Progress of researches on techniques for detection of Angiostrongylus cantonensis in intermediate host snails / 中国血吸虫病防治杂志

Angiostrongyliasis cantonensis is an emerging infectious disease in China. Snails are intermediate hosts of Angiostrongylus cantonensis and play a critical role in the transmission of angiostrongyliasis cantonensis. Detection of A. cantonensis in snails is an important part of epidemiological surveys. Currently, the rapid developments in the techniques for detection of A. cantonensis in snails facilitate the surveillance of angiostrongyliasis cantonensis and provide an important support for angiostrongyliasis cantonensis prevention and control. This review summarizes the advances in the techniques for detection of A. cantonensis in snails.

Prevalence of Angiostrongylus cantonensis infection in snails in Fujian Province from 2017 to 2021 / 中国血吸虫病防治杂志

Objective To investigate the prevalence of Angiostrongylus cantonensis infection in market-sold and field-captured snails in Fujian Province, so as to provide the scientific basis for the formulation of the angiostrongyliasis control measures. Methods In each month from May to October during the period from 2017 through 2021, Pomacea snails were collected from two field fixed surveillance sites and Bellamya aeruginosa collected from one agricultural product market in Fuzhou City, while Pomacea and B. aeruginosa snails were collected from two agricultural product markets and four restaurants in Xiamen City. At least 50 Pomacea snails and 500 g B. aeruginosa were sampled each time. A. cantonensis infection was detected in Pomacea snails using lung microscopy, and in B. aeruginosa using a tissue homogenate method. Results A total of 9 531 Pomacea snails were detected for A. cantonensis infection in two cities of Fuzhou and Xiamen, and the overall prevalence of A. cantonensis infection was 4.40%, with the highest prevalence in 2017 (6.82%, 116/1 701) and the lowest prevalence in 2019 (3.46%, 83/2 400). The prevalence of A. cantonensis infection was significantly higher in Pomacea snails sampled from Fuzhou City (11.23%, 326/2 903) than from Xiamen City (1.40%, 93/6 628) (χ2 = 461.48, P < 0.01). A. cantonensis larvae were detected in larval Pomacea snails in two cities of Fuzhou and Xiamen each month. The prevalence of A. cantonensis infection in Pomacea snails appeared an overall tendency towards a rise with month in Fuzhou City, with the highest prevalence in October (15.24%), and there was a significant difference among month (χ2 = 14.56, P < 0.05), while the prevalence of A. cantonensis infection in Pomacea snails was low in Pomacea snails sampled from Xiamen City each month, with the highest prevalence in June (2.64%), and there was a significant difference among month (χ2 = 23.17, P < 0.05). A total of 18 966 B. aeruginosa snails were detected for A. cantonensis infection in two cities of Fuzhou and Xiamen, and the overall prevalence of A. cantonensis infection was 0.01%. Conclusions A. cantonensis infection was identified in Pomacea and B. aeruginosa snails in Fujian Province from 2017 to 2021, and there is a potential risk of human A. cantonensis infection.

Progress of researches on the role and mechanisms of non - coding RNA in Angiostrongylus cantonensis infection / 中国血吸虫病防治杂志

Angiostrongylus cantonensis is a food-borne zoonotic parasite, and human infection may cause eosinophilic meningitis. Non-coding RNAs (ncRNAs) may regulate physiological and pathological processes at multiple biological levels; however, there are few studies pertaining to the regulatory role of ncRNAs in A. cantonensis infection. Based on publications retrieved from PubMed, Wanfang Data and CNKI, the regulatory role of ncRNAs in A. cantonensis infections mainly includes immune responses, cell apoptosis and signaling transduction, and ncRNAs may serve as biomarkers for diagnosis of angiostrongyliasis. This review summarizes the main roles of ncRNAs in A. cantonensis infections and the underlying mechanisms, so as to provide insights into diagnosis and treatment of angiostrongyliasis.

Population survey of Pomacea spp. in Shandong Province and preliminary study on the risk of population infection with Angiostrongylus cantonensis / 中华地方病学杂志

Objective:To study the population distribution of Pomacea spp. in Shandong Province and the risk of angiostrongyliasis cantonensis in the local population, and to provide a basis for scientific prevention and control of related diseases. Methods:From July to December 2021, Yanzhou District of Jining City, Ningyang County of Taian City, and Dongying District of Dongying City were selected as surveillance sites to investigate the population and distribution range of Pomacea spp., live snail samples were collected for morphological and genetic identification, and Pomacea spp. infected with the larva of Angiostrongylus cantonensis was detected by lung test. At the same time, sentinel hospital case surveillance was carried out in Yanzhou District, Jining City, and questionnaire was used to study the local residents' awareness of angiostrongyliasis cantonensis and their personal health behaviors. Results:A total of 312 live snail samples were collected. After morphological identification, they were all Pomacea spp.. After gene sequencing, two populations of Pomacea canaliculata and Pomacea maculata were found. No positive snails infected with Angiostrongylus cantonensis were found. A total of 126 patients with headache as the main neurological symptom were admitted to the sentinel hospital, but there were no monitoring cases that met the inclusion criteria. Among the survey population, 48.38% (134/277) of the respondents had heard of angiostrongyliasis cantonensis, 44.77% (124/277) knew that eating Margarya melanioides might cause angiostrongyliasis cantonensis, and 83.39% (231/277) had no related unhealthy eating behavior. Conclusion:Pomacea spp. is found and reported for the first time in Shandong Province, and there is a risk of population infection with angiostrongyliasis cantonensis.

Conocimientos, percepciones y prácticas de médicos de atención primaria en Ecuador sobre la infección por Angiostrongylus cantonensis / Knowledge, perceptions and practice of primary healthcare doctors in Ecuador on Angiostrongylus cantonensis infection

Introducción: La angiostrongiliasis humana presenta un amplio espectro clínico: desde una infección asintomática a meningitis eosinofílica, meningoencefalitis eosinofílica y angiostrongiliasis ocular. Objetivo: Determinar los conocimientos, percepciones y prácticas en relación con la infección por Angiostrongylus cantonensis que poseen médicos de atención primaria de la República del Ecuador. Métodos: Se realizó un estudio observacional descriptivo. Se diseñó, validó y aplicó una encuesta sobre conocimientos, percepciones y prácticas a 163 médicos de atención primaria de las provincias Napo y Guayas, entre los meses de noviembre y diciembre de 2017. La información obtenida se almacenó en una base de datos Microsoft Access y se realizó un análisis de frecuencias a las respuestas dadas a cada una de las preguntas. Resultados: Se encontraron conocimientos insuficientes, percepciones inadecuadas y prácticas incorrectas en relación con la angiostrongiliasis. Conclusiones: Estos resultados orientan hacia la implementación de un programa de intervención educativa en médicos de atención primaria con el fin de atenuar las deficiencias encontradas, para incidir de forma positiva en comunidades donde existe la presencia de hospederos intermediarios y definitivos infectados y un riesgo potencial de infección.

Introduction: Human angiostrongyliasis presents a broad clinical spectrum, which ranges from asymptomatic infection to eosinophilic meningitis, eosinophilic meningoencephalitis, and ocular angiostrongyliasis. Objective: To determine the knowledge, perceptions, and practice of primary healthcare doctors in the Republic of Ecuador regarding Angiostrongylus cantonensis infection. Methods: It was conducted a descriptive observational study. A survey on knowledge, perceptions, and practice was designed, validated, and applied to 163 primary healthcare doctors from Napo and Guayas provinces between November and December 2017. The information obtained was stored in a Microsoft Access 2016 database, and a frequency analysis was performed to the answers provided to every question. Results: Insufficient knowledge, inadequate perceptions, and incorrect practice regarding angiostrongyliasis were found. Conclusions: The results evidenced the need to implement an educational intervention program to primary healthcare doctors aimed at reducing the deficiencies found to have a positive impact on the communities where the intermediate and definitive hosts and a potential infection risk exist.

Eosinophilic meningitis due to A. Cantonensis revealed at autopsy

Parasitic infection of the central nervous system could be fatal, and its incidence is rising due to increasing worldwide travel. Amongst the various nematodes, Angiostrongylus contonensis is the commonest and causes eosinophilic meningitis. It is a zoonotic disease produced due to the ingestion of raw or undercooked snails or slugs. Most cases of angiostrongyliasis are mild and self-limiting, but death can occur in severe cases lacking timely and proper treatment. Very few autopsy cases of A. cantonensis are reported. We present the case of a 32-year-old mentally challenged orphan male with eosinophilic meningitis at autopsy.

Detection of antigens in paraffin sections of worms and snails infected by Angiostrongylus cantonensis by immunofluorescence reaction / Detecção de antígenos em cortes parafinados de vermes e caramujos infectados por Angiostrongylus cantonensis pela reação de imunofluorescência

The Indirect Immunofluorescence Assay (IFA) was used to identify stage-specific antigenic structures in paraffin sections of female larvae and worms and snails tissues, infected with third stage larvae of Angiostrongylus cantonensis. Sera from eosinophilic meningitis cases were used to assess reactivity. Non-reactive sera from patients with other parasitic diseases and from individuals without other etiologies were used as controls for cross-reactivity. Larvae and worms showed high reactivity to IgG antibodies. IgM antibodies reacted with low intensity only to larvae. Fluorescent reactions were observed in the cuticles and internal structures on worms sections, with a marked reaction in the uterus content. In the snail tissues, the larvae were found exclusively inside the granulomas, with fluorescent markings in the cuticles of the larvae and inside the granulomatous tissues. This fluorescent pattern suggests the presence of excretory/secretory antigens distributed throughout the granulomas. Expressive cross-reactivity occurred in sera from patients with other parasitic diseases, especially strongyloidiasis. The use of IFA applied to paraffin sections to identify structures with antigenic potential and the study of new serological markers, can contribute to the improvement of the laboratory diagnosis of eosinophilic meningitis. (AU)

A Reação de Imunofluorescência Indireta (RIFI) foi utilizada para localizar antígenos em estruturas estágio-específicas em cortes parafinados de vermes fêmeas e em tecidos de caramujos do Gênero Biomphalaria infectados com larvas de terceiro estágio de Angiostrongylus cantonensis. Soros de casos confirmados de meningite eosinfílica foram usados para avaliação da reatividade. Soros não reagentes de casos suspeitos; de pacientes com outras parasitoses e de indivíduos sem outras etiologias foram utilizados como controle de reatividade cruzada. Anticorpos da classe IgG foram reativos para antígenos presentes nos dois estágios e, anticorpos IgM somente para o estágio larvário. Nos cortes de vermes, as marcações fluorescentes foram assinaladas nas cutículas e estruturas internas, com acentuada marcação para os conteúdos uterinos. Nos tecidos dos caramujos as larvas foram encontradas exclusivamente no interior dos granulomas, com marcações fluorescentes nas cutículas das larvas e no interior dos tecidos granulomatosos. O padrão de fluorescência no granuloma sugere a marcação de antígenos excretores/secretores. Reatividade cruzada mais expressiva ocorreu com anticorpos presentes em soros de pacientes com outras parasitoses, com destaque para estrongiloidíase. A RIFI em cortes parafinados abre novas perspectivas para identificação de antígenos e de marcadores sorológicos, que possam ser aplicados no aprimoramento do diagnóstico laboratorial da meningite eosinofílica. (AU)

Immunoanalysis of different antigenic preparations of Angiostrongylus cantonensis for neuroangiostrongyliasis diagnosis improvement

BACKGROUND Angiostrongylus cantonensis is the etiological agent of neuroangiostrongyliasis in humans, which is developed in gastropods and vertebrate species, mainly rodents. Human transmission occurs through consumption of molluscs and paratenic hosts infected with L3, and the migration of larvae to the central nervous system causes eosinophilic meningitis. Laboratory diagnosis is based on molecular and immunological tests, using young or adult females as a source of antigens. However, these tests give positive results only after several weeks of symptoms onset and also cross-reactions with others parasite infections may occur. OBJECTIVES The purpose of this work was to study different antigenic preparations of distinct evolutionary phases of A. cantonensis, in order to improve serological techniques for disease immunodiagnosis. METHODS For this purpose, antigenic fractions of different evolutionary forms were evaluated by Dot-enzyme-linked immunosorbent assay (Dot-ELISA) and Western blot using serum samples. FINDINGS All analysed fractions showed reactivity with serum samples from patients with neuroangiostrongyliasis, especially female membrane alkaline (FAM) and female soluble alkaline (FAS) fractions together with female soluble saline (FSS), improving the technique specificity. MAIN CONCLUSIONS The results point to the possibility of use of raw female antigens in association with alkaline membrane antigens extracted from adult worms to aid in diagnosis and helps initiate neuroangiostrongyliasis surveillance and control actions.

Angiostrongylus cantonensis en Achatina fulica en la provincia del Napo, Ecuador y el riesgo incrementado de angiostrongiliasis / Angiostrongylus cantonensis in Achatina fulica in Napo province, Ecuador and the increased risk of angiostrongyliasis

Introducción: Angiostrongylus cantonensis es reconocido como uno de los principales patógenos causantes de la meningoencefalitis eosinofílica, fue identificado en Ecuador por primera vez en 2008. Métodos: se recolectaron 1476 ejemplares de Achatina fulica con el método de captura por unidad de esfuerzo durante 30 minutos, en 3 cantones de la provincia del Napo, con el fin de establecer la prevalencia de infección por A. cantonensis Resultados: el porcentaje total de caracoles infectados fue de 46,5% (687/1476). Conclusiones: Los resultados revelan una amplia distribución de A. fulica infectado con A. cantonensis, lo que, sumado a la gran cantidad de hospederos definitivos presentes, indica que un número considerable de personas tiene riesgo de adquirir angiostrongiliasis. Se necesita intervenciones educativas comunitaria orientadas a formación sanitaria, recalcando el riesgo de adquirir la infección parasitaria, principalmente por el consumo de A. fulica, crudos y/o con cocción inadecuada, principal forma de contagio. Además, se recomienda vigilancia rigurosa y control de los hospedadores involucrados, saneamiento ambiental, haciendo insistencia en factores relacionados con los hábitos biológico del caracol gigante africano, entre ello alimentos (vegetales), suelos y derivados del caracol de uso artesanal; para prevenir la aparición de casos esporádicos y de brotes de la enfermedad(AU)

Introduction: Angiostrongylus cantonensis is recognized as one of the main pathogens that cause eosinophilic meningoencephalitis, it was identified in Ecuador for the first time in 2008. Methods: 1476 specimens of Achatina fulica were collected using the capture method per unit of effort for 30 minutes, in 3 cantons of the Napo province, in order to establish the prevalence of infection by A. cantonensis Results: the total percentage of infected snails was 46.5% (687/1476). Conclusions: The results reveal a wide distribution of A. fulica infected with A. cantonensis, which, added to the large number of definitive hosts present, indicates that a considerable number of people are at risk of acquiring angiostrongyliasis. Community educational interventions aimed at health training are needed, emphasizing the risk of acquiring parasitic infection, mainly due to the consumption of A. fulica, raw and/or inadequately cooked, the main form of contagion. In addition, rigorous surveillance and control of the hosts involved, environmental sanitation, insisting on factors related to the biological habits of the giant African snail, including food (vegetables), soil and snail derivatives for artisanal use; to prevent the appearance of sporadic cases and outbreaks of the disease(AU)

A comparative study of lung-microscopy and tissue homogenate in detecting Angiostrongylus cantonensis in the Pomacea canaliculata / 中国热带医学

@#Abstract: Objective　To compare the efficiency of lung-microscopy and tissue homogenate in the detection of Angiostrongylus cantonensis larvae from Pomacea canaliculate, with the amin of finding a simple and rapid method suitable for different scenarios. Methods　Pomacea canaliculata was caught and collected from ponds, ditches, rivers and other environments in the confirmed epidemic areas reported by predecessors. After each snail was weighed one by one, and dissected into two parts: lung sac and muscle. Firstly, each snail lung sac was check for nodules with lung-microscopy, and the nodules were picked out with anatomical needle and press them separately. Then, the worm was found and identified for worm species under microscope, and the lung sac and snail meat then was rechecked with tissue homogenate. Results　A total of 330 snails were detected, with 19.1% (63/330) snails with Angiostrongylus cantonensis stage Ⅲ larvae were detected by tissue homogenate and 15.8% (52/330) snails with nodules were detected by lung-microscopy. Among them, 36 snails with nodules and larvae were detected by the lung-microscopy, and all of them were positive by the tissue homogenate, with a coincidence rate of 100% (36/36); 16 snails with nodules but no larvae, among which 6 snails were positive and 10 snails were negative by the tissue homogenate, The false detection rate was 19.2% (10/52). 278 snails with no nodules, but 21 of them were detected by the tissue homogenate, the missing rate was 7.6% (21/278). There was no significant difference between tissue homogenate and lung-microscopy (taking the positive determination of nodules as the standard) (χ2=1.27, P=0.26, P>0.05). There was significant difference between tissue homogenate and lung-microscopy (taking the detection of larvae as the standard)(χ2=8.66, P = 0.003, P<0.01). There was no significant difference between the two methods and tissue homogenate in the detection rate of large snails ( ≥25 g, χ2=0.08，P=0.777; χ2=2.58, P=0.108), but there was significant difference between the two methods and tissue homogenate in the detection rate of small snail (≤10 g, χ2=5.63, P=0.02). Conclusions　Compared with the tissue homogenate, lung-microscopy is simple in the detection of large snails, requires less instruments and equipment, and its detection speed is faster. It is suitable for the field investigation of the natural focus of Angiostrongylus cantonensis. The tissue homogenate has high sensitivity, can directly display the insect state and activity, has strong insect vitality and high detection rate, it's more suitable for food safety risk monitoring.

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.

Evidencias clínico-epidemiológicas vinculadas a Lissachatina fulica en un adulto con meningoencefalitis eosinofílica causada por Angiostrongylus cantonensis / Clinical-epidemiological evidence related to Lissachatina fulica in an adult with eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis

Introducción: El helminto Angiostrongylus cantonensis es un parásito habitual en los pulmones de la rata y puede ocasionar meningoencefalitis eosinofílica en el hombre cuando se pone en contacto con las larvas por ingestión accidental. En Cuba es endémico y el riesgo de contraerlo aumenta con la entrada del caracol gigante africano en el país. Objetivo: Describir las acciones desarrolladas por las autoridades sanitarias locales para el control del caracol gigante africano entre 2016 y 2018 y la aparición de un paciente en 2018 con meningoencefalitis eosinofílica causada por Angiostrongylus cantonensis vinculado epidemiológicamente con la presencia de este caracol. Métodos: Se realizó un estudio cualitativo a partir de un grupo focal con el que se trabajó ante la aparición del caracol gigante africano en un área de salud del municipio San Miguel del Padrón. Se realiza una encuesta semi-estructurada. Resultados: Se trazaron las estrategias para la erradicación de la especie invasora a partir de un trabajo comunitario. Dos años después, se observa nuevamente el caracol gigante africano y un paciente con meningoencefalitis eosinofílica epidemiológicamente asociado a Angiostrongylus cantonensis. Conclusiones: Las acciones realizadas entre 2016 y 2018 resultaron ser insuficientes por el nuevo avistamiento del caracol en el área, con el agravante de encontrar un paciente con meningoencefalitis eosinofílica epidemiológicamente asociado con el molusco(AU)

Introduction: Helmint Angiostrongylus cantonensis is a natural parasite in the lungs of ratas. Ocassionally it can produced an eosinophilic meningoencephalitis in men by larvae accidental ingestion. Methods: A qualitative study was performed from a focal group by a semi-structural survey in a health area from San Miguel del Padrón municipality. Objectives: To describe the actions developed by the local sanitarian authorities for the control of African giant snails between 2016 and 2018 and the appearance of a patient suffering from eosinophilic meningoencephalitis due to Angiostrongylus cantonensis linked to the presence of this snail. Results: It has been established an eradication strategy for the elimination of this invasive species based on a community work. Two years later, it was observed again the giant African snail in the area with a patient suffering from Angiostrongylus cantonensis eosinophilic meningoencephalitis epidemiologically associated. Conclusions: The 2016 actions were not efficient due to the emerging vector and the further finding of a patient linked with the parasite(AU)

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)

Establishment of a recombinase-aided isothermal amplification assay for nucleic acid detection of Angiostrongylus cantonensis / 中国血吸虫病防治杂志

Objective To establish a recombinase-aided isothermal amplification (RAA) assay for the nucleic acid detection of Angiostrongylus cantonensis. Methods The internal transcribed spacer-1 (ITS1) gene sequence of A. cantonensis was used as the detection target sequence, and the specific primers and probes were designed and synthesized, followed by screening of the primers and probes with the highest specificity, to establish the basic and fluorescent RAA assay for nucleic acid detection of A. cantonensis. The sensitivity of the fluorescent RAA assay was evaluated by using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the template DNA samples, and the specificity of the fluorescent RAA assay was evaluated by using the genomic DNA from A. cantonensis, Schistosoma mansoni, Ascaris lumbricoides, Clonorchis sinensis, Echinococcus granulosus and Ancylostoma duodenale, as well as Pomacea canaliculata and Biomphalaria straminea snail tissues as the template DNA samples. Results A fluorescent RAA assay was successfully established for nucleic acid detection of A. cantonensis, which achieved real-time amplification of the specific DNA fragment of A. cantonensis within 20 min at 37 ℃. By using the target gene fragment sequence-contained recombinant plasmids at various copy numbers and the genomic DNA from A. cantonensis as the DNA templates, the lowest detection limits of the fluorescent RAA assay were 10 copies/μL of recombinant plasmids and 100 pg/μL of genomic DNA, respectively. The fluorescent RAA assay was negative for detection of the genomic DNA from A. cantonensis, S. mansoni, A. lumbricoides, C. sinensis, E. granulosus, A. duodenale, and P. canaliculata and B. straminea snail tissues. Conclusions A simple, rapid fluorescent RAA assay has been successfully established, which has a high sensitivity and specificity for the nucleic acid detection of A. cantonensis.

Diagnóstico neuroinmunológico de meningoencefalitis eosinofílica producida por Angiostrongylus cantonensis / Neuroimmunological diagnosis of eosinophilic meningoencephalitis caused by Angiostrongylus cantonensis

El diagnóstico de la meningoencefalitis por Angiostrongylus cantonensis se establece por la presencia de las larvas del helminto en el líquido cefalorraquídeo, pero esta evidencia es muy difícil de encontrar ya que las larvas son lábiles en este medio y no se hallan con frecuencia. Debido a que en Cuba, la presencia del parásito se remonta a 1981 y este parásito es el único que puede provocar esta enfermedad en el país, se realiza una revisión con el objetivo de revisar la literatura publicada sobre el tema para acopiar toda la evidencia que ayude al diagnóstico auxiliar de meningoencefalitis eosinofílica. Se propone que el estudio de la síntesis intratecal de IgE y C3c, unido al patrón de síntesis local de IgA+IgG principalmente y de IgG1+ IgG2 resultan las más indicadas. Existen otras proteínas que pudieran auxiliar como la síntesis intratecal de C4 y en menor proporción MBL(AU)

Diagnosis of meningoencephalitis due to Angiostrongylus cantonensis is based on the presence of helminth larvae in cerebrospinal fluid, but such evidence is very hard to find, since the larvae are labile in this medium and cannot be spotted easily. Based on the fact that presence of the parasite in Cuba dates back to 1981, and this is the only agent of the disease in the country, a review was conducted with the purpose of going over the published literature about the topic and gather evidence leading to the auxiliary diagnosis of eosinophilic meningoencephalitis. The study of the intrathecal synthesis of IgE and C3c, alongside the local synthesis pattern for IgA+IgG mainly and IgG1+IgG2, are proposed as the most appropriate. Other useful proteins are the intrathecal synthesis of C4 and to a lesser extent MBL(AU)

Strongylides in Achatina(Lissachatina)fulica (Mollusca, Achatinidae) in Havana, Cuba / Strongylides in Achatina(Lissachatina)fulica (Mollusca, Achatinidae) in Havana, Cuba

ABSTRACT Achatina (Lissachatina) fulica was introduced in Cuba in 2014 for african religious purposes and nowadays, mainly by human activity, it is widespread all over the country and, where besides a general nuisance for people it is a pest and also a public health concern, since it is one of the natural intermediate host of Angiostrongylus cantonensis, ethiological agent of the meningoencephalitis. As in Havana is experiencing the explosive phase of the invasion, LABCEL has been receiving samples of these molluscs for identification and search for Angiostrongylus cantonensis larvae. While examining samples of A. fulica different larvae were obtained, as strongylides found in the interior of the pallial cavity of A. fulica.This is the first report in San Miguel del Padron and Regla municipalities of the development of larvae in A. Fulica evidencing the health importance of this mollusc in the potential transmission of eosinophilic meningoencephalitis. Since the spread of A. fulica is pointed out in the literature as one of the main causative spread of the meningoencephalitis caused by A. cantonensis the authors emphasize the need of sanitary vigilance of snails and rats from vulnerable areas for A. cantonensis introduction as the port side areas like these municipalities.

RESUMEN Achatina (Lissachatina) fulica se introdujo en Cuba en 2014 con fines religiosos africanos y hoy en día, principalmente por actividad humana, está muy extendida en todo el país y, además de una molestia general para las personas, es una plaga y también un problema de salud pública, ya que es uno de los huéspedes intermedios naturales de Angiostrongylus cantonensis, agente etiológico de la meningoencefalitis. Como en La Habana está experimentando la fase explosiva de la invasión, LABCEL ha estado recibiendo muestras de estos moluscos para su identificación y búsqueda de larvas de Angiostrongylus cantonensis. Mientras se examinaban muestras de A. fulica, se obtuvieron diferentes larvas, como strongylides encontrados en el interior de la cavidad paliar de A. fulica. Este es el primer informe en los municipios de San Miguel del Padrón y Regla sobre el desarrollo de larvas en A. Fulica evidenciando La importancia para la salud de este molusco en la transmisión potencial de la meningoencefalitis eosinofílica. Dado que la propagación de A. fulica se señala en la literatura como una de las principales causas de la meningoencefalitis causada por A. cantonensis, los autores enfatizan la necesidad de vigilancia sanitaria de caracoles y ratas de áreas vulnerables para la introducción de A. cantonensis como zonas de babor como estos municipios.

El caracol gigante africano (Achatinafulica) y sus efectos en la salud humana / The giant African snail (Achatinafulica) and its effects on human health / O caracol gigante africano (Achatinafulica) e seus efeitos na saúde humana

RESUMEN Introducción: el caracol gigante africano (CGA) o Achatinafulica se considera una de las cien especies exóticas invasoras más dañinas del mundo. Su principal riesgo para la salud humana resulta de la posibilidad de actuar como huésped de nematodos. Desarrollo: el CGA es el hospedero intermediario de varios parásitos incluidos Aelurostrongylusabstrusus, Angiostrongyluscantonensis, Angiostrongyluscostaricensis, Schistosomamansoni, Hymenolepisspp. Y Fasciola hepática. El A. cantonesises el principal microorganismo causal de la meningitis eosinofílica (ME) y es agente trasmisor de la bacteria gramnegativa Aeromonashydrophila. Entre las manifestaciones clínicas más comunes de la ME se incluyen cefalea intensa, rigidez nucal, náuseas vómitos y parestesias. La detección de eosinófilos en el líquido cefalorraquídeo (LCR) y la sangre periférica contribuyen a su diagnóstico. El tratamiento en formas graves de la ME se basa en el uso de corticosteroides y punciones lumbares seriadas para extracción del LCR. El empleo de antihelmínticos es controversial. Conclusiones: la presencia del caracol gigante africano en Cuba eleva el riesgo de enfermedades. La aparición de manifestaciones clínicas del sistema nervioso central impone la necesidad de indagar sobre la exposición a este molusco y demanda de la búsqueda de signos y síntomas de meningitis eosinofílica. Se requiere desarrollar en el futuro estudios controlados y aleatorizados sobre la eficacia de los fármacos para el tratamiento de la enfermedad, entre ellos los antihelmínticos.

ABSTRACT Introduction: the giant African snail (CGA) or Achatinafulica is considered one of the one hundred most harmful invasive alien species in the world. Its main risk to human health results from the possibility of acting as a host of nematodes. Development: the CGA is the intermediate host of several parasites including Aelurostrongylusabstrusus, Angiostrongyluscantonensis, Angiostrongyluscostaricensis, Schistosomamansoni, Hymenolepisspp. And Fasciola hepatica. A. cantonesises is the main causative organism of eosinophilic meningitis (ME) and is a transmitting agent of the gram-negative bacterium Aeromonashydrophila. The most common clinical manifestations of ME include intense headache, nuchal rigidity, nausea, vomiting and paresthesias. The detection of eosinophils in the cerebrospinal fluid (CSF) and peripheral blood contribute to its diagnosis. Treatment in severe forms of EM is based on the use of corticosteroids and serial lumbar punctures for CSF removal. The use of anthelmintics is controversial. Conclusions: the presence of the giant African snail in Cuba increases the risk of diseases. The appearance of clinical manifestations of the central nervous system imposes the need to inquire about the exposure to this mollusk and demand the search for signs and symptoms of eosinophilic meningitis. In the future, controlled and randomized studies on the efficacy of drugs for the treatment of the disease, including anthelmintics, need to be developed.

RESUMO Introdução: o caramujo gigante africano (CGA) ou Achatinafulica é considerado uma das cem espécies exóticas invasoras mais nocivas do mundo. Seu principal risco para a saúde humana resulta da possibilidade de atuar como hospedeiro de nematóides. Desenvolvimento: A CGA é o hospedeiro intermediário de vários parasitas incluindo Aelurostrongylusabstrusus, Angiostrongylus cantonensis, Angiostrongyluscostaricensis, Schistosoma mansoni, Hymenolepisspp. E Fasciola hepatica. A. cantonesises o principal organismo causador de meningite eosinofílica (ME) e é agente de bactérias gram-negativas bactérias Aeromonas hydrophila transmissão. As manifestações clínicas mais comuns da EM incluem cefaléia intensa, rigidez de nuca, náusea, vômito e parestesias. A detecção de eosinófilos no líquido cefalorraquidiano (LCR) e no sangue periférico contribui para o seu diagnóstico. O tratamento em formas graves de EM baseia-se no uso de corticosteróides e punções lombares em série para remoção do LCR. O uso de anti-helmínticos é controverso. Conclusões: a presença do gigante caramujo africano em Cuba aumenta o risco de doenças. O aparecimento de manifestações clínicas do sistema nervoso central impõe a necessidade de investigar a exposição a este molusco e procura de sinais e sintomas de meningite eosinofílica. No futuro, estudos controlados e randomizados sobre a eficácia de medicamentos para o tratamento da doença, incluindo anti-helmínticos, precisam ser desenvolvidos.

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.

Infección por Angiostrongylus cantonensis (Nematoda: Metastrongylidae) en Rattus rattus (Rodentia: Muridae) en una localidad de La Habana, Cuba / Infection by Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Rattus rattus (Rodentia: Muridae) in a locality of Havana, Cuba

Introducción: La meningoencefalitis eosinofílica producida por Angiostrongylus cantonensis (Chen, 1935), es una zoonosis emergente presente en Cuba. En el país existen escasos estudios de prevalencia de infección en los hospederos definitivos, que puedan determinar sitios de riesgo para el establecimiento de medidas efectivas en la prevención de la enfermedad. Objetivo: Determinar la prevalencia de infección por A. cantonensis en una población natural de R. rattus, su relación con la estructura poblacional y la época del año en una finca que pertenece al Programa de la Agricultura Urbana y Suburbana de Cuba. Material y Métodos: Se realizó un estudio descriptivo en el municipio La Lisa, La Habana. Se hicieron capturas de roedores mensuales durante los períodos lluvioso y poco lluvioso. Se examinaron las arterias pulmonares de los roedores capturados en búsqueda de parásitos adultos. El índice parasitológico de prevalencia fue calculado y comparadas las frecuencias entre los períodos del año y la edad ecológica. Resultados: Se capturaron 63 roedores identificados como Rattus rattus, de ellos 46,03 por ciento estuvo infectado con A. cantonensis, con un incremento de la infección en los individuos adultos (59,46 por ciento) y en el período lluvioso (55,88 por ciento). Conclusiones: Se demuestra por primera vez en Cuba la infección de A. cantonensis en R. rattus. La presencia de individuos adultos, la alta abundancia de roedores y la temporada lluviosa son los factores que incidieron en una mayor infección de A. cantonensis, y que aumentan la probabilidad de transmisión a los hospederos intermediarios y, por ende, el riesgo de transmisión al humano(AU)

Introduction: Eosinophilic meningitis caused by Angiostrongylus cantonensis (Chen, 1935) is an emergent zoonosis present in Cuba. In the country, few studies about the prevalence of infection in definitive hosts, which can determine risk sites for the establishment of effective measures to prevent the disease, have not been carried out so far. Objective: To determine the prevalence of infection with Angiostrongylus cantonensis in a natural population of Rattus rattus, its relationship with the population structure, and the season of the year in an urban farm field belonging to the Programme of Urban and Suburban Agriculture of Cuba. Material and Methods: A descriptive study was conducted in La Lisa Municipality, Havana, Cuba. The rats were collected monthly during the rainy and dry seasons. The pulmonary arteries of the captured rodents were examined for adult worms. The prevalence of parasitological indices was calculated. The frequencies of infection were compared between the seasons of the year and ecological ages. Results: A total of 63 rodents identified as Rattus rattus were captured. Of the total of individuals captured, 46.03 percent were infected with A. cantonensis, with an increase of infection in adult individuals (59.46 percent) and during the rainy season (55.88 percent). Conclusions: The infection of A. cantonensis in its definitive host R. rattus, and its circulation in the study area in the analyzed period was demonstrated for the first time in Cuba. The presence of adult rats, the high quantity of rodents and the rainy season were the factors that contributed to a greater infection of A. cantonensis, which increase the probability of transmission to intermediate hosts, and consequently, the risk of transmission to humans(AU)

Human neuroimmune response against angiostrongylus cantonensis

Introduction: Angiostrongylus cantonensis is a zoonotic pathogen that causes human angiostrongyliasis; its main clinical manifestation is eosinophilic meningitis. It was reported in Cuba for the first time in America. Objective: To review the main immunological findings about the human neuroimmune response against this parasite. Methods: This paper is based on a review of the papers mainly from Cuban authors published in the last 10 years about the human neuroimmune response against this helmint. This information becomes more relevant after the introduction of the African giant snail Lissachatina fulica in Cuba in 2014. Results: The humoral immune response is based on the immunoglobulin intrathecal synthesis. When the third-stage larvae go to the central nervous system at the first lumbar puncture there are no major immunoglobulin synthesis. One week later an immune intrathecal response is done by a two-class major immunoglobulin class mainly IgG+ IgA Intrathecal activation of complement is evident of intrathecal synthesis of major immunoglobulins during this disease. The activation of complement system components in cerebrospinal fluid is relevant to the understanding of this tropical disease, which is emerging in the Western hemisphere. Intrathecal synthesis of at least one of the major immunoglobulins and a wide spectrum of patterns may be observed. Although intrathecal synthesis of C3c and IgE is always present, C4 intrathecal synthesis does not occur in every patient. The diversity of intrathecal synthesis and activation of the different complement pathways enables their division into three variant groups. In each one could be finding the activation of one or several complement pathways including the participation of MBL, MASP-2 and ficolins as part of the lectin pathway complement activation. Conclusion: The neuroimmune response against Angiostrongylus cantonensis eosinophilic meningoencephalitis is an example of the host-parasite interaction(AU)