Characterisation of the vascular pathology in Sigmodon hispidus (Rodentia: Cricetidae) following experimental infection with Angiostrongylus costaricensis (Nematoda: Metastrongylidae)

BACKGROUND Angiostrongylus costaricensis is a nematode that causes human abdominal angiostrongyliasis, a disease found mainly in Latin American countries and particularly in Brazil and Costa Rica. Its life cycle involves exploitation of both invertebrate and vertebrate hosts. Its natural reservoir is a vertebrate host, the cotton rat Sigmodon hispidus. The adult worms live in the ileo-colic branches of the upper mesenteric artery of S. hispidus, causing periarteritis. However, there is a lack of data on the development of vasculitis in the course of infection. OBJECTIVE To describe the histopathology of vascular lesions in S. hispidus following infection with A. costaricensis. METHODS Twenty-one S. hispidus were euthanised at 30, 50, 90 and 114 days post-infection (dpi), and guts and mesentery (including the cecal artery) were collected. Tissues were fixed in Carson’s Millonig formalin, histologically processed for paraffin embedding, sectioned with a rotary microtome, and stained with hematoxylin-eosin, resorcin-fuchsin, Perls, Sirius Red (pH = 10.2), Congo Red, and Azan trichrome for brightfield microscopy analysis. FINDINGS At 30 and 50 dpi, live eggs and larvae were present inside the vasa vasorum of the cecal artery, leading to eosinophil infiltrates throughout the vessel adventitia and promoting centripetal vasculitis with disruption of the elastic layers. Disease severity increased at 90 and 114 dpi, when many worms had died and the intensity of the vascular lesions was greatest, with intimal alterations, thrombus formation, iron accumulation, and atherosclerosis. CONCLUSION In addition to abdominal angiostrongyliasis, our data suggest that this model could be very useful for autoimune vasculitis and atherosclerosis studies.

Abdominal angiostrongyliasis with involvement of liver histopathologically confirmed: a case report / Angiostrongiliasis abdominal con lesión hepática histopatológicamente confirmada

Human abdominal angiostrongyliasis is a zoonotic disease caused by ingestion of the L3 larvae of Angiostrongylus costaricensis. The human infection gives rise to a pathological condition characterized by acute abdominal pain, secondary to an inflammatory granulomatous reaction, marked eosinophilia and eosinophilic vasculitis. Most commonly this disease is limited to intestinal location, primary ileocecal, affecting the mesenteric arterial branches and intestinal walls. We present one of the few cases reported around the world with simultaneous involvement of the intestines and liver, including proved presence of nematodes inside the hepatic arteriole.

La enfermedad conocida como angiostrongiliasis abdominal humana es una zoonosis causada por la ingestión del estadio larval L3 de Angiostrongylus costaricensis. En el ser humano, esta infección provoca un estado patológico caracterizado por dolor abdominal agudo, secundario a una reacción inflamatoria granulomatosa; eosinofilia marcada y vasculitis eosinofílica. Comúnmente el cuadro se encuentra limitado a una localización intestinal, predominantemente ileocecal, que compromete las ramas de la arteria mesentérica y la pared intestinal. Presentamos uno de los pocos casos reportados alrededor del mundo con hallazgos simultáneos en intestino e hígado; se incluye la demostración histológica del nemátodo dentro de la arteriola hepática.

Abdominal angiostrongyliasis: a case with severe evolution

É relatado um caso de abdome agudo causado por angiostrongilíase abdominal. Um paciente de 42 anos, previamente hígido, apresentou queixa de nove dias de dor abdominal, constipação, disúria, febre e uma massa palpável na fossa ilíaca direita. Uma laparotomia exploradora foi realizada. Após o tratamento cirúrgico o paciente apresentou graves complicações.

Angiostrongylus costaricensis: complete redescription of the migratory pathways based on experimental Sigmodon hispidus infection

Angiostrongylus costaricensis lives in the cecal and mesenteric arteries of its vertebrate hosts, and causes an inflammatory disease in humans. To investigate unknown aspects of the abdominal angiostrogyliasis pathogenesis, infected Sigmodon hispidus were sequentially studied in different times of infection. The study revealed that L3 goes alternatively through two migratory courses during its development into an adult worm: lymphatic/venous-arterial and venous portal pathways. The former is considered the principal one, because it is used by most of the larvae. Like other metastrongylides, A. costaricensis passes over the pulmonary circulation to migrate from the lymphatic system to the arterial circulation, where they circulate during some days before reaching their definitive habitat. The oviposition by mature females began on 15th day. Eggs and L1 were detected mainly in the intestine and stomach, surrounded by inflammatory reaction constituted by macrophages, monocytes, and eosinophils. They were also spread to the lungs, mesenteric lymph nodes, pancreas, spleen, and kidneys. The larvae (L1) exhibited the centripetal capacity to invade the lymphatic and venous vessels of the intestine and mesentery. Adult worms that developed in the venous intrahepatic pathway migrated downstream to reach the mesenteric veins and laid eggs that embolized in the portal hepatic vessels.

Angiostrongilíase abdominal: relato de possível caso autóctone do Rio de Janeiro / Abdominal angiostrongyliasis: report a probable autocton case from Rio de Janeiro

Apresentamos o primeiro caso de angiotrongilíase abdominal, com possibilidade de ser autóctone, do Rio de Janeiro. Inicialmente o quadro clínico era de febre prolongada e eosinofilia maciça, evoluindo com abdome agudo por perfuraçao de alça, peritonite, sepse e necrose hepática. A histopatologia do segmento ressecado e da biopsia hepática confirmou a presença de verme intra-arterial, arterite e granuloma eosinofílicos. Sao abordados os aspectos clínicos e patológicos desta doença rara e potencialmente grave. É enfatizada a importância de se evitar emprego indiscriminado de anti-helmínticos baseando-se apenas na eosinofilia, sem identificaçao do parasita através de exames de fezes.