Colitis amebiana fulminante con desenlace fatal en un paciente con probable infección por SARS-CoV-2 / Fulminant amebic colitis with fatal outcome in a patient with probable SARS-CoV-2 infection

RESUMEN Se reporta el caso de un varón de 62 años quien presentó tos y dolor abdominal por dos semanas, con hallazgos tomográficos pulmonares compatibles con probable infección por SARS-CoV-2, que recibió tempranamente corticoterapia a dosis altas y de manera ambulatoria. El paciente presentó evolución tórpida, fue hospitalizado y falleció en el posoperatorio inmediato por un cuadro de abdomen agudo quirúrgico. El estudio anatomopatológico mostró estructuras parasitarias con características compatibles con amebas, como causa de una colitis aguda fulminante complicada, con perforación múltiple y peritonitis aguda. La colitis aguda fulminante por amebiasis intestinal en el contexto de un paciente con probable COVID-19 no había sido reportada en el Perú. Resulta importante resaltar la presentación fulminante con desenlace fatal de esta infección parasitaria prevalente en nuestro medio, en el contexto del uso de corticoides ante una probable infección pulmonar por COVID-19.

ABSTRACT We report the case of a 62-year-old male with cough and abdominal pain for two weeks, associated with pulmonary tomographic findings compatible with probable infection by SARS-CoV-2, and who received high doses of early corticotherapy as an outpatient. The patient showed clinical deterioration, was hospitalized and died in the immediate postoperative period due to acute surgical abdomen. The anatomopathological study showed parasitic structures with characteristics compatible with amebae, which was pointed to as the cause of a complicated acute fulminant colitis, with multiple perforations and acute peritonitis. Acute fulminant colitis due to intestinal amebiasis in the context of a patient with probable COVID-19 had not been previously reported in Peru. It is important to highlight the fulminant presentation with fatal outcome of this prevalent parasitic infection, in the context of corticosteroids use in a probable SARS-CoV-2 pulmonary infection.

The differentiation of amebic colitis from inflammatory bowel disease on endoscopic mucosal biopsies.

Background: Intestinal amebiasis is one of the important differential diagnoses of Inflammatory Bowel Disorders in areas where it is highly prevalent. Aim: Studies comparing the clinical, endoscopic and histological features of these disorders have never been done, so we undertook this study. Materials and Methods: A retrospective study comparing mucosal biopsies of 14 consecutive cases of intestinal amebiasis with 14 cases of Ulcerative colitis and 12 cases of Crohn’s disease. A total of 65 biopsies from patients with amebiasis, 56 biopsies from patients with Crohn’s disease and 65 biopsies of patients with Ulcerative colitis were reviewed. Results and Conclusions: Discrete small ulcers less than 2 cm in diameter in the cecum or rectosigmoid, with intervening normal mucosa, were the most common finding on endoscopy in patients with amebiasis. On histology, necrotic material admixed with mucin, proteinaceous exudate and blood clot lining ulcers, significant surface epithelial changes such as shortening and tufting adjacent to sites of ulceration, mild chronic inflammation extending into the deep mucosa and mild architectural alteration were features of amebiasis. Trophozoite forms of ameba were seen in the necrotic material lining sites of ulceration or lying separately, as well as over intact mucosa. Necrotic material lining ulcers was less common in IBD, but chronic inflammation, crypt abscess formation and architectural alteration were more severe.

Perfuração do colo por colite amebiana invasiva durante terapia anti-TNF para espondiloartrite / Colonic perforation due to invasive amebic colitis during anti-TNF therapy for spondyloarthritis

O bloqueio do TNF tem tido sucesso no tratamento de algumas doenças reumáticas, como a espondiloartrite. Relatam-se muitas complicações infecciosas com a terapia anti-TNF, principalmente infecções bacterianas, micobacterianas, virais e fúngicas. A Entamoeba histolytica é um protozoário extracelular que causa principalmente colite e abscesso hepático, sendo que a perfuração intestinal é uma complicação rara, com alta mortalidade. O TNF é considerado o principal mediador da imunidade celular contra a amebíase. Inicialmente, é quimiotático para a E. histolytica, potencializando sua adesão ao enterócito por meio da lectina galactose-inibível, e depois ativando os macrófagos para matarem a ameba pela liberação de NO; assim, o bloqueio do TNF poderia ser prejudicial, aumentando a virulência amebiana. Descreve-se o caso de uma mulher de 46 anos com espondiloartrite que apresentou uma perfuração do colo por colite amebiana invasiva durante uso de anti-TNF.

TNF blockade has been successful in the treatment of some rheumatic diseases such as spondyloarthritis. Many infectious complications have been reported with anti-TNF therapy, mainly bacterial, mycobacterial, viral and fungal infections. Entamoeba histolytica is an extracellular protozoan parasite that mainly causes colitis and hepatic abscess; bowel perforation is an uncommon complication with high mortality. TNF is considered the principal mediator of cell immunity against amebiasis. Initially, it is chemotactic to E. histolytica, enhancing its adherence to enterocyte via galactose inhibitable lectin, and then activating macrophages to kill ameba though the release of NO, so that TNF blocking could be harmful, increasing amebic virulence. We describe the case of a 46-year-old woman with spondyloarthritis who presented a colonic perforation due to invasive amebic colitis during anti-TNF use.

G protein signaling in the parasite Entamoeba histolytica

The parasite Entamoeba histolytica causes amebic colitis and systemic amebiasis. Among the known amebic factors contributing to pathogenesis are signaling pathways involving heterotrimeric and Ras superfamily G proteins. Here, we review the current knowledge of the roles of heterotrimeric G protein subunits, Ras, Rho and Rab GTPase families in E. histolytica pathogenesis, as well as of their downstream signaling effectors and nucleotide cycle regulators. Heterotrimeric G protein signaling likely modulates amebic motility and attachment to and killing of host cells, in part through activation of an RGS-RhoGEF (regulator of G protein signaling-Rho guanine nucleotide exchange factor) effector. Rho family GTPases, as well as RhoGEFs and Rho effectors (formins and p21-activated kinases) regulate the dynamic actin cytoskeleton of E. histolytica and associated pathogenesis-related cellular processes, such as migration, invasion, phagocytosis and evasion of the host immune response by surface receptor capping. A remarkably large family of 91 Rab GTPases has multiple roles in a complex amebic vesicular trafficking system required for phagocytosis and pinocytosis and secretion of known virulence factors, such as amebapores and cysteine proteases. Although much remains to be discovered, recent studies of G protein signaling in E. histolytica have enhanced our understanding of parasitic pathogenesis and have also highlighted possible targets for pharmacological manipulation.

A case of amebic colitis mimicking pseudomembranous colitis / 대한내과학회지

No abstract available.

A case of amebic colitis in a renal-transplant recipient / 대한내과학회지

Intestinal amoebiasis is caused by the protozoan Entamoeba histolytica. Amoebic colitis is usually acquired by ingesting contaminated food or water, but it can be associated with cell-mediated immunosuppression in organ-transplant recipients. We present a case of invasive amoebic colitis in a kidney-transplant recipient who was treated successfully with metronidazole and adjusted immunosuppressive therapy. The patient was a 49-year-old man who had undergone renal transplantation 15 years earlier. He complained of diarrhea accompanied by mild lower abdominal pain over five weeks, and the diagnosis of amoebic colitis was made with a colonoscopic biopsy. The colonoscopic findings showed multiple, round, scattered ulcerations throughout the colon, and trophozoites of E. histolytica were identified in the base of these ulcers. We treated his colitis with metronidazole and a reduction in immunosuppressive therapy.

Clinical Characteristics of Amebic Colitis as Diagnosed by using Colonoscopic Findings

PURPOSE: Nowadays, with improvements in hygiene and in the sewage system, the prevalence of amebic colitis in Korea is declining. However, amebic colitis still occurs every year. We investigated the clinical features of current patients with amebic colitis and compared the results with those for a past endemic period in Korea. METHODS: From June 2000 to June 2005, 10 patients were diagnosed in the Digestive endoscopy center of Song Do colorectal hospital as having amebic colitis. We evaluated their medical histories, clinical characteristics, and colonoscopic findings. RESULTS: The male-to-female ratio was 1.5 : 1. The mean age was 38.4+/-11.4 years. The mean diagnostic period from occurrence of symptoms to diagnosis was 20.4+/-17.5 days. The clinical symptoms of amebic colitis were diarrhea (80%), bloody stool (70%), mucoid stool (60%), abdominal pain (50%), fever, weight loss, nausea, and fatigue. Seven patients (70%) had a history of travel, and six of those seven patients had taken trips abroad. The foreign areas of travel included India (50%), Indonesia (28.6%), and Japan (16.7%). The diagnostic methods were colonoscopic biopsies to detect trophozoites of Entameba histolytica (90%) and serologic tests for the anti-ameba antibody (10%). The most common colonic locations of the lesions were the cecum (80%) and the rectum (80%). Another was the ascending colon (30%); pan-colonic involvement was also seen (10%). CONCLUSIONS: In the past, the cause of amebic colitis in Korea was poor hygiene. Nowadays, however, travel to amebiasis-endemic areas may be the most important cause. Therefore, the travel history of diarrheal patients is an important diagnostic factor in cases of amebic colitis and a differential diagnosis factor in cases of inflammatory bowel disease.

Three Cases of Amebic Colitis Misdiagnosed as T.B. Colitis

Nowadays, inflammatory bowel disease, such as ulcerative colitis and Crohn's disease, is increasing; however, infectious colitis, such as amebic colitis, is decreasing, so many doctors are not apt to be interested in infectious colitis. In addition, recently amebic colitis has been relatively rare in Korea, and the colonoscopic and the pathologic findings of amebic colitis are very similar to those of other inflammatory bowel diseases. As a consequence, the diagnosis is very difficult if the cyst or the trophozoite of the ameba is not found in the stool examination or in the tissue pathology. The authors experienced three cases in which initial diagnoses of tuberculous colitis, ulcerative colitis, and a simple ulcer were made based on colonoscopic and X-ray findings. However a colonoscopic biopsy revealed a trophozoite form of ameba in the tissue. Hence, a diagnosis of amebic colitis could be made with confidence. Based on these results, we insist that infectious colitis should be included in the differential diagnosis when making a diagnosis of inflammatory bowel disease. In addition, it is extremely important to consider all kinds of infectious colitis, such as amebic colitis.

Atypical clinical manifestations of amebic colitis

Amebic colitis is a disease revealing diverse clinical manifestations and endoscopic gross features and often confused with other types of colitis. In case of misdiagnosis as an idiopathic inflammatory bowel disease or delayed recognition of intestinal amebiasis, an undesirable outcome may occur resulting from erroneous administration of steroids or delayed antiamebic treatment. To demonstrate the pitfalls in the diagnosis and treatment of intestinal amebiasis, 3 cases of amebic colitis with atypical clinical manifestations are presented in this paper. In conclusion, despite the low sensitivities of routine stool examination for parasite and histopathologic confirmation in biopsy specimen, every effort must be made to find amebic trophozoites either in fresh stool or biopsy specimens for prompt and correct diagnosis of amebic colitis when we manage patients with chronic intestinal ulcerations, even though their clinical course and endoscopic findings are not typical of amebiasis. Moreover, following initial successful anti-amebic therapy, more careful clinical, endoscopical, and parasitological follow-up should be done for the early detection of recurrence.

Two cases of imported amebiasis in a rural district of Shimane prefecture, Japan / 日本農村医学会雑誌

We treated two elderly patients who contracted amebiasis in a foreign country. They ate a watermelon in Peking, the People's Republic of China. From their account, the watermelon was considered the most probable source of infection.<BR>In Case 1, the patient complained of acute nausea, vomiting, diarrhea and unconsciousness following severe dehydration. The trophozoites of <I>Entamoeba histolytica</I> were found by stool examination. The treatment with metronidazole was not so effective in Case 1 patient with fulminating amebic colitis. In Case 2, he had no subjective symptoms, but the cysts of <I>Entamoeba histolytica</I> were found by stool examination.<BR>Recently, traveling abroad has become popular. The number of travelers has been increasing in Japan from not only urban districts but also rural districts. Therefore, it is necessary to exercise strict rigilance over the imported protozoan parasites and possible mass outbreak of amebiasis in tour groups.