Characteristics of endoscopic and pathological findings of amebic colitis

Amoebic colitis insufficient to metronidazole monotherapy

Amoebic colitis is a parasitic gastrointestinal disease caused by Entamoeba histolytica (E. histolytica). In Japan, metronidazole (MNZ) monotherapy is often used and most cases are effective. However, we report a case of MNZ-insufficient amoebic colitis caused by residual cysts. A 73-year-old man had been staying in Southeast Asia for over a decade. He had undergone a screening colonoscopy and ulcerative lesions were observed in the cecum, and a biopsy confirmed amoeba parasites. The patient was treated with MNZ monotherapy. However, he forgot to take the medicine for several days, and the ulcerative lesions persisted. The patient was referred to our facility, and we performed a colonoscopy and confirmed trophozoites. Since we considered that previous treatment failure was due to the low oral dosage, we re-prescribed MNZ. A colonoscopy after 6 months showed that the ulcerative lesions persisted. We clinically diagnosed MNZ-insufficient amoebic colitis caused by residual cysts and prescribed MNZ and paromomycin (PRM) each for 10 days. One year later, no ulcerative lesions were observed. MNZ-insufficient amoebic colitis should be considered, when ulcerative lesions remain after MNZ administration and PRM is effective drug against cysts, and we propose a combination therapy of PRM to MNZ.

Decision tree-based learning and laboratory data mining: an efficient approach to amebiasis testing

BACKGROUND

Amebiasis represents a significant global health concern. This is especially evident in developing countries, where infections are more common. The primary diagnostic method in laboratories involves the microscopy of stool samples. However, this approach can sometimes result in the misinterpretation of amebiasis as other gastroenteritis (GE) conditions. The goal of the work is to produce a machine learning (ML) model that uses laboratory findings and demographic information to automatically predict amebiasis.

METHOD

Data extracted from Jordanian electronic medical records (EMR) between 2020 and 2022 comprised 763 amebic cases and 314 nonamebic cases. Patient demographics, clinical signs, microscopic diagnoses, and leukocyte counts were used to train eight decision tree algorithms and compare their accuracy of predictions. Feature ranking and correlation methods were implemented to enhance the accuracy of classifying amebiasis from other conditions.

RESULTS

The primary dependent variables distinguishing amebiasis include the percentage of neutrophils, mucus presence, and the counts of red blood cells (RBCs) and white blood cells (WBCs) in stool samples. Prediction accuracy and precision ranged from 92% to 94.6% when employing decision tree classifiers including decision tree (DT), random forest (RF), XGBoost, AdaBoost, and gradient boosting (GB). However, the optimized RF model demonstrated an area under the curve (AUC) of 98% for detecting amebiasis from laboratory data, utilizing only 300 estimators with a max depth of 20. This study highlights that amebiasis is a significant health concern in Jordan, responsible for 17.22% of all gastroenteritis episodes in this study. Male sex and age were associated with higher incidence of amebiasis (P = 0.014), with over 25% of cases occurring in infants and toddlers.

CONCLUSIONS

The application of ML to EMR can accurately predict amebiasis. This finding significantly contributes to the emerging use of ML as a decision support system in parasitic disease diagnosis.

Amoebic colitis-A diagnostic challenge on endoscopy: Case report

Amoebic colitis remains a diagnostic challenge on colonoscopy given that its features resemble that of inflammatory bowel disease. We describe a similar case of a 66 years old male patient with multiple comorbidities including morbid obesity, end-stage renal disease requiring haemodialysis, IHD with PCI, T2DM, HTN and new onset dry cough for which he received a short course of steroids. He presented to the colorectal clinic with bleeding and mucus discharge per-rectum with no other symptoms related to bowel and non-specific colonoscopy findings with amoebic colitis only confirmed on histological diagnosis. The patient was commenced on a course of Metronidazole and followed up on first and sixth month after treatment where he remained well and reported no further symptoms.

A case report of refractory amebic colitis and literature review

RATIONALE

Amebic colitis has been less prevalent in recent times in China, and the similarity of its symptoms to those of inflammatory bowel disease (IBD) results in the difficulty of early identification and diagnosis.

PATIENT CONCERNS

A 31-year-old male who exhibited intermittent diarrhea and hematochezia was highly suspected as IBD initially. Despite the partial relief of symptoms following the administration of mesalamine, the endoscopic ulcers remained largely unchanged.

DIAGNOSES

Two years after the onset of mesalamine therapy, amebic cysts were detected in stool microscopy and trophozoites were found on the surface of cecal ulcers. The patient was then diagnosed with amebic colitis.

INTERVENTIONS

After 2 rounds of standardized metronidazole treatment, amebic colitis remained refractory until diloxanide was administered.

OUTCOMES

The patient remained asymptomatic, and the mucosa of colon was normal during the annual follow-up.

LESSONS

Individuals newly diagnosed with IBD should undergo essential screening for amebiasis. And the use of steroids should be taken with caution, especially in cases where the effect of mesalamine is limited. For symptomatic intestinal amebiasis, even after the administration of tissue amebicides, the continued use of luminal amebicides is necessary to prevent recurrence.

Infectious Mimics of Inflammatory Bowel Disease

Distinguishing inflammatory bowel disease (IBD) from its mimics remains a diagnostic challenge for surgical pathologists. Several gastrointestinal infections produce inflammatory patterns that overlap with typical findings of IBD. Although stool culture, PCR, and other clinical assays may identify infectious enterocolitides, these tests may not be performed or the results may be unavailable at the time of histologic evaluation. Furthermore, some clinical tests, including stool PCR, may reflect past exposure rather than ongoing infection. It is important for surgical pathologists to be knowledgeable about infections that simulate IBD in order to generate an accurate differential diagnosis, perform appropriate ancillary studies, and prompt clinical follow-up. This review covers bacterial, fungal, and protozoal infections in the differential diagnosis of IBD.

Entamoeba histolytica-associated proctitis and ileitis mimicking Crohn's disease-A case report

We report about a proctitis and ileitis terminalis, leading to the misdiagnosis of Chron's disease, in a male patient who has sex with men. Molecular multiplex analysis identified Entamoeba histolytica as the underlying cause. We provide diagnostic images, clues and pitfalls for diagnosis of E. histolytica associated proctitis.

Diversity and Plasticity of Virulent Characteristics of Entamoeba histolytica

The complexity of clinical syndromes of amebiasis, caused by the parasite Entamoeba histolytica, stems from the intricate interplay between the host immune system, the virulence of the invading parasite, and the surrounding environment. Although there is still a relative paucity of information about the precise relationship between virulence factors and the pathogenesis of Entamoeba histolytica, by accumulating data from clinical and basic research, researchers have identified essential pathogenic factors that play a critical role in the pathogenesis of amebiasis, providing important insights into disease development through animal models. Moreover, the parasite's genetic variability has been associated with differences in virulence and disease outcomes, making it important to fully understand the epidemiology and pathogenesis of amebiasis. Deciphering the true mechanism of disease progression in humans caused by this parasite is made more difficult through its ability to demonstrate both genomic and pathological plasticity. The objective of this article is to underscore the heterogeneous nature of disease states and the malleable virulence characteristics in experimental models, while also identifying persistent scientific issues that need to be addressed.