Infection by Angiostrongylus cantonensis in both humans and the snail Achatina (Lissachatina) fulica in the city of Macapá, in the Amazon Region of Brazil

In January and February 2019, a malacological survey was conducted in the area surrounding the residence of a 12-year-old child that had contracted cerebral angiostrongyliasis in the municipality of Macapá, capital of the Amapá State, northern Brazil. The serological examination was positive for Angiostrongylus cantonensis infection, the principal etiological agent of this parasitosis. A sample of 54 molluscs was artificially and individually digested for parasitological analysis, containing 38 specimens of Achatina fulica, nine specimens of Bulimulus tenuissimus and seven specimens of Sarasinula linguaeformis. A. fulica was the most abundant mollusc, and the only species infected with A. cantonensis, as well as presenting co-infections with other nematodes. This is the first report of cerebral angiostrongyliasis in the Amazon Region, and the first record of A. fulica infected with A. cantonensis in Amapá. These findings highlight the potential risks of human angiostrongyliasis, and the need to implement public health measures to control the spread of the disease.

Angiostrongylus (Parastrongylus) cantonensis en huéspedes intermediarios y definitivos en Ecuador, 2014-2017 / Angiostrongylus (Parastrongylus) cantonensis on intermediate and definitive hosts in Ecuador, 2014-2017

Resumen Introducción. Angiostrongylus cantonensis es un serio problema de salud pública y está ampliamente distribuido en el país. Cuando el parásito infecta a los caracoles terrestres Achatina, se enquista en su interior y puede infectar accidentalmente a las personas y otros mamíferos. Objetivo. Establecer la distribución geográfica de A. cantonensis en huéspedes intermediarios (Achatina fulica) y definitivos (Rattus spp.) en Ecuador entre el 2014 y el 2017. Materiales y métodos. Se recolectaron 2.908 ejemplares de A. fulica en 16 provincias utilizando el método de captura por unidad de esfuerzo durante 30 minutos. Se capturaron 211 ejemplares de las especies huéspedes, de los cuales 20 eran Rattus rattus y 191 R. norvegicus. Los ejemplares fueron transportados para su análisis al Instituto Nacional de Salud Pública e Investigación en Guayaquil. En los tejidos del caracol se identificaron y se contabilizaron larvas L3 que luego se inocularon en ratas de laboratorio para reproducir el ciclo de vida. En los roedores se disecaron los cerebros, los corazones, las arterias pulmonares y los pulmones, y se identificaron los parásitos por morfología taxonómica. Resultados. De los caracoles recolectados se encontraron 441 positivos para A. cantonensis (15,2 %) y un total de 6.166 larvas L3. En los ejemplaresRattus spp. capturados (211), 77 (36,5 %) estaban infectados con A. cantonensis, con un total de 220 parásitos (larvas L4-L5 y adultos). Conclusiones. Se constató la presencia de A. cantonensis en varias provincias, lo que confirma el carácter endémico de esta zoonosis en el territorio nacional. La presencia de Rattus spp., huésped definitivo del parásito, y de huéspedes intermediarios, indica el potencial zoonótico de esta infección parasitaria.

Abstract Introduction: Angiostrongylus cantonensis is a serious public health problem and is widely distributed in the country. When the parasite infects the snails, it becomes deeply embedded in their interior and accidentally, it can infect people and other mammals. Objective: To establish the geographical distribution of A. cantonensis intermediate hosts (Achatina fulica) and definitive hosts (Rattus spp.) in Ecuador from 2014 to 2017. Materials and methods: We collected 2,908 A. fulica specimens in 16 provinces using the capture method per unit of effort for 30 minutes. We captured 211 hosts of which 20 were Rattus rattus and 191 R. norvegicus. The specimens were transported to the Instituto Nacional de Salud Pública e Investigación in Guayaquil where the larvae L3 were identified and counted in the tissues of the snail, which were then inoculated in laboratory rats to reproduce the life cycle. In the rodents, the brains, hearts, lung arteries and lungs were dissected, and the parasites were identified by taxonomic morphology. Results: Of the snails harvested, 441 were positive for A. cantonensis (15.2%) and a total of 6,166 L3 larvae were found; 77 (36.5%) specimens of Rattus spp., were infected with A. cantonensis and a total of 220 parasites (L4-L5 larvae and adult worms) were collected. Conclusions: We confirmed the presence of A. cantonensis in several provinces, which ratifies the endemic nature of this zoonosis in the national territory. Rattus spp. specimens constitute the definitive hosts of the parasite, which together with the presence of intermediate hosts, indicates the zoonotic potential of this parasitic infection.

Intravitreal Angiostrongylus cantonensis: first case report in South America / Angiostrongylus cantonensis intravítreo: primeiro relato de caso na América do Sul

ABSTRACT This study reports the first case of intravitreal angiostrongyliasis in South America treated with posterior worm removal via pars plana vitrectomy. This was a retrospective, observational case study. Data from medical charts, wide-field digital imaging, ocular ultrasound, and visual evoked potential studies were reviewed. A 20-month-old boy presented with eosinophilic meningitis and right eye exotropia. Polymerase chain reaction analysis of the cerebrospinal fluid showed a positive result for Angiostrongylus cantonensis. Fundus examination revealed a pale optic disc, subretinal tracks, vitreous opacities, peripheral tractional retinal detachment, and a dead worm in the vitreous cavity. The patient underwent pars plana vitrectomy with worm removal. This case report illustrates the first case of intravitreal angiostrongyliasis in South America, possibly related to the uncontrolled spread of an exotic invasive species of snail.

RESUMO O objetivo deste estudo foi relatar o primeiro caso na América do Sul de angiostrongilíase intravítrea tratada com vitrectomia posterior via pars plana e remoção do verme. Este foi um relato de caso observacional. O prontuário médico, sistema de imagem digital de campo amplo, ultrassonografia ocular, e potenciais evocados visuais foram revistos. Um menino de 1 ano e 8 meses de idade manifestou meningite eosinofílica e exotropia olho direito. A análise de PCR do liquor foi positiva para Angiostrongylus cantonensis. O exame de fundo de olho revelou disco óptico pálido, faixas sub-retinianas, opacidades vítreas, descolamento de retina tracional periférico e um verme morto no vítreo. O paciente foi submetido a vitrectomia posterior via pars plana com a remoção do verme. Concluindo, este é o primeiro relato de caso de angiostrongilíase intravítrea na América do Sul, possivelmente relacionado com a disseminação de uma espécie de lesma exótica neste continente.

Prevalence and distribution of angiostrongylus cantonensis (nematoda, angiostrongylidae) in achatina fulica (mollusca, gastropoda) in baixada santista, São Paulo, Brazil

ABSTRACT INTRODUCTION Angiostrongylus cantonensis is causes eosinophilic meningoencephalitis in humans. Worldwide expansion of this nematode is linked to the dispersion of their hosts. This study aimed to determine the prevalence of A. cantonensis infection in Achatina fulica in the nine municipalities that make up Baixada Santista, São Paulo, Brazil. METHODS Angiostrongylus cantonensis larvae were analyzed using optical microscopy. We performed polymerase chain reaction and restriction fragment length polymorphism using restriction endonuclease ClaI, directed to the internal transcribed spacer region 2 of A. cantonensis larval DNA. RESULTS Of the 540 snails analyzed, 117 (21.7%) were infected by A. cantonensis. For morphological and morphometric analyses, 60 larvae were used. Second-stage larvae were, on average, 358.2µm long and 26.4µm wide, while third-stage larvae were, on average, 450µm long and 21.12µm wide. The tails of the larvae ended in a fine tip. CONCLUSIONS All municipalities comprising Baixada Santista had A. fulica that were naturally infected with A. cantonensis. All of the observed characteristics were typical of the species.

Molecular diagnosis of eosinophilic meningitis due to Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) by polymerase chain reaction-DNA sequencing of cerebrospinal fluids of patients

Cerebrospinal fluid (CSF) samples from clinically diagnosed patients with detectable Angiostrongylus canto-nensis-specific antibodies (n = 10), patients with clinically suspected cases that tested negative for A. cantonensis-an-tibodies (n = 5) and patients with cerebral gnathostomiasis (n = 2) and neurocysticercosis (n = 2) were examined by a single-step polymerase chain reaction (PCR) method using the AC primers for the 66-kDa native protein gene. The PCR method detected A. cantonensis DNA in CSF samples from four of 10 serologically confirmed angiostrongyliasis cases. The PCR results were negative for the remaining CSF samples. The nucleotide sequences of three positive CSF-PCR samples shared 98.8-99.2% similarity with the reference sequence of A. cantonensis. These results indicate the potential application of this PCR assay with clinical CSF samples for additional support in the confirmation of eosinophilic meningitis due to A. cantonensis.

Clinical Manifestations of Eosinophilic Meningitis Due to Infection with Angiostrongylus cantonensis in Children

Eosinophilic meningitis, caused by the nematode Angiostrongylus cantonensis, is prevalent in northeastern Thailand, most commonly in adults. Data regarding clinical manifestations of this condition in children is limited and may be different those in adults. A chart review was done on 19 eosinophilic meningitis patients aged less than 15 years in Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Clinical manifestations and outcomes were reported using descriptive statistics. All patients had presented with severe headache. Most patients were males, had fever, nausea or vomiting, stiffness of the neck, and a history of snail ingestion. Six patients had papilledema or cranial nerve palsies. It was shown that the clinical manifestations of eosinophilic meningitis due to A. cantonensis in children are different from those in adult patients. Fever, nausea, vomiting, hepatomegaly, neck stiffness, and cranial nerve palsies were all more common in children than in adults.

Comprehensive Review of Ocular Angiostrongyliasis with Special Reference to Optic Neuritis

Angiostrongyliasis, caused by Angiostrongylus cantonensis infection, is a food-borne parasitic disease. Its larvae evoke eosinophilic inflammation in the central nervous system, but can also cause pathological changes in the eyes. Among ocular angiostrongyliasis cases, the incidence of optic neuritis is low and only few sporadic reports exist. Some patients with optic neuritis developed obvious hypopsia or even vision loss, which would seriously influence the quality of life of patients. Prompt treatment of optic neuritis caused by A. cantonensis is the key factor for minimizing the incidence of serious complications of this disease. In this review, we first provide a comprehensive overview of ocular angiostrongyliasis, and then focus on the clinical features of optic neuritis caused by A. cantonensis.

The first case of Angiostrongylus cantonesis eosinophilic meningitis diagnosed in the city of São Paulo, Brazil

Introduction: Angiostrongylus cantonensis is a natural parasite found in lung arteries of rats, which in humans may cause eosinophilic meningitis. Objective: To report the first case of eosinophilic meningitis caused by Angiostrongylus cantonensis in the city of São Paulo, Brazil. Case report: A male patient, 11 years old, living in the southern area of São Paulo, was admitted to the Pediatric Emergency Department with ongoing headaches for three days, but no fever or any other complaint. The presence of snails and rodents was reported in the peridomicile. The child was awake, lucid, oriented; muscular strength preserved, isochoric, photo reagent pupils and terminal nuchal rigidity - Glasgow Coma Scale (GCS) = 15. The laboratory tests showed a mild leukocytosis with 1736 eosinophils/mm3 and the CSF analysis disclosed 160 leukocytes/mm3 with 36% of eosinophils. The bacterial culture was negative. Computed Cerebral Tomography showed no alterations. The RT-PCR assay for detecting Angiostrongylus cantonensis larvae and DNA was negative. ELISA antibodies for IgG anti-A. cantonensis was negative in serum and undetermined in CSF and samples collected five days after the onset of symptoms. Seroconversion was observed in the sample collected 135 days later. Conclusion: the epidemiological and clinical data, the CSF alterations with eosinophilia and the seroconversion strongly suggest Angiostrongylus cantonensis eosinophilic meningitis.

Introdução: Angiostrongylus cantonensis é um parasito natural das artérias de pulmões de ratos, que pode causar, em humanos, meningite eosinofílica. Objetivo: Relatar o primeiro caso de meningite eosinofílica causado por A. cantonensis na cidade de São Paulo, Brasil. Relato de caso: Paciente do sexo masculino, 11 anos, residente na zona sul de São Paulo, foi admitido no serviço de emergência pediátrica com história de cefaléia há três dias, sem febre ou outras queixas. Relato de presença de moluscos e roedores no peridomicílio. Ao exame físico, criança desperta acianótica, anictérica, hidratada; lúcido, orientado; força muscular preservada, isocórica, pupilas fotorreagentes e rigidez de nuca terminal - Glasgow Coma Scale = 15. Exames laboratoriais indicaram leve leucocitose com 1736 eosinófilos/mm3 e a análise do líquor revelou a presença de 160 leucócitos/mm3 com 36% de eosinófilos. Cultura para bactérias negativa. Tomografia cerebral sem alterações. Pesquisa direta de larvas e de DNA por PCR-RT para Angiostrongylus cantonensis foi negativa. ELISA para anticorpos IgG anti-A. cantonensis negativo no soro e indeterminado no líquor nas amostras coletadas após cinco dias do início dos sintomas. Soroconversão observada na amostra coletada após 135 dias. Conclusão: A história epidemiológica, dados clínicos, alterações liquóricas com presença de eosinofilia e a soroconversão sugerem fortemente o diagnóstico de meningite eosinofílica por A. cantonensis.

Angiostrongylus cantonensis (Nematode: Metastrongyloidea) in molluscs from harbour areas in Brazil

Angiostrongylus cantonensis is the most common aetiological agent of human eosinophilic meningoencephalitis. Following a report indicating the presence of this parasite in Brazil in 2007, the present study was undertaken to investigate the presence of A. cantonensis in the surrounding Brazilian port areas. In total, 30 ports were investigated and the following molluscs were identified: Achatina fulica, Belocaulus sp., Bradybaena similaris sp., Cyclodontina sp., Helix sp., Leptinaria sp., Melampus sp., Melanoides tuberculata, Phyllocaulis sp., Pomacea sp., Pseudoxychona sp., Rhinus sp., Sarasinula marginata, Streptaxis sp., Subulina octona, Succinea sp., Tomigerus sp., Wayampia sp. and specimens belonging to Limacidae and Orthalicinae. Digestion and sedimentation processes were performed and the sediments were examined. DNA was extracted from the obtained larvae and the internal transcribed spacer region 2 was analysed by polymerase chain reaction-restriction fragment length polymorphism after digestion with the endonuclease ClaI. Of the 30 ports investigated in this study, 11 contained molluscs infected with A. cantonensis larvae. The set of infected species consisted of S. octona, S. marginata, A. fulica and B. similaris. A total of 36.6% of the investigated ports were positive for A. cantonensis, indicating a wide distribution of this worm. It remains uncertain when and how A. cantonensis was introduced into South America.

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.

Optic neuritis caused by intraocular angiostrongyliasis.

A 21-year-old Thai man first presented with eosinophilic meningitis. One week later he developed visual impairment of the left eye with a visual acuity of 20/600. He had a Marcus Gunn pupil, constricted visual field, prolongation of visual evoked potential and the presence of inflammatory cells in the vitreous cavity of the affected eye. On funduscopic examination there was disc swelling with hyperemia of the left eye. These ocular findings are compatible with optic neuritis. The causative agent, Angiostrongylus cantonensis, was identified in the vitreous cavity. To our knowledge this is the first case of optic neuritis caused by intraocular angiostrongyliasis. Ten days after administration of corticosteroid his severe headache was resolved, and by 4 weeks the disk swelling of the left eye subsided. Eight months after treatment the visual acuity of the left eye had not improved due to permanent damage to the retinal pigment epithelium caused by the intraocular parasite.

Detection of circulating antibody of Parastrongylus cantonensis in sera with eosinophilic meningitis by dot-blot ELISA.

BACKGROUND: Eosinophilic meningitis caused by Parastrongylus cantonensis, the rat lung worm is a major public health problem in Thailand. Humans acquire this parasite by eating raw food containing infective Parastrongyliasis is dificult to make because identification of parasite materials by biopsy or chance finding is rarely possible. OBJECTIVE: Develop alternative approaches of Parastrongylus cantonensis infection employing crude antigen by dot-blot ELISA. MATERIAL AND METHOD: The investigation was carried out between October 2003 and July 2004 in Khon Kaen, which is an endemic area. One hundred thirty two serum samples from several villagers of the present study area were divided into five groups. Group 1 consisted of 30 patients with Cryptococcal meningitis, group 2 were 22 cases of Bacterial meningitis, group 3 were 32 cases of eosinophilic meningitis, group 4 were other parasitic infections (4 from Cysticercosis, 2 from Fascioliasis, 12 from Malaria), and group 5 were 30 negative healthy control. RESULTS: The result demonstrated that 26 cases of eosinophilic meningitis, were positive with Dot-blot ELISA (81.3%). None of the other groups of sample reacted with this antigen. CONCLUSION: The data obtained showed that Dot-blot ELISA has a potential for diagnosis of eosinophilic meningitis caused by Parastrongylus cantonensis.

First record of molluscs naturally infected with Angiostrongylus cantonensis (Chen, 1935) (Nematoda: Metastrongylidae) in Brazil

Seeking the identification of Angiostrongylus cantonensis as a potential etiological agent of three clinical cases of eosinophilic meningitis, mollusc specimens were collected in the state of Espírito Santo, Brazil. The snails were identified as Sarasinula marginata (45 specimens), Subulina octona (157), Achatina fulica (45) and Bradybaena similaris (23). Larvae obtained were submitted to polymerase chain reaction and restriction fragment length polymorphism diagnosis. Their genetic profile were corresponded to A. cantonensis. Rattus norvegicus experimentally infected with third-stage larvae, developed menigoencephalitis, and parasites became sexually mature in the lungs. Additionally, larvae obtained from A. fulica snails, from São Vicente, state of São Paulo, also showed genetic profiles of this nematode. This is the first record of Brazilian molluscs infected with this nematode species.

Communicating hydrocephalus as a complication of eosinophilic meningoencephalitis.

The authors reported an adult patient with communicating hydrocephalus in eosinophilic meningoencephalitis. He presented with localized peritonitis and then developed eosinophilic meningoencephalitis. Angiostrongylus cantonensis was the causative agent. This was confirmed by the positive serology test. His consciousness did not recover after supportive treatment. The MRI of the brain showed diffuse enlargement of the ventricular system two weeks after the diagnosis was made. The parameters for hydrocephalus were measured and were compatible with the Gyldensted's criteria.

Eosinophilic meningitis due to Angiostrongylus cantonensis.

Angiostrongylus cantonensis is a nematode parasite that inhabits the pulmonary arteries and heart of rodents. It is one of the causative agents of fatal eosinophilic meningoencephalitis in man. We present five cases of eosinophilic meningitis presumably due to infection with Angiostrongylus cantonensis . All the five patients gave history of ingestion of monitor lizard within ten days of onset of symptoms.

Caracterización de antígenos de bajo peso molecular de angiostrongylus costaricensis, reconocidos durante una infección experimental en roedores / Characterization of low molecular weight antigens of angiostrongylus costaricensis recognized during an experimental infection in mice

La respuesta inmune hacia componentes de bajo peso molecular del antígeno somático de A. costaricensis fue investigada en el modelo animal experimental. Durante la fase crónica de la infección y mediante el Western blot, son detectados por la IgG e IgG1 tres antígenos inmunodominantes: uno de 20 otro de 15 y uno de 2 kDa respectivamente. Mediante el método de digestión de Edmann se obtuvo la secuencia de aminoácidos inicial de cada componente: para la banda de 15 kDa una secuencia con un 100 por ciento de homología con la enzima glutation-S-transferasa de Brugia malayi y Onchocerca volvulus, para el componete de 2kDa una secuencia con 95 por ciento de homología con la proteína Ubiquitina, y para el compontente de 20 kDa una secuencia de trece aminoácidos, que no presenta homología con alguna proteína hasta ahora descrita. En general la reacción cruzada contra estos componentes es muy débil y en el caso particular del componente de 20 kDa no se detecta ninguna reacción cruzada. Se proponen futuros estudios con sueros humanos, para verificar la utilidad de dichos antígenos en el desarrollo de una prueba diagnóstica específica para la angiostrongiliosis abdominal.

Clinical manifestations and outcome of patients with severe eosinophilic meningoencephalitis presumably caused by Angiostrongylus cantonensis.

The clinical manifestations and outcome of patients with severe eosinophilic meningoencephalitis has never been reported. We reported 11 comatose patients with eosinophilic meningoencephalitis. Most of them presented with subacute to chronic headache and fever, followed by acute coma. Cerebrospinal fluid abnormalities were similar to alert patients with eosinophilic meningitis. None of them had received antihelmintic drug and seven patients were treated with corticosteroids. Ten patients died and one patient is still in a coma. Corticosteroids seem to be ineffective in severe eosinophilic meningitis.

Jejunal perforation caused by abdominal angiostrongyliasis

The authors describe a case of abdominal angiostrongyliasis in an adult patient presenting acute abdominal pain caused by jejunal perforation. The case was unusual, as this affliction habitually involves the terminal ileum, appendix, cecum or ascending colon. The disease is caused by the nematode Angiostrongylus costaricensis, whose definitive hosts are forest rodents while snails and slugs are its intermediate hosts. Infection in humans is accidental and occurs via the ingestion of snail or slug mucoid secretions found on vegetables, or by direct contact with the mucus. Abdominal angiostrongyliasis is clinically characterized by prolonged fever, anorexia, abdominal pain in the right-lower quadrant, and peripheral blood eosinophilia. Although usually of a benign nature, its course may evolve to more complicated forms such as intestinal obstruction or perforation likely to require a surgical approach. Currently, no efficient medication for the treatment of abdominal angiostrongyliasis is known to be available. In this study, the authors provide a review on the subject, considering its etiopathogeny, clinical picture, diagnosis and treatment