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.

Pulmonary arterial response to Angiostrongylus vasorum in naturally infected dogs: echocardiographic findings in two cases.

BACKGROUND: Angiostrongylus vasorum is a nematode living in the pulmonary arteries of canids. Infected dogs develop severe pulmonary lesions which can potentially lead to pulmonary hypertension (PH). However, reports of PH in natural infected dogs are scant. One of the possible causes of the low prevalence of PH in A. vasorum-infected dogs could be the establishment of large diameter intrapulmonary arteriovenous anastomoses (IPAVAs), which attenuate pulmonary vascular resistance, thus reducing the pulmonary arterial pressure. The present report describes the pulmonary arterial pressure (PAP) response to A. vasorum natural infection in two dogs, assessed by echocardiography and by the saline contrast echocardiographic test (SCE). RESULTS: Both dogs showed clinical signs of respiratory disease. At presentation, case 1 did not show echocardiographic signs of PH and the SCE test was positive proving the presence of IPAVAs. However, at the follow-up visit, despite A. vasorum infection resolution, the same dog showed PH and the SCE test resulted negative, which ruled out the presence of IPAVAs. Case 2 suffered from severe pulmonary arterial hypertension and right-side congestive heart failure since the day of presentation. Saline contrast echocardiography was negative both at the time of presentation and at the follow-up visit. CONCLUSIONS: In the two cases described above, the PH was not associated with IPAVAs. During A. vasorum infection, IPAVAs recruitment mechanism is able to contrast the rise of PAP until a certain level. It probably represents an initial escape mechanism of PH that, over time, exhausts its compensatory capacities allowing PAP to rise and to be detectable on echocardiography.

Angiostrongylus vasorum in the eye: new case reports and a review of the literature.

BACKGROUND: Nematodes of the genus Angiostrongylus are important causes of potentially life-threatening diseases in several animal species and humans. Angiostrongylus vasorum affects the right ventricle of the heart and the pulmonary arteries in dogs, red foxes and other carnivores. The diagnosis of canine angiostrongylosis may be challenging due to the wide spectrum of clinical signs. Ocular manifestations have been seldom reported but have serious implications for patients. METHODS: The clinical history of three cases of infection with A. vasorum in dogs diagnosed in UK, France and Italy, was obtained from clinical records provided by the veterinary surgeons along with information on the diagnostic procedures and treatment. Nematodes collected from the eyes of infected dogs were morphologically identified to the species level and molecularly analysed by the amplification of the nuclear 18S rRNA gene. RESULTS: On admission, the dogs were presented with various degrees of ocular discomfort and hyphema because of the presence of a motile object in the eye. The three patients had ocular surgery during which nematodes were removed and subsequently morphologically and molecularly identified as two adult males and one female of A. vasorum. CONCLUSIONS: Three new cases of canine ocular angiostrongylosis are reported along with a review of other published clinical cases to improve the diagnosis and provide clinical recommendation for this parasitic condition. In addition, the significance of migratory patterns of larvae inside the host body is discussed. Veterinary healthcare workers should include canine angiostrongylosis in the differential diagnosis of ocular diseases.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Low susceptibility of Achatina fulica from Brazil to infection with AngioIylus costaricensis and A. cantonensis

Introduction of Achatina fulica in Brazil has led to serious concerns about its role as vector for metaIylid worms: AngioIylus costaricensis and A. cantonensis. Experimental infection with both parasites was performed to evaluate the potential risk for their transmission by the giant African snail. Groups of 5 animals, both wild and bred at captivity were exposed at different inocula: 1, 5, and 10 ´ 10³ L1 of A. costaricensis and A. cantonensis. In all groups, few snails got infected and parasitic burden was low. Two different ways of infection were tested: ingestion produced higher numbers of L3 than the inoculation through an artificial hole in the shell. We also report the parasitological examination of 6 batches of wild A. fulica from Florianópolis, state of Santa Catarina, Brazil: only 1 out of 244 animals were infected with metaIylid larvae. Taken together these data indicate that the giant African snail occurring in Southern Brazil is not a permissive host for both AngioIylus species and does not represent a significant risk for transmission of these parasites.

Behavior of Angiostrongylus costaricensis in planorbids

Alguns moluscos terrestres são hospedeiros naturais do Angiostrongylus costaricensis. No laboratório, esse nematódeo pode ser mantido em planorbídeos, que são moluscos aquáticos e hospedeiros intermediários do Schistosoma mansoni. Os moluscos podem ser infectados com A. costaricensis por ingestão ou por penetração ativa de larvas de primeiro estágio. Neste trabalho, testamos a habilidade de Biomphalaria glabrata em atrair larvas de primeiro estágio de A. costaricensis. A movimentação das larvas do nematódeo em direção aos moluscos foi observada após 15 minutos, 30 minutos e 1 hora. B. glabrata não atraiu as larvas de primeiro estágio de A. costaricensis nos três intervalos de tempo. Verificamos também a suscetibilidade de duas populações de Biomphalaria tenagophila à infecção por A. costaricensis. Uma população era selecionada geneticamente para a susceptibilidade ao S. mansoni, enquanto a outra não o era. Larvas de terceiro estágio foram recuperadas dos moluscos 30 dias após a exposição das duas populações a 120 larvas de primeiro estágio. Todos os moluscos estavam infectados. Entretanto, um número significativamente maior de larvas de terceiro estágio foi recuperado em moluscos não geneticamente selecionados.

In vitro maintenance of Angiostrongylus costaricensis does not provide physiological conditions for egg laying

Quinze duplas (macho/fêmea) de Angiostrongylus costaricensis foram mantidas in vitro, em meio de Waymouth durante 3 dias, para observação da quantidade e duração da oviposição. Médias de 321, 24 e 4 ovos em 10 microlitros foram registradas em 24, 48 e 72 horas, respectivamente. A maioria dos ovos foi eliminada nas primeiras 24 horas, sugerindo terem sido expulsos em condições não fisiológicas. Estes resultados indicam que as condições in vitro não são adequadas para testes de drogas inibidoras da oviposição, para tratamento da angiostrongilíase abdominal.

Angiostrongylus costaricensis and experimental infection of Sarasinula marginata II: elimination routes.

Angiostrongylus costaricensis intermediate hosts are terrestrial mollusks mostly belonging to the Veronicellidae family. In the present investigation we focused on the mechanisms of larval expulsion from Sarasinula marginata infected with A. costaricensis. Twenty-five mollusks were individually infected with 5000 L1 and sacrificed at 30 min and 1, 2, 4, 6, and 8 h post-infection and at days 1, 2, 4, 5, 6, 8, 10, 11, 12, 14, 15, 16, 20, 21, 22, 25, 26, 28, and 30 post-infection; the mollusks were then fixed and stained. Diverse organs involved throughout the course of the migratory routes of larvae from oral penetration on were specified and the mechanisms of larval access to the fibromuscular layer through the kidney, rectum, and vascular system were defined. The elimination of L3, derived from oral and/or cutaneous infections, appears to depend on granulomas located close to the excretory ducts of mucous cells.

Penetration sites and migratory routes of Angiostrongylus costaricensis in the experimental intermediate host (Sarasinula marginata).

The intermediate hosts of Angiostrongylus costaricensis are terrestrian molluscs, mostly of the family Veronicellidae. The present work aimed at clarifying more accurately the sites of penetration and the migratory routes of A. costaricensis in the tissue slugs and at verifying the pattern of the perilarval reaction at different times of infection. Slugs were individually infected with 5,000 L1, and killed from 30 min to 30 days after infection. From 30 min up to 2 hr after infection, L1 were found within the lumen of different segments of the digestive tube having their number diminished in more advanced times after exposition until complete disappearance. After 30 min of exposition, percutaneous infection occurred, simultaneously to oral infection. Perilarval reaction was observed from 2 hr of infection around larvae in fibromuscular layer, appearing later (after 6 hr) around larvae located in the viscera. A pre-granulomatous reaction was characterized by gradative concentration of amebocytes around larvae, evolving two well-organized granulomas. In this work we confirmed the simultaneous occurrence of oral and percutaneous infections. Perilarval reaction, when very well developed, defined typical granulomatous structure, including epithelioid cell transformation. The infection also caused a systemic mobilization of amebocytes and provoked amebocyte-endothelium interactions.

The effect of temperature on mobility of Angiostrongylus costaricensis third stage larvae

Third stage larvae (L3) from Angiostrongylus costaricensis were incubated in water at room temperature and at 5 §C and their mobility was assessed daily for 17 days. Viability was associated with the mobility and position of the L3, and it was confirmed by inoculation per os in albino mice. The number of actively moving L3 sharply decreased within 3 to 4 days, but there were some infective L3 at end of observation. A mathematical model estimated 80 days as the time required to reduce the probability of infective larvae to zero. This data does not support the proposition of refrigerating vegetables and raw food as an isolated procedure for prophylaxis of human abdominal angiostrongylosis infection

Penetration Sites and Migratory Routes of Angiostrongylus costaricensis in the Experimental Intermediate Host (Sarasinula marginata)

The intermediate hosts of Angiostrongylus costaricensis are terrestrian molluscs, mostly of the family Veronicellidae. The present work aimed at clarifying more accurately the sites of penetration and the migratory routes of A. costaricensis in the tissue slugs and at verifying the pattern of the perilarval reaction at different times of infection. Slugs were individually infected with 5,000 L1, and killed from 30 min to 30 days after infection. From 30 min up to 2 hr after infection, L1 were found within the lumen of different segments of the digestive tube having their number diminished in more advanced times after exposition until complete disappearance. After 30 min of exposition, percutaneous infection occurred, simultaneously to oral infection. Perilarval reaction was observed from 2 hr of infection around larvae in fibromuscular layer, appearing later (after 6 hr) around larvae located in the viscera. A pre-granulomatous reaction was characterized by gradative concentration of amebocytes around larvae, evolving two well-organized granulomas. In this work we confirmed the simultaneous occurrence of oral and percutaneous infections. Perilarval reaction, when very well developed, defined typical granulomatous structure, including epithelioid cell transformation. The infection also caused a systemic mobilization of amebocytes and provoked amebocyte-endothelium interactions

Angiostrongylus costaricensis and the intermediate hosts: observations on elimination of L3 in the mucus and inoculation of L1 through the tegument of mollucs

A infecção acidental humana por Angiostrongylus costaricensis pode resultar em doença abdominal de variada gravidade. Veronicelídeos são os principais moluscos hospedeiros intermediários do Angiostrongylus costaricensis, nematódeo parasita de roedores. Foi comparada a cinética de eliminação de larvas de terceiro estágio (L3) no muco através da infecção experimental de Phyllocaulis variegatus, P. soleiformis e P. boraceiensis. Um máximo de 2 L3/g/dia foi observado no muco, enquanto o número de larvas isoladas dos tecidos fibromusculares variou 14 e 448. A injeção das larvas no hiponoto ou na cavidade tegumentar estabeleceu infecção produtiva. A via intra-cavitária permite melhor controle de inóculo e envolve procedimento mais simples. Titulação preliminar da dose infectante para P. variegatus sugere que os inóculos devem ficar entre 1000 e 5000 L1. Os dados também reforçam a importância de P. variegatus como hospedeiro intermediário do A. costaricensis.

Human accidental infection with Angiostrongylus costaricensis may result in abdominal disease of varied severity. Slugs from the Veronicellidae family are the main intermediate hosts for this parasitic nematode of rodents. Phyllocaulis variegatus, Phyllocaulis soleiformis and Phyllocaulis boraceiensis were experimentally infected to describe the kinetics of L3 elimination in the mucus secretions of those veronicelid species. A maximum of 2 L3/g/day was found in the mucus, while the number of L3 isolated from the fibromuscular tissues varied from 14 to 448. Productive infection was established by inoculations in the hyponotum or in the body cavity, through the tegument. Intra-cavity injection is a less complex procedure and permits a better control of inocula. A preliminary trial to titrate the infective dosis for P. variegatus indicated that inocula should range between 1000 and 5000 L1. The data also confirmed the importance of P. variegatus as an intermediate host of A. costaricensis.

[Human angiostrongyliasis caused by Angiostrongylus costaricensis]. / Angiostrongylose humaine à Angiostrongylus costaricensis.

Angiostrongylus costaricensis was discovered by Morera and Céspedes in 1971, in a man suffering from an abdominal syndrome. Upon surgery, worms were observed in the cranial mesenteric artery. These worms were assigned to the metastrongylid strongyles and to the genus Angiostrongylus, which was already known, in man medicine, by the species A. cantonensis, the causative agent of an eosinophilic meningitis. Morera's parasite was named Angiostrongylus costaricensis from the place where it was described. A costaricensis is a dixenic parasite, the definitive hosts (D.H.) of which are the cotton-rat (Sigmodon hispidus) and some other rodents. Experimentally, carnivora (Nasua spp: procyonidae) and monkeys (Saguinus mystax: hapalidae) are receptive, same as dogs. The intermediary hosts (I.H.) are slugs belonging to the Veronicellidae family (order gymnophila), mainly Vaginulus plebeius. In the D.H., the parasite produces eggs that hatch into first stage larvae (L1), which are expelled with faeces, eaten by slugs and become infective third stage larvae (L3). L3 are then expelled through mucoïd secretions of the slug and pollute soil and vegetables. D.H. and man get infected with consuming polluted vegetables or even the infected slugs themselves. L3 migrate through lymphatic system and arrive inside the mesenteric artery, where they become adults. In man, the worm can reach this adult egg-laying stage, but larvae are trapped inside granulomas in the intestinal wall and cannot evolve. So, man is a dead-lock for A. costaricensis. Angiostrongylosis costaricensis is an illustration of an hemi-zoonosis (the parasite cannot go back from man to animals) of the biological pattern.

On the diversity of mollusc intermediate hosts of Angiostrongylus costaricensis Morera & Cespedes, 1971 in southern Brazil

Veronicellid slugs are considered the most important intermediate hosts of Angiostrongylus costaricensis, an intra-arterial nematode of rodents. Studies undertaken in three localities in southern Brazil led to identification of molluscs other than veronicellid slugs as hosts of A. costaricensis: Limax maximus, Limax flavus and Bradybaena similaris. These data indicate a low host specificity of larval stages of A. costaricensis, as it has been reported to other congeneric species

Abdominal angiostrongyliasis in Nicaragua: a clinico-pathological study on a series of 12 cases reports.

A retrospective study was done to determine the presence of abdominal angiostrongyliasis in Nicaragua. Twelve cases of this parasitic disease were found among 48 visceral specimens: small intestine, liver and testes. The patients with intestinal lesions presented symptoms of an acute abdomen, and in some instances, a tumor-like mass was palpated in the lower right quadrant. A thickening of the intestinal wall accompanied by necrosis and perforation were the most important macroscopic findings. One patient with hepatic localisation of Angiostrongylus costaricencis displayed a clinical picture of visceral larva migrans-like syndrome. The chief laboratory findings were leukocytosis and eosinophilia. The histopathological examination showed granulomas and heavy eosinophilic infiltration around the eggs and larvae of A. costaricencis. Also, an adult worm was seen in one biopsy.

Identificacäo de roedores silvestres como hospedeiros do Angiostrongylus costaricensis no sul do Brasil / Identification of wild rodents as hosts of Angiostrongylus costaricencis in Southern Brazil

Um número de casos angiostrongilíase abdeominal tem sido detectado no sul do Brasil. O principal hospedeiro do Angiostrongylus costaricensis na América Central, o rato do algodäo (Sigmodon hispidus), näo ocorre na América do Sul, exceto no norte do Peru, Colômbia e Venezuela. Foram realizadas capturas na área endêmica do Rio Grande do Sul (RS), visando identificar hospedeiros para obtençäo de vermes em laboratório e produçäo de antígeno. Pela primeira vez no Brasil foi constatada a infecçäo em roedores: Oryzomys nigripes e Oryzomys ratticeps. O nigripes é um roedor silvestre de pequeno porte e parece ser o principal hospedeiro definitivo do A. costaricensis na regiäo serrana do RS

Ocorrência de Sarasinula marginata (Mollusca: Soleolifera) em Belo Horizonte, MG, Brasil / Occurrence of Sarasinula marginata (Mollusca: Soleolifera) in Belo Horizonte, MG, Brazil

The occurrence of Sarasinula marginata, a possible intermediate host of Angiostrongylus costaricensis, in the city of Belo Horizonte, MG, Brazil, is reported on

Phillocaulis variegatus - an intermediate host of Angiostrongylus costaricensis in south Brazil

Moluscos coletados em cinco localidades no estado do Rio Grande do Sul (Brasil) foram digeridos e examinados. As lesmas infectadas foram identificadas como Phyllocaulis variegatus e as larvas encontradas foram inoculadas per os em camundongos albinos. Após 50 dias, parasitos com as características de A. costaricensis foram recuperados do sistema arterial mesentérico. Estes resultados estabelecem o papel do P. variegatus como hospedeiro intermediário de A. costaricensis no sul do Brasil, onde diversos casos de angiostrongilíase abdominal têm sido diagnosticados

The intermediate host of Angiostrongylus costaricensis in Honduras

Se colectaron babosas (Veronicellidae) en el Departamento de Morazán, Honduras. La digestión con jugo gástrico artificial mostró la presencia de larvas de tercer estadio morfológicamente semejantes a Angiostrongylus costaricensis. Seles inculó les inoculó en ratas (Sigmodon hispidus) con sonda gástrica. Cincuenta días después se obtuvieron los nemátodos adultos y se confirmó el diagnóstico. A pesar de que se han encontrado casos humanos de angiostrongiliasis abdominal en Honduras, nunca se había encontrado el parásito en su huésped intermediario

Eosinophil responses of permissive and nonpermissive hosts to the young adult worms of Angiostrongylus cantonensis.

Blood and bone marrow eosinophilia was assessed in nonpermissive (guinea pigs) and permissive (rats) hosts following the pulmonary arterial transfers of live or dead young adult worms of Angiostrongylus cantonensis. Guinea pigs showed a marked eosinophilic response to live worms but only a slight response to dead worms. Neither IgE nor haemagglutinating antibodies correlated with the induction of this eosinophilia. In contrast, the rat responded to neither form of the young adult worm. When the guinea pig and the rat were injected with whole worm extract (WWE) of the young adult worms either by an osmotic mini-pump connected to the jugular vein or by intermittent intravenous injections, the former animal showed blood eosinophilia but the latter failed to do so. Guinea pigs also developed blood eosinophilia after continuous exposure to the excretory and secretory products of the young adult worms, administered by the mini-pump. Eosinophil responses to WWE could be induced both in athymic CD-1 (ICR) nude mice and in its heterozygous litter mates, suggesting that T cell-independent mechanism(s) could be involved in the induction of blood eosinophilia in the nonpermissive, mouse host. These data clearly indicate that the eosinophilia-inducing factor(s) and the mechanism of eosinophilia are different in permissive and nonpermissive hosts.