Fatal parasite-induced enteritis and typhlocolitis in horses in Southern Brazil / Enterites e tiflocolites parasitárias fatais em equinos no Sul do Brasil

Abstract Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri enteritis (1/10), B. coli colitis related to cyathostominae (1/10), and infection by multiple agents (1/10). Cyathostominae typhlocolitis showed marked mucosal thickening, with multifocal elevated nodules containing tangled filiform parasites. Microscopic examination revealed that the mucosa and submucosa had encysted parasitic structures surrounded by eosinophilic and granulomatous inflammation. E. leuckarti enteritis was microscopically characterized by macrogamonts, microgamonts, and oocysts inside the host cells. S. westeri enteritis showed microscopic atrophy of the villi with numerous mucosal encysted parasitic structures. B. coli typhlocolitis showed severe diffuse mucosal reddening, with microscopic superficial mucosal necrosis associated with multiple protozoan trophozoites. Fatal parasite-induced enteritis and typhlocolitis are important causes of death in horses in Southern Brazil.

Resumo Doenças relacionadas ao sistema alimentar são as principais causas de morte em equinos. Esse estudo teve o objetivo de descrever aspectos patológicos de enterites e tiflocolites parasitárias fatais por ciatostomíneos, Eimeria leuckarti, Balantidium coli e Strongyloides westeri, em equinos. Foi revisado o banco de dados de lesões intestinais parasitárias em equinos necropsiados de 2005 a 2017, no Sul do Brasil. Dez equinos apresentaram enterite e/ou tiflocolite parasitária fatal, e as principais foram: tiflocolite por ciatostomíneos (6/10), enterite por E. leuckarti (1/10), enterite por S. westeri (1/10), colite por B. coli com ciatostomíneos (1/10), e infecção por múltiplos agentes (1/10). A tiflocolite por ciatostomíneos exibia acentuado espessamento da mucosa, com nódulos multifocais elevados contendo parasitas filiformes. Microscopicamente, a mucosa e submucosa apresentavam estruturas parasitárias encistadas envoltas por inflamação eosinofílica e granulomatosa. A enterite por E. leuckarti era caracterizada microscopicamente por macrogamontes, microgamontes e oocistos no interior de células do hospedeiro. Microscopicamente, a enterite por S. westeri apresentava atrofia de vilosidades com numerosas estruturas parasitárias encistadas na mucosa. A tiflocolite por B. coli exibia avermelhamento acentuado difuso da mucosa, e microscopicamente necrose superficial associada a múltiplos trofozoítos protozoáricos. Enterites e tiflocolites fatais parasitárias são importantes causas de morte em equinos no Sul do Brasil.

Eficacia del tinidazol en la profilaxis terapéutica de la colitis amebiana en pacientes con leucemia aguda de novo que reciben quimioterapia intensiva / Efficacy of tinidazole in the therapeutic prophylaxis of amoebic colitis in patients with de novo acute leukemia receiving intensive chemotherapy

Resumen Introducción: En México la seroprevalencia de la Entamoeba histolytica es del 8.4%. La amebiasis intestinal en pacientes con leucemia aguda de novo posterior al inicio de quimioterapia (QT), en el Servicio de Hematología del CMN 20 de Noviembre, es del 12%, aún si muestran test coprológico negativo basal. Objetivo: Averiguar si la administración de tinidazol, en pacientes con leucemia aguda y coprológico negativo, al principio de la QT, disminuye la incidencia de colitis amebiana durante la inducción a la remisión. Método: Prospectivo y no comparativo. Enfermos con diagnóstico de leucemia aguda de novo que inician QT de inducción y coprológico inicial. Se indicó tinidazol, 2 g/día durante 5 días en la primera semana de comenzada QT. Se vigilaron hasta que la inducción concluyó y se inició la recuperación hematopoyética. Resultados: 38 pacientes, 15 mujeres y 23 hombres con edad media de 44 años (16-72). Con leucemia aguda linfoblástica 19, con mieloblástica 16 y con promielocítica 3. Casos sin y con amebiasis intestinal, 35 y 3, respectivamente. Los pacientes con amebiasis solo recibieron tinidazol durante 3 días y se dio después de 2 días de empezada la QT. Conclusión: El tinidazol, en pacientes con leucemia aguda de novo que inician QT de inducción, es efectivo en la prevención de la amebiasis intestinal, durante la etapa de inducción, si se administra a 2 g/día, durante cinco días, a partir del día 1 de la QT.

Abstract Introduction: In Mexico, seroprevalence of Entamoeba histolytica is 8.4%. The intestinal amebiasis in patients with acute leukemia of novo, after the start of chemotherapy (CT) in the Hematology Service of the CMN 20 de Noviembre is 12%, even if patients show a negative baseline coprological test. Objective: To find out if the administration of tinidazole, in patients with acute leukemia and negative coprological test, at the beginning of the CT, decreases the incidence of amoebic colitis during the induction to remission. Method: Prospective and not comparative study. Patients with de novo diagnosis of acute leukemia who initiate induction and initial coprological CT. Tinidazole was indicated, 2 g/day for 5 days in the first week of CT started. They were monitored until the induction was concluded and hematopoietic recovery started. Results: 38 patients, 15 women and 23 men with a mean age of 44 years (16-72), with acute lymphoblastic leukemia 19, myeloblastic 16 and promyelocytic 3. Cases without and with intestinal amebiasis were 35 and 3, respectively. Patients with amebiasis only received tinidazole for 3 days and it was given 2 days after the CT started. Conclusion: Tinidazole, in patients with acute de novo leukemia who initiate induction CT, is effective in the prevention of intestinal amebiasis, during the induction stage, if administered at 2 g/day, for five days, starting on day 1 of the CT.

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.

Myenteric plexus is differentially affected by infection with distinct Trypanosoma cruzi strains in Beagle dogs

Chagasic megaoesophagus and megacolon are characterised by motor abnormalities related to enteric nervous system lesions and their development seems to be related to geographic distribution of distinct Trypanosoma cruzi subpopulations. Beagle dogs were infected with Y or Berenice-78 (Be-78) T. cruzi strains and necropsied during the acute or chronic phase of experimental disease for post mortem histopathological evaluation of the oesophagus and colon. Both strains infected the oesophagus and colon and caused an inflammatory response during the acute phase. In the chronic phase, inflammatory process was observed exclusively in the Be-78 infected animals, possibly due to a parasitism persistent only in this group. Myenteric denervation occurred during the acute phase of infection for both strains, but persisted chronically only in Be-78 infected animals. Glial cell involvement occurred earlier in animals infected with the Y strain, while animals infected with the Be-78 strain showed reduced glial fibrillary acidic protein immunoreactive area of enteric glial cells in the chronic phase. These results suggest that although both strains cause lesions in the digestive tract, the Y strain is associated with early control of the lesion, while the Be-78 strain results in progressive gut lesions in this model.

Colitis por citomegalovirus en pacientes con síndrome de inmunodeficiencia adquirida: correlación histopatológica, endoscópica y clínica / Cytomegalovirus colitis in AIDS patients

La frecuencia de infección por citomegalovirus (CMV) en 199 biopsias de colon y recto de pacientes con síndrome de inmunodeficiencia adquirida (SIDA) fue de 28 por ciento. En 44 de ellas (23 por ciento), el CMV fue el único agente oportunista. Los cambios citopáticos que permitieron establecer el diagnóstico fueron: citomegalia, inclusiones citoplásmicas y vasculitis. El CMV se localizó principalmente en el estroma de la lámina propia y en el endotelio; el daño vascular se observó solamente en los vasos de la submucosa. Los hallazgos histológicos se correlacionaron con el aspecto macroscópico durante la endoscopia y con los síntomas, sin que hayan sido significativos.