Diagnostic criteria and case definitions for abdominal angiostrongyliasis: a systematic review from the Brazilian experience.

Although rare, Angiostrongylus costaricensis infection may be a more prevalent etiology of inflammatory bowel disease than ulcerative colitis and Chron's disease in endemic areas in Central and South America. The present study reviewed the occurrence of A. costaricensis in Brazil, its clinical presentation and pathology; and proposed diagnostic criteria and case definitions for abdominal angiostrongyliasis (AA). Southern and southeastern Brazilian regions are the main endemic areas, and AA affects both genders and all age groups. A review of all 23 published reports of 51 Brazilian patients highlighted the following features that were subsequently classified as minor diagnostic criteria: abdominal pain, palpable mass in the right lower abdominal quadrant, history of exposure, ileocecal tumor, and intestinal perforation with wall thickening. Proposed major criteria include right lower quadrant abdominal pain, blood eosinophilia, positive serology (antibody detection), intense eosinophilic infiltration that involves all strata of the intestinal wall, eosinophilic granulomatous reaction, and eosinophilic vasculitis. In addition to the definitions of suspected and possible cases according to increasing strength of evidence of this infection, demonstration of worms/eggs/larvae in tissues or Angiostrongylus DNA in tissues or serum are required for a confirmed diagnosis. The application of the proposed criteria and definitions may improve patient management, epidemiologic surveillance, and identification of new endemic areas.

A practical guide for the diagnosis of abdominal angiostrongyliasis caused by the nematode Angiostrongylus costaricensis.

Abdominal angiostrongyliasis (AA) is a severe parasitic infection caused by the nematode Angiostrongylus costaricensis. This disease is characterized by abdominal pain, a strong inflammatory eosinophilic response in the blood and tissues, and eventually intestinal perforation. Diagnosis of AA is challenging since there are no commercially available serological kits for A. costaricensis, and thus, histopathological analysis remains the gold standard. Herein we provide a decision flowchart for clinicians to improve the diagnosis of AA based on a patient's clinical manifestations, laboratory findings, macroscopic observations of the gut lesions, as well as characteristic microscopic alterations in biopsies. A brief discussion of the available polymerase chain reaction and in-house serological methods is also presented. The aim of this mini-review is to improve the diagnosis of AA, which should lead to prompt detection of cases and better estimates of the epidemiology and geographical distribution of A. costaricensis.

Perforación cecal por angiostrongiliasis en un adulto mayor / Cecal perforation due to angiostrongyliasis in an elderly patient

La angiostrongiliasis abdominal es una enfermedad parasitaria causada por el género Angiostrongylus costaricensis, un nematodo que infecta a los humanos a través de las secreciones de caracoles o babosas, sus huéspedes definitivos. Costa Rica es el país que se considera más endémico, se ha evidenciado en distintas revisiones que la mayoría de los casos se presentan en niños y personas del sexo masculino. Presentación del caso. Se trata de una mujer de 74 años, que consultó por dolor abdominal agudo, de cuatro días de evolución, acompañado de náuseas, vómitos e hiporexia. Los exámenes de laboratorio reportaron leucocitosis leve y examen general de orina negativo. La ultrasonografía abdominal reportó una masa sólida, heterogénea, mal circunscrita en flanco derecho, esto llevó a la sospecha de una apendicitis aguda. Intervención terapéutica. Se realizó una laparotomía exploradora, con la extirpación de una tumoración de colon perforado que abarcaba desde el ciego hasta el tercio proximal de colon ascendente, además, se realizó una anastomosis de íleo transversa, sin mayor complicación. Evolución clínica. Se manejó con antibióticos y analgésicos, fue dada de alta a los nueve días posteriores al procedimiento, sin complicaciones menores. La biopsia reportó huevos de parásitos consistentes con Angiostrongylus sp

bdominal angiostrongyliasis is a parasitic disease caused by the genus Angiostrongylus costaricensis, a nematode that infects humans through the secretions of snails or slugs, its definitive hosts. Costa Rica is considered the most endemic country, and it has been shown in different reviews that most cases occur in children and males. Case presentation. The patient was a 74-year-old woman who consulted for acute abdominal pain, with four days of evolution, accompanied by nausea, vomiting, and hyporexia. Laboratory tests reported mild leukocytosis and a negative general urine test. Abdominal ultrasonography reported a solid heterogeneous mass, poorly circumscribed in the right lateral abdomen, which led to the suspicion of acute appendicitis. Treatment. An exploratory laparotomy was performed, with the removal of a perforated colon tumor that spanned from the cecum to the proximal third of the ascending colon, in addition, a transverse ileum anastomosis was performed, without further complication. Outcome. She was managed with antibiotics and analgesics and was discharged nine days after the procedure, without complications. The biopsy showed parasite eggs consistent with Angiostrongylus sp

Abdominal angiostrongyliasis in the Americas: fifty years since the discovery of a new metastrongylid species, Angiostrongylus costaricensis.

Angiostrongylus costaricensis is a zoonotic parasitic nematode described for the first time in 1971 by Pedro Morera and Rodolfo Céspedes in Costa Rica. This parasite causes an infection known as abdominal angiostrongyliasis, affecting mainly school-aged children and young adults. Infection with A. costaricensis has been associated with a myriad of rodent and mollusk species in the Americas and the Caribbean, as its natural hosts and reservoirs. In this commemorative review, we highlight the extensive research collected through a 50-year journey, which includes ecological, pathological, and molecular studies on A. costaricensis and its implicated disease. We also identify major knowledge gaps in its evolutionary history, the ecological role of imported and invasive mollusk species, and immune response. We propose that the advent of -omics analyses will allow us to gather novel information regarding A. costaricensis biology and infection dynamics, as well as to promote the design of much-needed sensitive and specific diagnostic tools.

Prevalence of Angiostrongylus cantonensis and Angiostrongylus costaricensis in Achatina fulica snails in the municipality of São Bernardo do Campo (SP, Brazil) / Prevalência de Angiostrongylus cantonensis e Angiostrongylus costaricensis em caramujos Achatina fulica na cidade de São Bernardo do Campo (SP, Brasil)

Angiostrongylus cantonensis e Angiostrongylus costaricensis são nematoides parasitas que residem em roedores e usam gastrópodes como hospedeiros intermediários. Achatina fulica, conhecida como caramujo-gigante-africano, é um hospedeiro intermediário que desempenha importante papel na dispersão de A. cantonensis e A. costaricensis, patógenos zoonóticos que causam, respectivamente, meningoencefalite eosinofílica e angiostrongilíase abdominal em humanos. O objetivo deste estudo foi o de coletar caramujos (A. fulica, n=90) de oito regiões diferentes (Rudge Ramos, Baeta Neves, Planalto, Demarchi, Dos Alvarengas, Batistini, Montanhão, Rio Grande) da cidade de São Bernardo do Campo (SP) para detecção molecular de A. cantonensis ou A. costaricensis pela técnica de reação em cadeia da polimerase (PCR). As amostras foram processadas em pools (n=25) segundo a região de coleta. Com exceção da região de Baeta Neves, as demais apresentaram caramujos infectados com larvas de nematoides. Seis regiões apresentaram amostras positivas para A. cantonensis. Quatorze (56%) das 25 amostras em pool apresentaram larvas de nematoides, e 52% delas (13/25) foram positivas para A. cantonensis. Nenhuma amostra positiva para A. costaricensis foi encontrada. A presença de A. fulica naturalmente infectada por A. cantonensis deve servir como um alerta para as autoridades de saúde pública sobre o risco potencial de infecção para humanos.(AU)

Angiostrongylus costaricensis, un parásito neotropical cuyo diagnóstico y tratamiento siguen siendo controversiales

La angiostrongilosis abdominal es una parasitosis esporádica, que ocurre en países del neotrópico, especialmente en Costa Rica. Es una enfermedad cuyo diagnóstico es infrecuente y su tratamiento controversial. Se presenta un caso de un adulto que muestra un malestar generalizado, dolor abdominal y una intensa eosinofilia que lleva a la detección de una masa en la fosa iliaca inferior derecha. El diagnóstico definitivo se hace mediante la prueba de Morera y el tratamiento incluye el uso de azitromicina y metronidazol, no obstante no se usan antihelmínticos ni se realiza cirugía. El caso descrito pone de manifiesto que tanto el diagnóstico como el tratamiento de esta enfermedad parasitaria continúan siendo inciertos. No se descarta que exista un subregistro importante de esta parasitosis o que los síntomas sean confundidos con otras patologías.

Abdominal angiostrogyliasis is a sporadic parasitosis that occurs in Neotropical countries, mainly in Costa Rica. It is a disease with an infrequent diagnosis and a controversial treatment. We discuss a case of an adult that presents a severe generalized discomfort, abdominal pain and an intense eosinophilia that leads to the detection of a mass at the right lower quadrant. Definitive diagnosis is achieved by the Morera Test and the treatment includes the use of azythromicin and metronidazole: no antihelmintic drugs or surgery were used. The case shows that both the diagnosis and treatment of this parasitosis are uncertain. An important underreporting of the disease may occur, as well as confusion of the symptoms with other pathologies.

Abdominal Angiostrongyliasis: A Presentation of Eosinophilic Granulomatous Colitis.

We present a case of a 4-year-old girl with abdominal angiostrongyliasis who presented with persistent fevers, hepatosplenomegaly, acute abdominal pain, and eosinophilia. Computed tomography scan identified thickening of the ascending colon with a narrowed lumen. Endoscopic evaluation revealed ulcerations and erythema in the ascending colon. The microscopic findings in biopsies included active chronic inflammation with prominent eosinophils and granulomas. A subset of granulomas contained the eggs of Angiostrongylus costaricensis. The definitive method of diagnosing A costaricensis is histology; peripheral blood serology has low specificity and the stool from infected patients does not contain eggs or larvae. Pathologists from endemic regions (Central and South America) are familiar with the typical histologic changes; however, because of increasing global travel, all pathologists should become familiar with A costaricensis, which may mimic common gastrointestinal diseases such as Crohn's disease, appendicitis, and Meckel's diverticulum.

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.

Morphological aspects of Angiostrongylus costaricensis by light and scanning electron microscopy.

Angiostrongylus costaricensis is a parasitic nematode that can cause severe gastrointestinal disease, known as abdominal angiostrongiliasis, in humans. This paper presents the characterization of first- and third-stage larvae and male and female adult worms of A. costaricensis by scanning electron and light microscopy. Several novel anatomical structures were identified by scanning electron microscopy, including details of the cuticular striations of the spicules in male worms and a protective flap of the cuticle covering the vulvar aperture in female worms. Other taxonomic features revealed by light microscopy include the gubernaculum and the esophageal-intestinal valve. The use of two microscopy techniques allowed a detailed characterization of the morphology of this nematode. A number of previously identified taxonomic features, such as the striated nature of the spicules and the lateral alae were confirmed; however, the use of scanning electron microscopy resulted in a reassessment of the correct number of papillae distributed around the oral opening and behind the cloacal opening. These observations, in combination with light microscopy-based characterization of the gubernaculum and esophageal valves, have allowed a more detailed description of this nematode taxonomy.

Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis

Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1) were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3) were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.

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.

Use of heterologous antigens for the immunodiagnosis of abdominal angiostrongyliasis by an enzyme-linked immunosorbent assay

Angiostrongylus costaricensis has a broad geographic distribution spanning from North to South America and the infections of vertebrates with this nematode can result in abdominal complications. Human infections are diagnosed by histological or serological methods because the isolation of larvae from feces is not feasible, as most parasites become trapped in intestinal tissues due to intense eosinophilic inflammation. Because A. costaricensis is difficult to maintain in the laboratory, an immunodiagnostic IgG enzyme-linked immunosorbent assay (ELISA) using antigens from the congeneric Angiostrongylus cantonensis species was evaluated against a panel of serum samples from patients who were histologically diagnosed with A. costaricensis infections. Sera from uninfected individuals and individuals infected with other parasites were used as controls. The sensitivity and specificity of the assay were estimated at 88.4 percent and 78.7 percent, respectively. Because the use of purified or cloned antigens has not been established as a reliable diagnostic tool, the use of heterologous antigens may provide a viable alternative for the development of an ELISA-based immunodetection system for the diagnosis of abdominal angiostrongyliasis.

Susceptibility and morbidity between male and female Swiss mice infected with Angiostrongylus costaricensis: Susceptibilidade e morbidade entre camundongos Swiss machos e fêmeas infectados com Angiostrongylus costaricensis

The gender of vertebrate hosts may affect the outcome of parasitic infections. An experimental murine infection with Angiostrongylus costaricensis was followed with determinations of body weight, fecal larval elimination, number and length of adult worms, number of macroscopic intestinal lesions, and mortality. Groups of male and female Swiss mice were infected with 10 3rd-stage A. costaricensis larvae per animal. The results indicate there are no significant differences related to gender of the host, except for higher length of worms developed in male mice.

O sexo dos hospedeiros vertebrados pode influenciar no resultado de infecções parasitárias. A infecção experimental de camundongos com Angiostrongylus costaricensis foi acompanhada com observação do peso corporal, eliminação de larvas nas fezes, número e comprimento dos vermes adultos, número de lesões macroscópicas nos intestinos e mortalidade. Grupos de camundongos Swiss machos e fêmeas foram infectados cada um com 10 larvas de terceiro estágio de A. costaricensis. Os resultados indicam que não há diferenças significativas relacionados ao sexo dos hospedeiros, exceto pelo maior comprimento dos vermes nos hospedeiros machos.

Attractionof Schistosoma mansoni Sambon, 1907 miracidia to Biomphalaria glabrata (Say, 1818) in the presence of Angiostrongylus costaricensis Morera and Céspedes, 1971 infection / Atração de miracídios de Schistosoma mansoni Sambon, 1907 por Biomphalaria glabrata (Say, 1818) infectada por Angiostrongylus costaricensis Morera and Céspedes, 1971

The attraction exerted by Biomphalaria glabrata infected with Angiostrongylus costaricensis on Schistosoma mansoni miracidia of the BH strain was tested, using a glass apparatus composed by two circular chambers connected to a channel. One mollusk or a sample of a snail conditioning water (SCW) was placed in one of the chambers, randomly selected, and the remaining of the apparatus was filled with chlorine-free water. Ten miracidia were placed in the centre of the channel and their behaviour was observed for 15 minutes. Ten replicates were made for each treatment (snail or SCW), using different specimens of mollusks or different samples of SCW. Mollusks infected with A. costaricensis attracted significantly less S. mansoni miracidia than non-infected B. glabrata. In addition, miracidia were also significantly more attracted to SCW from mollusks infected with A. costaricensis.

Utilizando-se um artefato de vidro composto por duas câmaras unidas por um canal, testamos a atração miraxonal exercida por Biomphalaria glabrata infectada por Angiostrongylus costaricensis sobre miracídios de Schistosoma mansoni da linhagem BH. Um molusco ou uma amostra de sua água de condicionamento (SCW) foi colocado aleatoriamente em uma das câmaras, sendo o restante do artefato preenchido com água declorada. Dez miracídios foram colocados no centro do canal e seu comportamento foi observado por 15 minutos. Foram feitas dez replicações de cada experimento utilizando-se espécimes de moluscos ou de amostras de SCW diferentes. Moluscos infectados com A. costaricensis atraíram significativamente menos miracídios de S. mansoni que B. glabrata não infectada. Além disso, miracídios foram significativamente mais atraídos pela SCW de moluscos infectados com A. costaricensis.

Attractionof Schistosoma mansoni Sambon, 1907 miracidia to Biomphalaria glabrata (Say, 1818) in the presence of Angiostrongylus costaricensis Morera and Céspedes, 1971 infection

The attraction exerted by Biomphalaria glabrata infected with Angiostrongylus costaricensis on Schistosoma mansoni miracidia of the BH strain was tested, using a glass apparatus composed by two circular chambers connected to a channel. One mollusk or a sample of a snail conditioning water (SCW) was placed in one of the chambers, randomly selected, and the remaining of the apparatus was filled with chlorine-free water. Ten miracidia were placed in the centre of the channel and their behaviour was observed for 15 minutes. Ten replicates were made for each treatment (snail or SCW), using different specimens of mollusks or different samples of SCW. Mollusks infected with A. costaricensis attracted significantly less S. mansoni miracidia than non-infected B. glabrata. In addition, miracidia were also significantly more attracted to SCW from mollusks infected with A. costaricensis.

Utilizando-se um artefato de vidro composto por duas câmaras unidas por um canal, testamos a atração miraxonal exercida por Biomphalaria glabrata infectada por Angiostrongylus costaricensis sobre miracídios de Schistosoma mansoni da linhagem BH. Um molusco ou uma amostra de sua água de condicionamento (SCW) foi colocado aleatoriamente em uma das câmaras, sendo o restante do artefato preenchido com água declorada. Dez miracídios foram colocados no centro do canal e seu comportamento foi observado por 15 minutos. Foram feitas dez replicações de cada experimento utilizando-se espécimes de moluscos ou de amostras de SCW diferentes. Moluscos infectados com A. costaricensis atraíram significativamente menos miracídios de S. mansoni que B. glabrata não infectada. Além disso, miracídios foram significativamente mais atraídos pela SCW de moluscos infectados com A. costaricensis.

Abdominal angiostrongyliasis: report of two cases with different clinical presentations / Angiostrongilíase abdominal: relato de dois casos com diferentes apresentações clínicas

Abdominal angiostrongyliasis is a sporadic infectious disease caused by the nematode Angiostrongylus costaricensis. It usually presents as acute abdomen, secondary to mesenteric ischemia, and pronounced eosinophilia. In some cases its course is insidious and transient, and the diagnosis is suspicious. The disease is confirmed by the detection of A. costaricensis elements in surgical specimen. The treatment is supportive, with avoidance of antihelminthic administration due to a possible erratic migration followed by worsening of the disease. We report two cases, both with intense eosinophilia and serum IgG-ELISA positive to A. costaricensis. The first case presented ileal perforation and was surgically treated. The second one showed hepatic nodules at ultrasound and was only symptomatically treated, evolving to an apparent protracted resolution. These two cases exemplify different clinical forms of the disease, one of them with liver involvement.

A angiostrongilíase abdominal é doença esporádica decorrente da infecção pelo nematódeo Angiostrongylus costaricensis. Costuma manifestar-se como abdome agudo secundário a isquemia mesentérica, além de marcada eosinofilia. Pode também apresentar-se de forma insidiosa e transitória, exigindo alta suspeita clínica para o diagnóstico. A doença é confirmada pela identificação de elementos do A. costaricensis em peças cirúrgicas. O tratamento é apenas de suporte, devendo-se evitar o uso de anti-helmínticos pela possibilidade de migração errática do verme com piora do quadro. Aqui foram apresentados dois casos, ambos com acentuada eosinofilia e ELISA-IgG sérico positivo para A. costaricencis. O primeiro caso cursou com perfuração ileal e foi tratado cirurgicamente. O segundo caso apresentou nódulos hepáticos ao ultrassom e foi tratado sintomaticamente, evoluindo para lenta resolução. Estes dois casos exemplificam diferentes formas de apresentação clínica da doença, uma delas com envolvimento hepático.