Fulminant amebic colitis. A morphologic study of four cases

Updates on the worldwide burden of amoebiasis: A case series and literature review

BACKGROUND

Amoebiasis is an intestinal and tissue parasitic infection caused by the protozoan Entamoeba histolytica. Despite significant medical importance and worldwide dispersion, little is known about the epidemiology and distinct geographical distribution of various clinical forms of amoebiasis in the world. In this study, we present an amoebiasis case series referred to Avicenne Hospital (Bobigny, France) from 2010 to 2022 followed by an overview of the released literature to explore diverse clinico-pathology of amoebiasis and to update the actual epidemiological situation of this parasitosis worldwide.

METHODS

The referred patients underwent a combination of clinical and parasitological examinations and imaging. The study was followed by an overview of released literature performed based on PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guideline.

RESULTS

A total of 15 patients with amoebiasis were diagnosed with an average age of 48.5 years old at the occurrence time of infection. Men (78%) were the most affected patients. Most of the cases were reported following a trip to endemic regions, such as Mali, India, Nepal, Algeria, Cameroon or Congo. All of the processed patients exhibited a hepatic amoebiasis. Amoebic abscess was observed in all cases with an average size of 6.3 cm. Of these patients, seven cases (46.7%) benefited from drainage following a risk of rupture or superinfection of the abscess. A compilation of findings extracted from 390 scientific publications via seven major medical databases, allowed us to update the main epidemiological and clinical events that has led to the current worldwide expansion of amoebiasis. We presented a clinical and epidemiological overview of the amoebiasis accompanied with a worldwide illustrative map displaying the current distribution of known amoebiasis foci in each geographical ecozone of Asia, Europe, Africa, Americas, and Australia.

CONCLUSIONS

Although Metropolitan France is not known as an endemic region of amoebiasis, amoebic liver abscess was the most frequent clinical form observed among our 15 patients processed. Most of infected patients had a history of travel to or lived-in endemic areas before arriving in France.

Fulminant amoebic colitis: a clinicopathological study of 30 cases

AIMS

To review the clinical and pathological factors associated with fulminant amoebic colitis (FAC) requiring colonic resection and its outcome.

METHODS

We retrospectively identified adult patients admitted to our centre between June 2007 and December 2011 with FAC who underwent colonic resection and were diagnosed with amoebic colitis based on the presence of trophozoites on histological examination. The clinical details were extracted from the medical notes and correlated with the pathological findings.

RESULTS

Thirty patients (18 men and 12 women) met the inclusion criteria. Their mean age was 50.1 years (range 21-89). The most frequent symptoms were abdominal pain, vomiting and fever. More than half the patients (16/30) had underlying conditions associated with immunosuppression including diabetes mellitus and tuberculosis. Pathological investigation of colonic resections showed predominantly right-sided involvement with geographic colonic ulcers covered with a creamy-white pseudomembrane, perforations, gangrenous changes, amoeboma and lesions mimicking inflammatory bowel disease. All showed basophilic dirty necrosis with abundant nuclear debris and amoebic trophozoites on histological examination. 21/30 patients (70%) had involvement beyond the caecum. 17/30 patients (57%) died. Those with involvement beyond the caecum were more likely to die (15/21, 71.4%) than those with less extensive disease.

CONCLUSIONS

FAC presents as acute abdomen and can mimic appendicitis, ischaemic bowel disease, tuberculosis and malignancy. Comorbidities causing immunosuppression frequently associated. Mortality remains high despite surgery, so FAC should be suspected in every case of acute abdomen with colonic perforation if associated with typical gross and microscopic findings and a history of stay in an endemic area.

Presence and diagnosis of amebic infestation in Turkish patients with active ulcerative colitis

BACKGROUND

It is difficult to definitively diagnose acute amebiasis, particularly when this condition is superimposed on inflammatory bowel disease. Our goals in this study were to determine the prevalence of amebiasis in individuals with active ulcerative colitis, and to identify clinical and laboratory parameters that are of value for diagnosing amebiasis in this patient group.

METHODS

The subjects were 111 patients (76 women, 35 men) with confirmed active ulcerative colitis who attended our hospital's Inflammatory Bowel Disease Outpatient Clinic between May 2002 and March 2006. In each case, a detailed medical history was collected, blood samples were tested for inflammatory markers, and stool samples were evaluated for presence of amebae using an Enzyme-Linked Immunosorbent Assay (ELISA) for detection of Entamoeba histolytica antigen. The clinical and laboratory variables for the ELISA-positive and ELISA-negative groups were compared.

RESULTS

Amebiasis was detected in 35 (31.5%) of the subjects. Patient age, disease duration, endoscopic activity index, serum C-reactive protein level, and white blood cell count were not useful for diagnosing amebiasis in this patient group.

CONCLUSIONS

Given the high rate of amebiasis observed in our patients with active ulcerative colitis, we recommend that, in Turkey any individual with ulcerative colitis who presents with symptoms of disease activation should be tested for ameba using antigen detection kits. A high index of suspicion is especially important in any region where E. histolytica is endemic.

Expression of immune modulator cytokines in human fulminant amoebic colitis

Human fulminant amoebic colitis (FAC) is characterized by ulceration and inflammation of the colon. The specific mixture of pro-inflammatory and anti-inflammatory cytokines may participate in either the host defense or in the pathogenesis of amoebic colitis. Therefore, we studied the expression of IL-8, IL-10, IL-4, TGF-beta and IFN-gamma in human FAC patients and controls through immunohistochemistry analysis. The number of cells expressing IL-8, IL-4 and IL-10 was significantly enhanced in all FAC samples compared to the control samples. However, the expression of TGF- beta in patients was low in the colonic mucosa and high in the lamina propria compared with the control. No expression of IFN-gamma was found in the controls or FAC samples. The production of IL-8 by intestinal epithelial cells may play a role in the pathogenesis of amoebic infection, because this cytokine attracts neutrophils, which lead to an inflammatory reaction that results in tissue damage. The predominant expression of the macrophage down-regulating cytokines, IL-4, IL-10 and TGF-beta, or the Th2-type immune response could inhibit a cell-mediated immune response, which in turn would facilitate parasite invasion in these tissues.

Parasitic infections of the gastrointestinal tract

This article updates recent advances in the body of knowledge of diagnosis and treatment of intestinal parasites. The articles focus on the manifestations of disease in the immunocompetent adult host from developed countries. Specific pathogens discussed are Giardia lamblia and Dientamoeba fragilis, Entamoeba histolytica, Entamoeba dipar, Blastocystis hominis, Cyclospora cayetanensis, and Cryptosporidium parvum.

Colonic perforation in unsuspected amebic colitis

Unsuspected amebic colitis presenting as inflammatory bowel disease, as in our patient, has been previously reported (4, 7, 8). Misdiagnosis, delay in antibiotic treatment, and institution of immunosuppression were the result of failure to identify the parasite in stool specimens and have resulted in suffering, morbidity, mortality, and surgery. In all previously reported cases, routine stool studies failed to identify E. histolytica (4, 7, 8). The correct diagnosis was only established after reviewing the surgical specimen or biopsies obtained endoscopically. Because the erroneous diagnosis of inflammatory bowel disease can lead to disastrous complications, it is imperative to exclude amebic colitis prior to undertaking steroid therapy, especially in patients with a prior history of travel to or residence in areas with endemic E. histolytica (17). We recommend obtaining at least three stool specimens for microscopic examination, as well as testing for serum amebic antibody. Patients should submit fresh stool specimens directly to the laboratory to allow for prompt diagnostic evaluation. Such an approach might lead to the improved diagnosis of amebiasis.

Fulminant amebic colitis: analysis of 55 cases

Fulminant amebic colitis is a rare disease with high morbidity and mortality.

PURPOSE

This study was designed to identify the most frequent clinical and histopathologic features of fulminant amebic colitis and to analyze results of surgical treatment and the existence of risk factors for mortality.

MATERIALS AND METHODS

A retrospective analysis was conducted of clinical and histopathologic data of 55 patients with fulminant amebic colitis. Data were obtained from the files of autopsies and surgical operations that had been performed at a referral center in Mexico from 1943 through 1994.

RESULTS

Median age was 52 (range, 18-79) years. There were 34 men (62 percent) and 21 women (38 percent). Diabetes mellitus and chronic alcoholism were the most frequent diseases in association with fulminant amebic colitis (40 and 31 percent, respectively). The most frequent clinical manifestations were abdominal pain, diarrhea, rectal bleeding, and fever. There was a coexistent amebic liver abscess in 54 percent of patients. The main histopathologic characteristics were necrosis, presence of trophozoites, and acute and/or chronic inflammation. Of 25 patients who underwent surgery, only six survived (operative mortality, 76 percent; overall mortality, 89 percent). The variables that correlated with mortality were longer duration of symptoms, lower count of leukocytes, nonsurgical treatment, nonresective surgical procedure, hospital admission before 1971, and invasion of trophozoites into or through the muscularis.

CONCLUSIONS

The results may help to obtain an earlier diagnosis and establish proper treatment of fulminant amebic colitis.

Fatal amoebic colitis in a patient with SLE: a case report and review of the literature

Colitis in systemic lupus erythematosus (SLE) poses a diagnostic challenge as clinical, radiological and laboratory findings are often non-specific. Fulminant amoebic colitis is a rare cause of death in SLE. Early diagnosis coupled with timely surgery can reduce the mortality. The demonstration of haematophagous trophozoites in the stool is diagnostic but insensitive. Early endoscopy with adequate specimen collection is an important part of the diagnosis. Serology is both sensitive and specific but can take up to 2-4 weeks for seroconversion making it less useful in a disease that takes a rapid downhill course if treated inappropriately. We report a fatal case of colitis in a patient with SLE due to invasive amoebiasis which was complicated by Salmonella bacteraemia, disseminated intravascular coagulation, acute oliguric renal failure and adult respiratory syndrome. We also reviewed the literature on the clinical features and diagnosis of fulminant amoebic colitis. Amoebic colitis, although rare, should be considered in the differential diagnosis of lupus patients with colitis.

Diarrheal diseases associated with HIV infection

Diarrhea is a major complication of HIV infection and adversely impacts health care costs, quality of life, and even survival of patients. There is a wide variety of potential causes of diarrhea in HIV-infected patients, and the number of pathogens found continues to increase with time. In addition, there is some controversy concerning the role of some organisms in the pathogenesis of diarrhea and the appropriate diagnostic evaluation of affected patients. This article reviews our current understanding of these pathogens and some of the diagnostic and therapeutic approaches for diarrhea associated with HIV infection.

Protozoa. Amebiasis

The intestinal protozoan parasite Entamoeba histolytica causes amebic dysentery and amebic liver abscess, and ranks third worldwide among parasitic causes of death. The application of molecular techniques to the study of this organism have led to major advances in understanding the pathophysiology of amebic infection. This article reviews what is currently known about the pathogenesis, clinical manifestations, diagnosis, and treatment of amebiasis.

Recent advances in amebiasis

Advancements in our understanding of amebiasis have been rapid over the decade that I have followed this field. What was identified morphologically for years as Entamoeba histolytica has been redescribed with modern techniques as a complex of two species, the commensal parasite E. dispar and the pathogenic parasite E. histolytica that is the cause of colitis and liver abscess. Antigen detection tests are now available for the rapid detection in stool of the pathogenic species E. histolytica. New understandings of the importance of luminal as well as tissue-active antimebic medications in the treatment of invasive disease have been reached. The groundwork is being laid for an understanding of the protective immune responses to infection, and at the lab bench DNA transfection of the parasite has opened studies of pathogenesis to genetic analysis. While necessarily an incomplete sketch of the field, I have attempted here to highlight some recent and important developments of interest to clinicians and microbiologists.