Abnormal computed tomography findings among children with viral gastroenteritis and symptoms mimicking acute appendicitis

POCUS for Infectious Enteritis-A Retrospective Case Series Analysis

INTRODUCTION

The abdominal pain associated with diarrhea can be difficult to distinguish from appendicitis. We present a case series of all children found on pediatric emergency department point-of-care ultrasound (POCUS) to have right-sided bowel wall edema.

METHODS

Over the study period June 2020 through September 2023, POCUS images were collected by a pediatric emergency physician with 6 years of experience with POCUS. Children found to have small bowel wall edema on POCUS were identified, and hospital charts were reviewed.

RESULTS

One hundred thirteen children were found on POCUS to have right-sided small bowel wall edema. Thirty-one (27%) were referred by their pediatrician or urgent care provider to evaluate for appendicitis. Seventy-eight children (69%) provided stool samples. Of those, 58% resulted Campylobacter , 8% Salmonella , and 8% Shigella . Forty (35%) were discharged after POCUS without further evaluation. One child in our case series was subsequently diagnosed with uncomplicated appendicitis. To date, no child in the series has subsequently been diagnosed with inflammatory bowel disease.

CONCLUSIONS

Enteritis can initially be difficult to distinguish on clinical grounds from acute appendicitis. Bowel wall edema on POCUS in a child without sonographic signs of appendicitis strongly suggests bacterial enteritis. Early POCUS demonstrating enteritis without signs of appendicitis may decrease hospital resource usage.

Complicated appendicitis wrongly diagnosed as nonspecific diarrhea: ways to decrease this continuous threat

BACKGROUND

The diagnostic assessment of right lower quadrant pain in children and adolescents is still a challenge. The aim of this study was to analyze the cases of complicated appendicitis wrongly diagnosed as nonspecific diarrhea, and based on the information obtained suggest a clear and simple policy in order to decrease misdiagnosis in the future.

METHODS

Three groups of patients were analyzed: children who underwent appendectomy (group 1); those with gastroenteritis (group 2), and those who underwent appendectomy following hospitalization under the wrong diagnosis of gastroenteritis (group 3).

RESULTS

Group 3 presented a more prolonged and complicated clinical course, higher fever, diffuse abdominal pain, repeat vomiting, higher C-reactive protein values, longer surgery duration and recovery.

CONCLUSIONS

When the etiology of right lower quadrant abdominal pain is not immediately evident and associated with atypical diarrhea, high fever, repeat vomiting, and significantly increased CRP values, early surgical consultation is required. If the clinical findings are unclear, an abdominal US should be performed as soon as possible. A limited abdominal computed tomography scan CT should follow those cases not resolved by history, physical examination, blood tests, and abdominal ultrasound.

Gastrointestinal Manifestations of Immunodeficiency: Imaging Spectrum

There is a wide spectrum of hereditary and acquired immunodeficiency disorders that are characterized by specific abnormalities involving a plethora of humoral, cellular, and phagocytic immunologic pathways. These include distinctive primary immunodeficiency syndromes due to characteristic genetic defects and secondary immunodeficiency syndromes, such as AIDS from HIV infection and therapy-related immunosuppression in patients with cancers or a solid organ or stem cell transplant. The gut mucosa and gut-associated lymphoid tissue (the largest lymphoid organ in the body), along with diverse commensal microbiota, play complex and critical roles in development and modulation of the immune system. Thus, myriad gastrointestinal (GI) symptoms are common in immunocompromised patients and may be due to inflammatory conditions (graft versus host disease, neutropenic enterocolitis, or HIV-related proctocolitis), opportunistic infections (viral, bacterial, fungal, or protozoal), or malignancies (Kaposi sarcoma, lymphoma, posttransplant lymphoproliferative disorder, or anal cancer). GI tract involvement in immunodeficient patients contributes to significant morbidity and mortality. Along with endoscopy and histopathologic evaluation, imaging plays an integral role in detection, localization, characterization, and distinction of GI tract manifestations of various immunodeficiency syndromes and their complications. Select disorders demonstrate characteristic findings at fluoroscopy, CT, US, and MRI that permit timely and accurate diagnosis. While neutropenic enterocolitis affects the terminal ileum and right colon and occurs in patients receiving chemotherapy for hematologic malignancies, Kaposi sarcoma commonly manifests as bull's-eye lesions in the stomach and duodenum. Imaging is invaluable in treatment follow-up and long-term surveillance as well. Online supplemental material is available for this article. ^©RSNA, 2022.

Imaging of abdominal and pelvic infections in the cancer patient

Infections are the most commonly encountered complications in patients with cancer. The classical signs and symptoms of infections are often not present in this patient population, which makes the diagnosis more challenging. Host factors play a major role in the development and prognosis of infections in cancer patients; these can be related to the underlying type of malignancy (solid organ versus hematological), tumor burden, anatomic obstruction, altered integrity of barriers (skin or mucosa), treatment-related factors (from chemotherapy, radiation treatment, surgery, interventional procedures, and/or medical device placement) and the degree of immunosuppression. This article reviews common, as well as less common, imaging manifestations of infections and their potential mimics in the abdomen and pelvis in cancer patients and discusses their differentiating features, with the role of imaging in various organs in the abdomen and pelvis taking into consideration relevant clinical background information and the main risk factors.

Norovirus infection in solid organ transplant recipients: a single-center retrospective study

BACKGROUND

Norovirus (NoV) is gaining recognition as an important cause of diarrhea among solid organ transplant (SOT) recipients, but existing studies have been limited by a small sample size.

METHODS

We conducted a retrospective study of all adult SOT recipients diagnosed with NoV between 2006 and 2013 and compared their data to that of adult SOT recipients with diarrhea who tested negative for NoV during that time.

RESULTS

A total of 192 patients with diarrhea had stool NoV testing as part of their work-up during the study period; of these patients, 35% (67) tested positive for NoV. Of patients with diarrhea without NoV, Clostridium difficile (25%) and cytomegalovirus (12%) were the most commonly identified infectious cause of diarrhea. Diarrheal duration was significantly protracted in NoV patients, with an average of 241 days vs 75 days in the control group (P=.0007). One patient death and 2 graft failures were related to the NoV illness within the first month after the onset of diarrhea, and 30% of NoV patients had a ≥20% increase in creatinine within 1 year of diagnosis. These outcomes did not differ significantly from those of SOT patients with diarrhea in the non-NoV group.

CONCLUSIONS

NoV is a common cause of diarrhea among SOT recipients at our institution and is responsible for a very prolonged course of chronic diarrhea.

Randomized, double-blinded clinical trial for human norovirus inactivation in oysters by high hydrostatic pressure processing

Contamination of oysters with human noroviruses (HuNoV) constitutes a human health risk and may lead to severe economic losses in the shellfish industry. There is a need to identify a technology that can inactivate HuNoV in oysters. In this study, we conducted a randomized, double-blinded clinical trial to assess the effect of high hydrostatic pressure processing (HPP) on Norwalk virus (HuNoV genogroup I.1) inactivation in virus-seeded oysters ingested by subjects. Forty-four healthy, positive-secretor adults were divided into three study phases. Subjects in each phase were randomized into control and intervention groups. Subjects received Norwalk virus (8FIIb, 1.0 × 10(4) genomic equivalent copies) in artificially seeded oysters with or without HPP treatment (400 MPa at 25°C, 600 MPa at 6°C, or 400 MPa at 6°C for 5 min). HPP at 600 MPa, but not 400 MPa (at 6° or 25°C), completely inactivated HuNoV in seeded oysters and resulted in no HuNoV infection among these subjects, as determined by reverse transcription-PCR detection of HuNoV RNA in subjects' stool or vomitus samples. Interestingly, a white blood cell (granulocyte) shift was identified in 92% of the infected subjects and was significantly associated with infection (P = 0.0014). In summary, these data suggest that HPP is effective at inactivating HuNoV in contaminated whole oysters and suggest a potential intervention to inactivate infectious HuNoV in oysters for the commercial shellfish industry.

Norovirus gastroenteritis causes severe and lethal complications after chemotherapy and hematopoietic stem cell transplantation

Norovirus (NV) infections are a frequent cause of gastroenteritis (GE), but data on this disease in immunocompromised patients are limited. We analyzed an NV outbreak, which affected immunosuppressed patients in the context of chemotherapy or HSCT. On recognition, 7 days after admission of the index patient, preventive measures were implemented. Attack rates were only 3% (11/334) and 10% (11/105) among patients and staff members, respectively. The median duration of symptoms was 7 days in patients compared with only 3 days in staff members (P = .02). Three patients died of the NV infection. Commonly used clinical diagnostic criteria (Kaplan-criteria) were unsuitable because they applied to 11 patients with proven NV-GE but also to 15 patients without NV-GE. With respect to the therapeutic management, it is important to differentiate intestinal GVHD from NV-GE. Therefore, we analyzed the histopathologic patterns in duodenal biopsies, which were distinctive in both conditions. Stool specimens in patients remained positive for NV-RNA for a median of 30 days, but no transmission was observed beyond an asymptomatic interval of 48 hours. NV-GE is a major threat to patients with chemotherapy or HSCT, and meticulous measures are warranted to prevent transmission of NV to these patients.