Demographics of the semi-slug Parmarion martensi, an intermediate host for Angiostrongylus cantonensis in Hawai'i, during laboratory rearing.

The semi-slug, Parmarion martensi, is an intermediate host of the zoonotic nematode, Angiostrongylus cantonensis, the aetiological agent of neuroangiostrongyliasis or rat lungworm disease in humans. Rearing methods were developed for P. martensi to facilitate studies on nematode transmission and control. Parmarion martensi exhibited high survivorship when reared on a diet of dog food and fresh fruits and vegetables in temperature-controlled cabinets at 21.4°C, 98% relative humidity and 12:12 L:D cycle. Rearing containers were lined with moist paper towels for substrate and plastic pots were provided for hiding/resting and egg-laying. Under these conditions, time to first reproduction was 165.3 ± 12.3 days, fecundity was approximately 34.5 ± 7.8 eggs per adult, and hatch rate was 52.7 ± 3.2%. Survivorship post egg hatch was 86.2 ± 2.9% at 30 days (neonates had a mortality rate of about 14%) and 99% thereafter for up to a year. The demographics of laboratory-reared and wild-caught P. martensi were similar except for the weight of reproductive adults, which was significantly higher in laboratory-reared adults (4.0 ± 0.2 g) than in field-collected adults (1.5 ± 0.1 g).

Albendazole-Schisandrin B Co-Therapy on Angiostrongylus cantonensis-Induced Meningoencephalitis in Mice.

Abstract: Currently, Angiostrongylus cantonensis infections are predominantly treated with albendazole. However, the use of albendazole can provoke certain neurological symptoms as a result of the immune response triggered by the dead worms. Therefore, treatment usually involves co-administration of corticosteroids to limit the inflammatory reaction. Corticosteroids play a useful role in suppressing inflammation in the brain; however, long-term usage or high dosage may make it problematic.Schisandrin B, an active ingredient from Schisandra chinensis, has been shown to have anti-inflammatory effects on the brain. This study aimed to investigate the effects and potential of schisandrin B in combination with albendazole to treat Angiostrongylus-induced meningoencephalitis. Here, we show that albendazole-schisandrin B co-treatment suppressed neuroinflammation in Angiostrongylus-infected mice and increased the survival of the mice. Accordingly, albendazole-schisandrin B co-treatment significantly inhibited inflammasome activation, pyroptosis, and apoptosis. The sensorimotor functions of the mice were also repaired after albendazole-schisandrin B treatment. Immune response was shown to shift from Th2 to Th1, which reduces inflammation and enhances immunity against A. cantonensis. Collectively, our study showed that albendazole-schisandrin B co-therapy may be used as an encouraging treatment for Angiostrongylus-induced meningoencephalitis.

El riesgo de parasitismo por Angiostrongylus cantonensis: una problemática reemergente en Cuba / The risk of parasitism by Angiostrongylus cantonensis: a re-emerging problem in Cuba / O risco de parasitismo devido a Angiostrongylus cantonensis: um problema reemergente em Cuba

RESUMEN Introducción: El riesgo de parasitismo por Angiostrongylus cantonensis transmitido por el caracol gigante africano es una problemática reemergente en Cuba. Objetivo: Sistematizar contenidos esenciales relacionados con el caracol gigante africano y el parásito Angiostrongylus cantonensis, el riesgo de meningitis eosinofílica y su manejo. Método: En el Hospital General Docente "Dr. Agostinho Neto", entre septiembre y diciembre de 2019 se hizo una revisión narrativa sobre el tema a través de una búsqueda en bases de datos electrónicas (Biblioteca Virtual en Salud): LILACS, PubMed, SciELO, RedALyC, Scopus, Cochrane. Resultados: La información se estructuró en caracterización del caracol gigante africano y el riesgo de infección por Angiostrongylus cantonensis en Cuba, patogénesis y epidemiologia de la angiostrongylosis, y diagnóstico y tratamiento de la meningitis eosinofílica por este nemátodo. Se identificaron controversias sobre los criterios diagnósticos, el protocolo de actuación para su prevención y rehabilitación, y la carencia de un instrumento para estratificar el riesgo de esta infección. Conclusiones: Se sistematizaron contenidos esenciales sobre el caracol gigante africano, lo que posibilita la preparación de los profesionales para incrementar la percepción del riesgo de infección por Angiostrongylus cantonensis en la población.

ABSTRACT Introduction: The risk of parasitism by Angiostrongylus cantonensis transmitted by the giant African land snail, Lissachatina fulica is a re-emerging problem in Cuba. Objective: Systematize essential contents related to the giant African land snail and the parasite Angiostrongylus cantonensis, the risk of eosinophilic meningitis and its management. Method: A narrative review was made on the subject in the Teaching General Hospital "Dr. Agostinho Neto", between September and December 2019 through a search in electronic databases (Virtual Health Library): LILACS, PubMed, SciELO, RedALyC, Scopus, Cochrane. Results: The information was structured in the characterization of the African giant land snail and the risk of infection by Angiostrongylus cantonensis in Cuba, pathogenesis and epidemiology of angiostrongylosis, and diagnosis and treatment of eosinophilic meningitis by this nematode. Controversies were identified regarding the diagnostic criteria, the protocol of action for its prevention and rehabilitation, and the lack of an instrument to stratify the risk of this infection. Conclusions: Essential content on the giant African land snail was systematized, enabling the preparation of professionals to increase the perception of the risk of infection by Angiostrongylus cantonensis in the population.

RESUMO Introdução: O risco de parasitismo causado por Angiostrongylus cantonensis transmitido pelo caracol gigante africano é um problema reemergente em Cuba. Objetivo: Sistematizar conteúdos essenciais relacionados ao caracol gigante africano e ao parasita Angiostrongylus cantonensis, ao risco de meningite eosinofílica e seu manejo. Método: No Hospital Geral de Ensino "Dr. Agostinho Neto", entre setembro e dezembro de 2019, foi realizada uma revisão narrativa do assunto através de uma busca em bases de dados eletrônicas (Biblioteca Virtual em Saúde): LILACS, PubMed, SciELO, RedALyC, Scopus, Cochrane. Resultados: As informações foram estruturadas na caracterização do caracol gigante africano e no risco de infecção por Angiostrongylus cantonensis em Cuba, patogênese e epidemiologia da angiostrongilose, diagnóstico e tratamento da meningite eosinofílica por esse nematóide. Foram identificadas controvérsias sobre os critérios diagnósticos, o protocolo de ação para sua prevenção e reabilitação e a falta de um instrumento para estratificar o risco dessa infecção. Conclusões: Foram sistematizados conteúdos essenciais sobre o caracol gigante africano, o que possibilita a preparação de profissionais para aumentar a percepção do risco de infecção por Angiostrongylus cantonensis na população.

Proteomic analysis of excretory-secretory products from young adults of Angiostrongylus cantonensis

BACKGROUND Angiostrongyliasis is caused by the nematode Angiostrongylus cantonensis and can lead to eosinophilic meningitis and meningoencephalitis in humans. The young adult worms play central pathogenic roles in the central nervous system (CNS); however, the underlying mechanism is unclear. Excretory-secretory products (ESPs) are good investigation targets for studying the relationship between a host and its parasite. OBJECTIVES We aimed to profile, identify, and characterise the proteins in the ESPs of A. cantonensis young adults. METHODS The ESPs of young adult worms were collected from culture medium after incubation ranging from 24 to 96 h. Proteomic and bioinformatics analyses were performed to characterise the ESPs. FINDINGS A total of 51 spots were identified, and the highly expressed proteins included two protein disulphide isomerases, one calreticulin, and three uncharacterised proteins. Subsequently, approximately 254 proteins were identified in the ESPs of A. cantonensis young adults via liquid chromatography-mass spectrometry (LC-MS/MS) analysis, and these were further classified according to their characteristics and biological functions. Finally, we identified the immunoreactive proteins from a reference map of ESPs from A. cantonensis young adults. Approximately eight proteins were identified, including a protein disulphide isomerase, a putative aspartic protease, annexin, and five uncharacterised proteins. The study established and identified protein reference maps for the ESPs of A. cantonensis young adults. MAIN CONCLUSIONS The identified proteins may be potential targets for the development of diagnostic or therapeutic agents for human angiostrongyliasis.

Neuroangiostrongyliasis: The "Subarachnoid Phase" and Its Implications for Anthelminthic Therapy.

Infection with the Rat Lungworm Angiostrongylus cantonensis is the leading cause of human eosinophilic meningoencephalitis worldwide. From its origins in southeastern Asia, the parasite was spread extensively throughout the twentieth century and is now established in many of the world's warmer regions. Its clinical effects range from mild and transient symptoms, usually headache with peripheral nerve dysfunction, to severe and permanent central nervous system (CNS) damage, occasionally fatal. The severity and prognosis of disease are determined by the larval dose, acquired by ingesting infected intermediate hosts (slugs and snails) or, less often, paratenic hosts, such as crabs, shrimps, frogs, and monitor lizards. Early diagnosis is critical for treatment and depends on clinical suspicion, for laboratory confirmation from blood and cerebrospinal fluid can be delayed and unreliable. Treatment is fraught with difficulty, compounded by conflicting published results. Corticosteroids play a useful role in suppressing early CNS inflammation, but their duration for maintenance becomes problematic in severe infections. Because most of the pathogenesis results from host immuno-inflammatory responses to migrating and dead larvae in the CNS, anthelminthic therapy remains controversial: if effective, it kills viable larvae, arresting them in the CNS and so exacerbating the pathology. In human infections, it is now clear that many larvae do leave the CNS and reach the pulmonary arteries, sometimes with clinical consequences. Pioneering life-cycle studies in rats demonstrated a "subarachnoid phase" in larval development and migration; recent autopsy findings, outlined here, show it also occurs in humans and has some bearing on treatment. One new and four previously reported cases of human infection are analyzed here, with findings indicating that anthelminthic treatment is effective only when given early and should not be commenced beyond 3 weeks after exposure to infection. In endemic areas, treatment should start as soon as this infection is suspected, even without a clear history of exposure, given the unacceptable risks of waiting for diagnostic laboratory confirmation.

First provincial survey of Angiostrongylus cantonensis in Guangdong Province, China.

The rat lungworm Angiostrongylus cantonensis is a zoonotic nematode with a wide distribution. We report the first provincial survey of the prevalence of A. cantonensis infection among wild rodents and snails in Guangdong Province, China. A total of 2929 Pomacea canaliculata and 1354 Achatina fulica were collected from fields in 22 survey sites with a larval infection rates ranging from 0-26.6% to 0-45.4%. In addition, 114 Cipangopaludina sp and 252 Bellamya sp were bought from markets; larvae were found only in Bellamya snails from two survey sites with an infection rate of 1.4% (1/70) and 3.3% (3/91), respectively. Four hundred and ninety-one rodents were captured in nine sites (Rattus norvegicus, R. flavipectus, Suncus murinus, Mus musculus, Bandicota indica, R. losea and R. rattus). Adult worms were found in R. norvegicus, R. flavipectus and Bandicota indica. Our survey revealed a wide distribution of A. cantonensis and its intermediate hosts P. canaliculata and A. fulica in Guangdong. The prevalence of A. cantonensis in wild snails and rats poses a substantial risk for angiostrongyliasis in humans.

Meningoencefalitis Eosinofílica / Eosinophilic Meningoencephalitis

El Angiostrongylus cantonensis es la causa infecciosa más frecuente de meningoencefalitis eosinofílica en el niño en nuestro medio. El huésped definitivo de este nemátodo es la rata y los humanos se infectan por la ingestión de larvas en tercer estadio presentes en huéspedes intermediarios como caracoles terrestres, transportadores como camarones y algunos peces que se ingieren crudos o mal cocinados o en productos vegetales frescos, contaminados por las secreciones de los caracoles. Las larvas ingeridas penetran en los vasos intestinales hasta llegar a las meninges, donde mueren al cabo de poco tiempo y producen una reacción eosinofílica que se manifiesta como meningitis aséptica. De las al menos 20 especies descritas de Angiostrongylus, solo dos afectan al hombre: el nemátodo Angiostrongylus cantonensis, el gusano del pulmón de la rata, es la causa más frecuente de meningitis eosinofílica. Angiostrongylus (Parastrongylus) costaricensis es el agente causal de la angiostrongyliasis abdominal, o intestinal. Se hace una descripción de los síntomas clínicos de la meningitis eosinofílica, causados por la presencia de las larvas en el cerebro y por las reacciones locales del hospedero. En muchas ocasiones los pacientes se pueden recuperar, pero en algunos casos la evolución puede ser fatal, sobre todo en las infecciones masivas.Se hace referencia a las características epidemiológicas de la enfermedad, el diagnóstico y el tratamiento. Se presenta un caso, diagnosticado en el servicio Miscelánea H de nuestro hospital.

The Angiostrongylus cantonensis is the most frequent infectious cause of eosinophilic meningoencephalitis in children in our settings. The definitive host of this nematode is the rat and the humans get infected by ingesting larvae in the third stage that are present in intermediate hosts like snails, carriers like shrimps and several fish that are eaten raw or bad cooked, or in fresh vegetables contaminated by the secretions of the snails. The ingested larvae enter in to the intestinal vases until they arrive to the meninges, where they die soon, producing an eosinophilic reaction, manifested as aseptic meningitis. From the at least 20 species of Angiostrongylus described, only two affect humans. The nematode Angiostrongylus cantonensis , the worm of the rat lung, is the most frequent cause of the eosinophilic meningitis. The Angiostrongylus (Parastrongylus) costaricensis is the causal agent of the abdominal or intestinal angiostrongyliasis. We describe the clinical symptoms of the eosinophilic meningitis, caused by the presence of larvae in the brain and by the local reactions of the host. In many cases, the patient can recover, but in some cases the evolution can be fatal, especially when the infection is massive.

Meningoencefalitis Eosinofílica / Eosinophilic Meningoencephalitis

El Angiostrongylus cantonensis es la causa infecciosa más frecuente de meningoencefalitis eosinofílica en el niño en nuestro medio. El huésped definitivo de este nemátodo es la rata y los humanos se infectan por la ingestión de larvas en tercer estadio presentes en huéspedes intermediarios como caracoles terrestres, transportadores como camarones y algunos peces que se ingieren crudos o mal cocinados o en productos vegetales frescos, contaminados por las secreciones de los caracoles. Las larvas ingeridas penetran en los vasos intestinales hasta llegar a las meninges, donde mueren al cabo de poco tiempo y producen una reacción eosinofílica que se manifiesta como meningitis aséptica. De las al menos 20 especies descritas de Angiostrongylus, solo dos afectan al hombre: el nemátodo Angiostrongylus cantonensis, el gusano del pulmón de la rata, es la causa más frecuente de meningitis eosinofílica. Angiostrongylus (Parastrongylus) costaricensis es el agente causal de la angiostrongyliasis abdominal, o intestinal. Se hace una descripción de los síntomas clínicos de la meningitis eosinofílica, causados por la presencia de las larvas en el cerebro y por las reacciones locales del hospedero. En muchas ocasiones los pacientes se pueden recuperar, pero en algunos casos la evolución puede ser fatal, sobre todo en las infecciones masivas.Se hace referencia a las características epidemiológicas de la enfermedad, el diagnóstico y el tratamiento. Se presenta un caso, diagnosticado en el servicio Miscelánea H de nuestro hospital(AU)

The Angiostrongylus cantonensis is the most frequent infectious cause of eosinophilic meningoencephalitis in children in our settings. The definitive host of this nematode is the rat and the humans get infected by ingesting larvae in the third stage that are present in intermediate hosts like snails, carriers like shrimps and several fish that are eaten raw or bad cooked, or in fresh vegetables contaminated by the secretions of the snails. The ingested larvae enter in to the intestinal vases until they arrive to the meninges, where they die soon, producing an eosinophilic reaction, manifested as aseptic meningitis. From the at least 20 species of Angiostrongylus described, only two affect humans. The nematode Angiostrongylus cantonensis , the worm of the rat lung, is the most frequent cause of the eosinophilic meningitis. The Angiostrongylus (Parastrongylus) costaricensis is the causal agent of the abdominal or intestinal angiostrongyliasis. We describe the clinical symptoms of the eosinophilic meningitis, caused by the presence of larvae in the brain and by the local reactions of the host. In many cases, the patient can recover, but in some cases the evolution can be fatal, especially when the infection is massive(AU)

Efficacy of curcumin therapy against Angiostrongylus cantonensis-induced eosinophilic meningitis.

Angiostrongylus cantonensis can invade the central nervous system, leading to human eosinophilic meningitis or eosinophilic meningoencephalitis. Curcumin is a natural product which has the effects of anti-inflammation, anti-oxidation and anti-carcinogensis, while the administration of curcumin has been reported to possibly relieve the symptoms of meningitis. The present study tested the potential efficacy of curcumin in A. cantonensis-induced eosinophilic meningitis of BALB/c mice. Assay indicators for the therapeutic effect included the larvicidal effect, eosinophil counts and matrix metalloproteinase-9 (MMP-9) activity in angiostrongyliasis. Eosinophils were mildly reduced in treatment groups compared with infected-untreated mice. However, there were no significant differences in larvicidal effects or MMP-9 activity. This study suggests that anti-inflammatory treatment with curcumin alone has low efficacy, but the treatment does not interfere with MMP-9 expression and is not useful for larvicidal effects. The possible reasons include low curcumin across the blood-brain barrier and also those larvae that survive stimulate MMP-9 production, which promotes blood-brain barrier damage, with leukocytes then crossing the blood-brain barrier to cause meningitis. Further studies will be required to test these possibilities.

Infection of BALB/c mice with Angiostrongylus costaricensis decreases pulmonary inflammatory response to ovalbumin.

SUMMARY The prevalence of asthma in developing countries is lower than in developed countries. Viral, bacterial and parasitic infections may be associated with this discrepancy. The relationship between parasitic infection and asthma prevalence is not clear. Previous controversial data have demonstrated that parasitic infection may either predispose or protect against the development of asthma. The aim of this study is to determine whether infection with Angiostrongylus costaricensis (A. costaricensis) decreases inflammatory lung response to ovalbumin (OVA) in mice. Seven BALB/c mice were infected with A. costaricensis by orogastric gavage (10 larvae/mouse) on day (D) 0. The mice were immunized against OVA by intraperitoneal injection on D 5 and D 12 and received an intranasal OVA challenge (40 micro L) on D 15 and D 17. On D 19 bronchoalveolar lavage (BAL) was performed. Six BALB/c mice (control group) were immunized with OVA using the same protocol, but were not infected with A. costaricensis. Interleukin (IL)-1beta and IL-6 levels were measured in the BAL fluid by using commercial ELISA assays. Total cell counts and differential cell counts were performed in the BAL fluid samples. The group infected with A. costaricensis had lower total cell count in the BAL fluid when compared with the control group (0.11 x 10(6)cells/mL and 0.3 x 10(6)cells/mL, respectively; P = 0.013). BAL fluid IL-1beta levels in the infected group were significantly lower than in the control group (P = 0.008). IL-6 levels in BAL fluid were not different between the groups studied. We conclude that Angiostrongylus costaricensis infection in mice decreases pulmonary inflammatory response to OVA.

Presencia y distribución de hospederos intermediarios de angiostrongylus cantonensis en Camagüey: prevalencia e importancia epidemiológica para su control / Presence and distribution of intermediary hosts Angiostrongylus cantonensis in Camagüey: prevalence and epidemiological importance for its control

La angiostrongilosis ha ganado relevancia epidemiológica en Cuba, atendiendo al número de casos que se reportan, fundamentalmente en la población infantil. El estudio se realizó en el municipio cabecera de Camagüey, el cual se estratificó en 10 zonas para facilitar el estudio. Más del 60 por ciento de los moluscos colectados vivos, pertenecientes a cuatro especies fueron encontradas infestadas de forma natural con larvas de Angiostrongylus cantonensis (Chen, 1935), destacándose Subulina octona (molusco terrestre) con el 81.25 por ciento y Pomacea paludosa (molusco dulceacuícola) con un 66,3 por ciento. La distribución del parásito resultó ser amplia, aspecto importante a considerar, pues ello constituye un serio peligro para la salud de la población. Estos datos que son los primeros que se brindan para el territorio de Camagüey, contribuyen a establecer adecuadas estrategias de control de los hospederos de la enfermedad con énfasis en intervenciones educativas(AU)

Report of ezootic Angiostronglyus cantonesis from Jamaica [ABSTRACT]

OBJECTIVE: To study the status of infection with Angiostrongylus cantonensis in wild rats and snails in Jamaica following an outbreak of eosinophilic meningitis amongst tourists. METHODS: One hundred and thirty-one Rattus rattus and 94 R norvegicus were collected, mainly from the eastern portion of Jamaica. The animals were dissected and the heart and pulmonary arteries explored to reveal A cantonensis. Similarly, several species of land snails were collected. A portion of the head/foot was excised, fragmented and placed in separate dishes of digestion fluid (0.01 percent pepsin in 0.7 percent v/v aqeous HCI). Dishes were examined for nematode larvae 4-5 hours and 24 hours post-digestion. A microscopical comparison of larvae with museum specimens confirmed identification. RESULTS: Overall, significantly more R rattus (42.7 percent) than R morvegicus (21.3 percent) were infected (x2=11.28;p<0.0001). Considering only those parishes where 15 or more rats were collected (Hanover, Manchester, St.James, St. Elizabeth, Kingston and St.Andrew, and Portland) the prevalence of rodent infections ranged from 6 to 59 percent. Of three snails and one slug species collected, only Thelidomus asper harboured A cantonensis larvae. This snail was collected from Manchester where the highest prevalence of rodent infections also occurred. CONCLUSIONS: The findings indicate that A cantonensis is present in rats and snails in Jamaica. In the context of reports (1996, 2000) of eosinophilic meningitis on the island, we recommend that public health officials, clinical parasitologists and travel medicine practitioners consider A cantonensis as a causative agent of eosinophilic meningitis in residents and travellers to Jamaica. (AU)

Eosinophilic meningitis. An unusual cause of headache.

Human parasitic infections are uncommon outside the tropical north but common in animals throughout Australia. The rat lung worm, Angiostrongylus cantonensis, can invade the human brain to cause a chronic meningitis with prolonged headache. This condition can be diagnosed by finding a high eosinophil count in cerebrospinal fluid (CFS), the lumbar puncture also provides symptomatic relief. The outcome is usually benign but death has been reported.