Abdominal angiostrongyliasis, report of two cases and analysis of published reports from Colombia. / Abdominal angiostrongyliasis, report of two cases and analysis of published reports from Colombia

Abdominal angiostrongyliasis is a parasitic zoonosis, endemic in the American continent. Its etiological agent is Angiostrongylus costaricensis, a nematode whose definitive hosts are rats and other rodents and the intermediate hosts, slugs. Mammals acquire the infection by consuming vegetables contaminated with L3 larvae. The disease shows a heterogeneous clinical spectrum and given its low incidence its diagnosis is a great challenge. In Colombia, the first case was reported in 1979 and until 1998, only five additional cases have been reported. However, in the last two decades, no new cases were reported. Here we discuss two cases of children from Huila and Caquetá departments who developed the disease. Both cases required long in-patient care and multiple surgical interventions. The diagnosis was achieved by histopathological observation of parasitic elements inside the mesenteric arteries. One of the children died while the other fully recovered. We discuss the epidemiology, pathogenic cycle, clinical presentation, diagnosis, and prevention strategies of this disease paying particular attention to our patients' features and the Colombian context.

La angiostrongiloidiasis abdominal es una zoonosis parasitaria endémica en el continente americano. Su agente etiológico es el nematodo Angiostrongylus costaricensis, cuyos huéspedes definitivos son los roedores y, los intermediarios, los caracoles y las babosas, por lo que se adquiere al consumir vegetales contaminados con larvas en estadio 3. La presentación clínica es muy variada y, dada su rareza, su diagnóstico es un desafío. En Colombia el primer caso se reportó en 1979 y, desde entonces hasta 1998, se han informado cinco casos más, aunque en las últimas dos décadas no se había reportado ningún caso. Se describen aquí dos casos de angiostrongiloidiasis en niños provenientes de los departamentos de Huila y Caquetá que requirieron una larga hospitalización y múltiples intervenciones quirúrgicas. El diagnóstico se logró al observar en los especímenes quirúrgicos larvas and huevos cuya morfología sugería una infección por nematodos; uno de los pacientes murió y el otro se recuperó satisfactoriamente. Se discuten la epidemiología, la patogenia, la presentación clínica, el diagnóstico y las estrategias de prevención de esta parasitosis, con énfasis en las características particulares de los casos descritos y en el contexto colombiano.

Changes in the severity of gastric mucosal inflammation associated with Helicobacter pylori in humans coinfected with intestinal helminths.

BACKGROUND: Though a few studies in animal models suggest that intestinal helminths (IH) favorably affect evolution of gastritis associated with Helicobacter pylori (H. pylori) the studies supporting this concept in humans are only a few and are based on serological data. METHODS: To evaluate the possible influence of IH on the human gastric mucosa, three groups of Venezuelan adults with gastropathy (endoscopically diagnosed) were studied: H. pylori-/IH- (n = 17), H. pylori+/IH- (n = 18), and H. pylori+/IH+ (n = 11). Histological analysis (hematoxylin-eosin) and immunohistochemical staining (peroxidase) for cytokines interleukin-1beta (IL-1ß), tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), and interleukin 4 (IL-4) were undertaken in gastric antral biopsies. RESULTS: Expression of the four cytokines was detected in all individuals in varying degrees, but proinflammatory cytokines were expressed in a higher degree in the H. pylori+/IH- group, mainly IL-1ß (Th1-dominant immune response), associated with a higher degree of both histological inflammation and gastric cancer risk index (GCRI), as compared to the H. pylori-/IH- group. In contrast, an increased expression of IL-4 and a reduced expression of proinflammatory cytokines (Th2-dominant response), plus the tendency to a lower degree of mononuclear infiltration, mucosal atrophy in gastric corpus, and GCRI, were evidenced in the coinfected group. CONCLUSIONS: The findings of the present study is perhaps the first histological evidence of a possible modulatory effect of IH on the gastric mucosal inflammatory response due to H. pylori infection in humans.

Disease, drugs, or dinner? Food histology can mimic drugs and parasites in the gastrointestinal tract.

Microscopic foreign objects are sometimes found in gastrointestinal (GI) tract specimens. Some signify important diagnostic findings, such as parasitic or bacterial organisms and some medication resins. Partially digested fruits and vegetables can also be present, and some have been described in the literature as potential mimickers of clinically important findings. While animal protein appears as skeletal muscle on histologic examination, fruits and vegetables can show a wide variation under the microscope. To our knowledge, a thorough histologic examination of commonly eaten fruits and vegetables has not been published in the pathology literature. Herein, we present key morphologic features of fruits and vegetables that might be found in GI specimens, emphasizing potential mimics of significant pathologic findings.

Differential Expression of Soluble Receptor for Advanced Glycation End-products in Mice Susceptible or Resistant to Chronic Colitis.

BACKGROUND: Identifying the factors that contribute to chronicity in inflamed colitic tissue is not trivial. However, in mouse models of colitis, we can investigate at preclinical timepoints. We sought to validate murine Trichuris muris infection as a model for identification of factors that promote development of chronic colitis. METHODS: We compared preclinical changes in mice with a resolving immune response to T. muris (resistant) vs mice that fail to expel the worms and develop chronic colitis (susceptible). Findings were then validated in healthy controls and patients with suspected or confirmed IBD. RESULTS: The receptor for advanced glycation end products (RAGE) was highly dysregulated between resistant and susceptible mice before the onset of any pathological signs. Increased soluble RAGE (sRAGE) in the serum and feces of resistant mice correlated with reduced colitis scores. Mouse model findings were validated in a preliminary clinical study: fecal sRAGE was differentially expressed in patients with active IBD compared with IBD in remission, patients with IBD excluded, or healthy controls. CONCLUSIONS: Preclinical changes in mouse models can identify early pathways in the development of chronic inflammation that human studies cannot. We identified the decoy receptor sRAGE as a potential mechanism for protection against chronic inflammation in colitis in mice and humans. We propose that the RAGE pathway is clinically relevant in the onset of chronic colitis and that further study of sRAGE in IBD may provide a novel diagnostic and therapeutic target.

Infections and pathology of free-roaming backyard chickens on St. Kitts, West Indies.

Free-roaming chickens on Caribbean islands are important sentinels for local avian diseases and those introduced by birds migrating through the Americas. We studied 81 apparently healthy unvaccinated free-roaming chickens from 9 parishes on St. Kitts, an eastern Caribbean island. Using commercial ELISAs, no chickens had antibodies against avian influenza virus, West Nile virus, or Salmonella Enteritidis, although seropositivity was high to infectious bursal disease virus (86%), infectious bronchitis virus (84%), Mycoplasma (37%), and avian avulavirus 1 (Newcastle disease virus, 31%). Examination of small and large intestinal contents revealed cestodes in 79% and nematodes in 75% of the chickens. Although ectoparasites and endoparasites were common (74% and 79%, respectively), only a few chickens had lesions at postmortem examination, mainly intestinal serosal nodules (12%) and feather loss (6%). Histologic examination of 18 organs from each bird revealed lesions in high percentages of organs, mainly the liver (86%), lung (75%), spleen (60%), small intestine (56%), skin (42%), and kidney (40%). Lesions included degenerative, reactive, inflammatory, and neoplastic, and were not correlated with the serologic status of the chickens except in one case of infectious bursal disease. Microscopically, Paratanaisia bragai was seen in the kidneys of 3 chickens and intestinal coccidiasis in 1 chicken. Pulmonary silicate aggregates were common, were present in intestinal serosal nodules, and were suggestive of environmental exposure.

Dipylidium caninum Infection in Children: Clinical Presentation and Therapeutic Challenges.

Dipilidium caninum infection is a relatively uncommon parasitic infection in children. We present 10 cases treated in our tertiary care hospital during the last 2 years. This parasitosis has a relatively benign course but should be considered in children with gastrointestinal symptoms and eosinophilia. Treatment can be challenging, especially in infancy. Preventative measures are necessary to avoid the spread of the disease.

Effect of selected gastrointestinal parasites and viral agents on fecal S100A12 concentrations in puppies as a potential comparative model.

BACKGROUND: Previous data suggest that fecal S100A12 has clinical utility as a biomarker of chronic gastrointestinal inflammation (idiopathic inflammatory bowel disease) in both people and dogs, but the effect of gastrointestinal pathogens on fecal S100A12 concentrations is largely unknown. The role of S100A12 in parasite and viral infections is also difficult to study in traditional animal models due to the lack of S100A12 expression in rodents. Thus, the aim of this study was to evaluate fecal S100A12 concentrations in a cohort of puppies with intestinal parasites (Cystoisospora spp., Toxocara canis, Giardia sp.) and viral agents that are frequently encountered and known to cause gastrointestinal signs in dogs (coronavirus, parvovirus) as a comparative model. METHODS: Spot fecal samples were collected from 307 puppies [median age (range): 7 (4-13) weeks; 29 different breeds] in French breeding kennels, and fecal scores (semiquantitative system; scores 1-13) were assigned. Fecal samples were tested for Cystoisospora spp. (C. canis and C. ohioensis), Toxocara canis, Giardia sp., as well as canine coronavirus (CCV) and parvovirus (CPV). S100A12 concentrations were measured in all fecal samples using an in-house radioimmunoassay. Statistical analyses were performed using non-parametric 2-group or multiple-group comparisons, non-parametric correlation analysis, association testing between nominal variables, and construction of a multivariate mixed model. RESULTS: Fecal S100A12 concentrations ranged from < 24-14,363 ng/g. Univariate analysis only showed increased fecal S100A12 concentrations in dogs shedding Cystoisospora spp. (P = 0.0384) and in dogs infected with parvovirus (P = 0.0277), whereas dogs infected with coronavirus had decreased fecal S100A12 concentrations (P = 0.0345). However, shedding of any single enteropathogen did not affect fecal S100A12 concentrations in multivariate analysis (all P > 0.05) in this study. Only fecal score and breed size had an effect on fecal S100A12 concentrations in multivariate analysis (P < 0.0001). CONCLUSIONS: An infection with any single enteropathogen tested in this study is unlikely to alter fecal S100A12 concentrations, and these preliminary data are important for further studies evaluating fecal S100A12 concentrations in dogs or when using fecal S100A12 concentrations as a biomarker in patients with chronic idiopathic gastrointestinal inflammation.

Intestinal parasites from the 2nd-5th century AD latrine in the Roman Baths at Sagalassos (Turkey).

The aim of this research was to determine the species of intestinal parasite present in a Roman Imperial period population in Asia Minor, and to use this information to improve our understanding of health in the eastern Mediterranean region in Roman times. We analyzed five samples from the latrines of the Roman bath complex at Sagalassos, Turkey. Fecal biomarker analysis using 5ß-stanols has indicated the feces were of human origin. The eggs of roundworm (Ascaris) were identified in all five samples using microscopy, and the cysts of the protozoan Giardia duodenalis (which causes dysentery) were identified multiple times in one sample using ELISA. The positive G. duodenalis result at Sagalassos is particularly important as it represents the earliest reliable evidence for this parasite in the Old World (i.e. outside the Americas). As both these species of parasite are spread through the contamination of food and water by fecal material, their presence implies that Roman sanitation technologies such as latrines and public baths did not break the cycle of reinfection in this population. We then discuss the evidence for roundworm in the writings of the Roman physician Galen, who came from Pergamon, another town in western Asia Minor.

Multiple parasitic and viral infections in a patient living with HIV/AIDS on antiretroviral therapy.

Patients with human immunodeficiency virus (HIV) infection are more prone for gastrointestinal infections causing diarrhoea, particularly with parasites. Parasitic infections have been regularly reported in such patients. A female patient confirmed positive for HIV 1 on antiretroviral therapy came with complaints of chronic diarrhoea for the past 7 months. Her initial CD4 count was 89 cells/µl of blood, and antibodies to cytomegalovirus and herpes simplex virus 1 and 2 virus were found to be positive in the patient's serum, but there was no HIV-associated retinopathy. Her stool examination showed decorticated fertilised eggs of Ascaris lumbricoides, cysts of Blastocystis sp. and Entamoeba species in the unconcentrated sample and oocysts of Cystoisospora species, egg of Schistosoma haematobium and eggs of Trichuris trichiura in the concentrated. The patient responded well to cotrimoxazole and albendazole, and repeat samples were negative for all these parasites.

Morphological and histochemical changes associated with massive infection by Neoechinorhynchus buttnerae (Acanthocephala: Neoechinorhynchidae) in the farmed freshwater fish Colossoma macropomum Cuvier, 1818 from the Amazon State, Brazil.

The study describes the morphological changes associated with parasitism by the intestinal acanthocephalan Neoechinorhynchus buttnerae in tambaqui juveniles Colossoma macropomum farmed in an excavated nursery, in Manaus (Amazon) in September 2013. After fish biometrics, analysis of macroscopic changes in morphology and counting of parasites, bowel fragments were fixed and submitted to histological and histochemical processing. All fish analyzed had acanthocephalans in the intestine; intestinal loops were milky white in color, with the presence of nodules with heavy parasitism. The changes in tissues that form the intestine varied according to the arrangement of the parasites: either free in the intestinal lumen or fixed by the proboscis on the organ wall. In the first case, the changes found were flaking, abrasion, compression, hypertrophy of goblet cells and disappearance of the villi on the mucosa, leukocytic cell infiltration in the submucosa, and muscle layer thickening. In the second case, in addition to these, other changes were observed as metaplasia in muscle tissue with its replacement by a loose connective tissue with severe leukocytic infiltration, edema in blood vessels, and necrotic foci. The histochemical analysis revealed that positive Alcian Blue mucosal cells (pH 2.5) were more expressive in parasitized intestines than in intestines not parasitized by N. buttnerae.

HISTOPATHOLOGICAL ANALYSIS OF SCHISTOSOMIASIS IN THE GASTROINTESTINAL TRACT WITH FIRST RECORD OF SCHISTOSOMAL APPENDICITIS FROM SOHAG, UPPER EGYPT.

Schistosomiasis is a chronic granulomatous inflammation that affects many systems in the body including the gastrointestinal tract. Appendiceal schistosomiasis is also described and can be a precursor lesion of schistosomal appendicitis. The present study was done to make a retrospective analysis of histopathological changes in the gastrointestinal tract affected by Sckistosoma mansoni among patients attending Sohag University Hospital, Sohag Governorate between June 2013 and June 2016. A total of 150 colon and 30 appendix specimens were collected through out the period from male infected pa- tients aged between 35-50 years and suffering from abdominal pain and dysentery. Histopathological examination of the tissue biopsies was performed. 5p tissue sections were prepared and examined microscopically. Ten specimens were documented to have intestinal schistosomiasis, nine of the colon 9/150 (6%) were diagnosed as chronic schistosomal colitis and one of the appendix 1/30 (3.3%) as chronic schistosomal appendicitis. Microphotographs of the tissue sections were prepared for histopathological observations. Histopathological examination of all specimens revealed degenerated pinkish and calcified bluish bilharzial eggs in the submucosa and even musculosa with surrounding granulomatous reaction. Bilharzial polyps of the colon were detected in two specimens (20%) and bilharzial worms within venules of the muscle layer in two specimens (20%). During the present study, S. mansoni was documented as a not uncommon cause of chronic colitis and for the first time from Sohag as a cause of chronic appendicitis. All specimens did not show any malignant or premalignant cells.

Unexpected findings in the routine histopathological examinations of appendectomy specimens A retrospective analysis of 1,970 patients.

INTRODUCTION: Diseases and tumors of the appendix vermiformis are very rare, except for acute appendicitis. This study aimed to examine rare findings in the histopathologic examinations of specimens of patients undergoing appendectomy due to the diagnosis of acute appendicitis. METHODS: The files of 1,970 patients undergoing appendectomy due to the diagnosis of acute appendicitis between March 2012 and March 2016 were retrospectively investigated. Rare findings were found in 59 (3%) patients, and these were evaluated in detail. Patients' age, gender, pathology reports, and post-operation follow-ups were recorded. RESULTS: The rare histopathological findings of 59 patients were examined. Of these, 31 were female (52.5%) and 28 were male (47.5%). The average age was 33.1±18.2 years. The unusual findings were as follows: 16 Fibrous obliteration, 11 Enterobius vermicularis, 2 Schistosomiasis, 3 Appendiceal neuroma, 2 Granulomatous appendicitis, 1 Crohn's disease, 3 Chronic appendicitis, 1 Endometriosis, 2 Hyperplastic polyps, 9 Mucinous cystadenoma (+mucocele), 8 Carcinoid tumors and 1 Lymphoma. All of the malignant tumors were localized in the distal end of the appendix and all of the patients were treated with appendectomy. Patients with parasitic diseases also underwent anthelmintic treatment, while chemotherapy was administered to the patient with lymphoma. All of the patients diagnosed with malignancy were alive reported no problems at their follow-ups. CONCLUSION: Although all of the appendectomy samples were normal macroscopically, data from this study suggest that all specimens should be sent for routine investigation. KEY WORDS: Appendicitis, Appendectomy, Carcinoid, Mucocele, Endometriosis.

Gastrointestinal Parasitosis: Histopathological Insights to Rare but Intriguing Lesions of the Gastrointestinal Tract.

OBJECTIVE: Gastrointestinal parasitosis is a significant cause of morbidity and mortality. Definitive diagnosis is usually made by stool tests and/or serology but may require tissue evaluation. Although pathologists are usually familiar with common parasites, it is not well established whether the diagnosis could be suspected without seeing the "parasite" itself. MATERIAL AND METHOD: Resection or biopsy specimens of 32 cases with Giardia intestinalis (n=20), Enterobius vermicularis (n=5), Entamoeba histolytica (n=4), Fasciola hepatica (n=1), Strongyloides spp. (n=1) and Taenia saginata (n=1) infections were retrospectively re-evaluated for accompanying mucosal changes, and compared with nonparametric tests. RESULTS: The most common changes were congestion (65.6%) and eosinophilic infiltration (50%). Chronic active mucosal inflammation accompanied 37.5% of the cases. More than 10 eosinophils/HPF were present in 43.8%. Only one case of G. intestinalis, E. vermicularis, E. histolytica, and F. hepatica showed more than 50 eosinophils/HPF. Mucosal architectural abnormalities were present in 34.4%. Granulomas, giant cells and Charcot-Leyden crystals were only seen accompanying F. hepatica. No statistically significant difference was found between parasite subspecies regarding presence of inflammation, lymphoid aggregates, architectural distortion, congestion, ulceration and increase of eosinophils. CONCLUSION: Parasites induce nonspecific inflammation, slight mucosal architectural changes, mild eosinophilic infiltrate or granuloma formation. They may cause ulceration, bowel obstruction or perforation. Parasitosis should also be considered when evaluating cases mimicking inflammatory bowel disease, celiac disease or those that do not fulfill diagnostic criteria.

Dientamoeba fragilis, One of the Neglected Intestinal Protozoa.

Dientamoeba fragilis is a single-celled protozoan, closely related to the trichomonads. Reported worldwide as causing human gastrointestinal symptoms, D. fragilis is very common and is second only to Blastocystis spp. Dientamoebiasis equals or exceeds the incidence of giardiasis. This minireview includes diagnostic options, clinical relevance, therapy, an animal model, the confirmed cyst stage, and sequencing data. The development of a rodent model, fulfilling Koch's postulates, and the confirmation of a cyst stage have clarified transmission routes, including fecal-oral transmission. The prevalence of D. fragilis varies between 0% to over 82%; results depend on the geographic location, group studied, and diagnostic methods used.

Correlation study and histopathological description of intestinal alterations in dogs infected with Leishmania infantum / Estudo de correlação e descrição histopatológica das lesões intestinais de cães infectados com Leishmania infantum

Abstract The aim of this work was a correlation study and histopathological description of alterations associated with the presence of Leishmania infantumamastigote in the intestinal wall of dogs infected with canine visceral leishmaniasis (CVL). Three groups were used: G1 (n = 8), comprising naturally infected dogs with CVL with amastigotes of L. infantum in the small and large intestines; G2 (n = 9), infected dogs with CVL, without intestinal amastigotes; and G3 (n = 3), uninfected dogs. Histochemistry and immunohistochemistry methods were used for histopathology and amastigotes identification. 47.1% (8/17) of dogs from G1 group had amastigotes in the mucosa, submucosa and muscle layers of the small and large intestines and it was observed a prominent inflammatory reaction characterized by chronic infiltration of mononuclear cells: macrophages, lymphocytes and plasma cells. Comparison between the groups showed only a significant difference in relation to mucosal microscopic structural alterations in dogs from G1 in relation to G2 and G3. Parasite burden showed significant correlations with the microscopic alterations and clinical status of dogs in G1. By the conclusion, the inflammatory reactions caused by the parasites in the intestines might have contributed towards alterations in digestive processes, worsening the dogs’ clinical status of CVL.

Resumo O objetivo foi realizar um estudo de correlação e descrição histopatológica das lesões associadas à presença de amastigotas de Leishmania infantum na parede intestinal de cães infectados com leishmaniose visceral canina (LVC). Os cães foram subdivididos em três grupos: G1 (n = 8) cães naturalmente infectados com LVC e com amastigotas de L. infantum no intestino; G2 (n = 9) com LVC, mas sem o parasitismo intestinal; e G3 (n = 3) cães não infectados. Métodos histoquímicos e imunoistoquímicos foram utilizados para a histopatologia e a identificação das amastigotas, respectivamente. 47,1% (8/17) dos cães infectados (grupo G1) apresentavam formas amastigotas na mucosa, submucosa e camada muscular do intestino delgado e grosso, destacando-se uma reação inflamatória caracterizada por infiltrado crônico de células mononucleares; macrófagos, linfócitos e plasmócitos. Observou-se uma diferença significativa somente com relação às alterações estruturais microscópicas intestinais nos cães do G1 quando comparadas com G2 e G3. A intensidade parasitária intestinal teve correlação significativa com as alterações microscópicas e os sinais clínicos dos cães do G1. Concluiu-se que as amastigotas de L. infantum por causarem reações inflamatórias na parede intestinal dos cães podem ter contribuído para as alterações dos processos digestórios, agravando ainda mais o quadro clínico dos animais.

Prevalence of Schistosomes and Soil-Transmitted Helminths and Morbidity Associated with Schistosomiasis among Adult Population in Lake Victoria Basin, Tanzania.

The objective of this study was to carry out a community survey on schistosomiais and soil-transmitted helminth (STH) infections in order to suggest feasible and effective intervention strategies in Lake Victoria basin, Tanzania. A total of 37 communities selected from 23 districts of the 4 regions in the Lake Victoria basin of Tanzania were involved in the study. From each of the selected locality, 50 adult community members, 25 males and 25 females, were recruited for the study. Each study participant was requested to submit stool and urine specimens. From each stool specimen, duplicate Kato-Katz thick smears were prepared and microscopically examined for Schistosoma mansoni and STH eggs. Urine specimens were processed by the filtration technique and microscopically examined for Schistosoma haematobium eggs. Ultrasound examination for morbidity due to schistosomiasis was performed. Mass treatment was done using praziquantel and albendazole for schistosome and STHs infections, respectively. Out of 1,606 adults who provided stool specimens, 199 (12.4%) were positive for S. mansoni, 349 (21.7%) for hookworms, 133 (8.3%) for Ascaris lumbricoides, and 33 (2.0%) for Trichuris trichiura. Out of 1,400 participants who provided urine specimens, 25 (1.8%) were positive for S. haematobium eggs. Because of the co-endemicity of these afflictions and their impact on vulnerable population groups, the helminthiasis could be simultaneously treated with 2 drugs, praziquantel for schistosomiasis and albendazole for STHs.

Pathological and parasitological characterization of infection by trematodes (Paramphistomatidae) in the large intestine of capybaras / Caracterização patológica e parasitológica da infecção por trematódeos (Paramphistomatidae) no intestino grosso de capivaras

Gross and histological lesions caused by an intestinal parasite were described in three capybaras. The parasites presented a mean length of 14 mm and width of 7 mm, were round to oval or piriform, reddish and pedunculated, and adhered strongly to the mucosa of the large intestine. The intestinal mucosa at the parasite attachment site presented loss of surface epithelium and most glands, with replacement by fibrovascular proliferation that protruded from the mucosa and was involuted by the ventral sucker of the parasite. The lamina propria presented cellular debris, eosinophils, macrophages and plasma cells. The morphological characteristics, observed using serial histological sections, made it possible to classify the parasite as a trematode (Paramphistomatidae), compatible with Taxorchis schistocotyle. One capybara also harbored many ciliated protozoa in the large intestine (at the site of attachment of the parasite) and inside the caeca of the trematodes. In conclusion, this study described a multifocal necrotizing colitis associated with T. schistocotyle parasitism in capybaras.

Lesões macroscópicas e histológicas causadas por um parasita intestinal foram descritas em três capivaras. Os parasitas apresentaram média de 14 mm de comprimento e 7 mm de largura, eram de circulares a ovais ou piriformes, avermelhados, pedunculados e estavam fortemente aderidos à mucosa do intestino grosso. A mucosa intestinal, em que os parasitas estavam aderidos, apresentou perda do epitélio e da maioria das glândulas, sendo substituídos por proliferação fibrovascular que se projetava a partir da mucosa e era envolvida pela ventosa ventral do parasita. A lâmina própria apresentou restos celulares, eosinófilos, macrófagos e plasmócitos. As características morfológicas, utilizando cortes histológicos seriados, proporcionaram a classificação do parasita como um trematoda Paramphistomatidae, compatível com Taxorchis schistocotyle. Uma capivara continha também numerosos protozoários ciliados no intestino grosso (no local de fixação do parasita) e no lúmen do ceco desses parasitos. Em síntese, este estudo demonstrou a ocorrência de colite necrótica associada ao parasitismo por T. schistocotyle em capivaras.