) are increasingly used to identify stool pathogens, but their impact in people with HIV (PWH) is unknown. We performed a retrospective cohort study comparing GPP and conventional stool evaluation in PWH.MethodsWe included all PWH who underwent GPP (Biofire Diagnostics; implemented September 15, 2015) or conventional testing, including stool culture, Clostridium difficile polymerase chain reaction testing, fluorescent smears for Cryptosporidium or Giardia, and ova and parasite exams (O&P) from 2013 to 2017. A total of 1941 specimens were tested, with 169 positive specimens detected in 144 patients. We compared result turnaround time, pathogen co-infection, antibiotic treatment, and treatment outcomes between positive specimens detected by conventional testing vs GPP.ResultsOverall, 124 patient samples tested positive by GPP, compared with 45 patient specimens by conventional testing. The GPP group demonstrated a higher co-infection rate (48.4% vs 13.3%; P < .001) and quicker turnaround time (23.4 vs 71.4 hours; P < .001). The GPP identified 29 potential viral infections that were undetectable by conventional stool tests. Unnecessary anti-infective therapy was avoided in 9 of 11 exclusively viral infections. Exclusively nonpathogenic parasites (n = 13) were detected by conventional stool tests, the majority of which were treated with metronidazole. There were no significant differences in clinical outcomes between groups.ConclusionsIn PWH, GPP implementation improved antibiotic stewardship through shorter turnaround times and detection of enteric viral pathogens.

Molecular and non-molecular approaches to etiologic diagnosis of gastroenteritis.

Gastroenteritis is a major cause of mortality and morbidity globally and rapid identification of the causative pathogen is important for appropriate treatment and patient management, implementation of effective infection control measures, reducing hospital length of stay, and reducing overall medical costs. Although stool culture and microscopic examination of diarrheal stool has been the primary method for laboratory diagnosis, culture-independent proteomic and genomic tests are receiving increased attention. Antigen tests for stool pathogens are routinely implemented as rapid and simple analytics whereas molecular tests are now available in various formats from high complexity to waived point-of-care tests. In addition, metagenomic next-generation sequencing stands poised for use as a method for both diagnosis and routine characterization of the gut microbiome in the very near future. Analysis of host biomarkers as indicators of infection status and pathogenesis may also become important for prediction, diagnosis, and monitoring of gastrointestinal infection. Here we review current methods and emerging technologies for the etiologic diagnosis of gastroenteritis in the clinical laboratory. Benefits and limitations of these evolving methods are highlighted.

Stool-Based Pathogen Detection Offers Advantages as an Outcome Measure for Water, Sanitation, and Hygiene Trials.

.Most health impact trials of water, sanitation, and hygiene use caregiver-reported diarrhea in children as the primary outcome; this measure is known to be subject to considerable bias, especially when used in unblinded trials. Detection of enteric pathogens in stool or fecal waste via multiplex molecular methods may offer advantages over—and is complementary to—caregiver-reported diarrhea because these measures are objective, on the causal pathway from exposures of interest to disease outcomes, and increasingly feasible in high-burden countries.

2649 A Case of Primary Intestinal Lymphangiectasia in an African American Adult Male With Intermittent Abdominal Pain and Diarrhea

INTRODUCTION: Primary intestinal lymphangiectasia is a rare type of protein losing enteropathy in which there is a localized or diffuse ectasia of the enteric lymphatic causing leakage of protein into the intestinal lumen. Here, we describe a case of Primary Intestinal Lymphangeictasia in a patient presenting with chronic intermittent abdominal pain and diarrhea. CASE DESCRIPTION/METHODS: Patient is a 56-year-old African-American male with history of COPD, DM, morbid obesity, GERD who presented to our office as a referral after hospitalization for for evaluation of abdominal pain and diarrhea. Patient was hospitalized for 3 day duration of epigastric pain and watery diarrhea. There, he was noted to have hypocalcemia, hypoalbuminemia, and trace urine proteinuria. Lactate was normal. CT abdomen pelvis showed nonspecific Jujenitis. He was treated empirically with Intravenous antibiotics and discharged home. During follow up visits, initial comprehensive workup for inflammatory bowel disease, celiac disease, stool pathogens, thyroid panel, lipid panel, Alpha-1-Antitrypsin stool clearance, and HIV were all unremarkable. Patient subsequently underwent colonoscopy and EGD. Colonoscopy revealed sigmoid diverticulosis and internal hemorrhoids. EGD revealed nonspecific jejunitis. He had yet another hospitalization for worsening similar acute abdominal pain. During his second hospitalization, labs showed mild leukocytosis, CT abdomen and pelvis revealed jejunal edema. He was taken for diagnostic laparoscopy which only showed mild ascites and thickening of the jejunum. Surgical pathology unfortunately was inconclusive. Patient followed up again as an outpatient and underwent small capsule endoscopy which revealed lymphangiectasia at the jejunum. Patient was referred to a dietitian where he was placed on high protein and Medium chain triglycerides diet. DISCUSSION: Primary Intestinal Lymphangeictasia is a rare cause of protein losing enteropathy that can manifest as non-specific abdominal pain and diarrhea. In this case, the patient had chronic intermittent abdominal pain and diarrhea which required capsule endoscopy in order to diagnose and was missed on surgical pathology. Much like an Inflammatory Bowel disease which can take several studies and biopsies in order to diagnose, albeit different pathophysiology, Primary intestinal lymphaniectasia is a rare cause of abdominal pain that should be on the differential when evaluating chronic intermittent severe abdominal pain and diarrhea of unknown etiology.