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.

Variation in fecal egg counts in horses managed for conservation purposes: individual egg shedding consistency, age effects and seasonal variation.

Cyathostomins are the most prevalent equine intestinal parasites and resistance has been reported in these nematodes against all 3 licensed anthelmintic classes. Strategies need to be developed that are less dependent upon drugs and more reliant on management-based control. To develop these we need to understand natural transmission patterns better. Here, we analysed longitudinal fecal egg count (FEC) data from 5 pony populations used for conservation purposes. We tested how egg excretion varied amongst populations and individuals, and how this was affected by age and climate. There was evidence for consistency in FECs over time at the individual level; this was generally weak and accounted for <10% of the total variance. Animals <5 years old had higher FECs and there was profound seasonal variation in FECs, with highest levels recorded in spring/summer. Effects of monthly temperature and rainfall explained most, but not all, of the observed seasonal variation and associations between climate measures and FECs were stronger in younger versus adult animals. One population was occasionally treated with anthelmintics and analysis of this population suggested that treatment substantially altered the seasonal dynamics. This paper highlights the variability in strongyle egg excretion amongst individuals and the factors involved in this variation.

Seasonal transmission of gastrointestinal parasites of equids in southern Louisiana.

Parasite-naive pony foals were used as sentinels to monitor transmission of gastrointestinal parasites of equids in Louisiana during 4 seasons of the year. Two annual periods were studied, 1988-1989 and 1992-1993. Two or 3 foals each season were turned out to graze a contaminated pasture along with resident parasitized mares and their foals. After a grazing period of 8 wk, sentinel ponies were held in a parasite-free box stall for a period of 6 wk to allow parasites to develop, thus enhancing the evaluation of hypobiotic stages. Following this holding period, necropsies were performed for complete parasite recoveries. Data show that transmission of large and small strongyles occurs during all seasons in southern Louisiana, with highest levels of transmission occurring in the winter and only minimal transmission taking place in the summer. Numbers of mucosal cyathostomes, as well as total cyathostome numbers, were highest in the winter, and luminal cyathostome numbers were highest in the spring. Transmission of Anoplocephala perfoliata and Parascaris equorum occurred during all seasons of the year, although numbers of P. equorum were reduced in spring 1989 and 1993. Gasterophilus intestinalis instars were recovered from fall and winter sentinels only. Oxyuris equi L4 were found all seasons 1 yr, but only during the fall and winter of the final year.

Epidemiology of strongyles in ponies in Ontario.

The transmission of strongyles among 54 Shetland-cross mature ponies was examined from May 30 to November 22, 1983 when the ponies were on pasture and over the ensuing winter when they were in loose housing. Fecal and pasture herbage samples were taken fortnightly through the pasture season and periodically thereafter. Three foals born and reared on pasture were weaned and removed from pasture, two in early August and one in mid-September, and housed for a period before necropsy. Daily maximum and minimum air temperature and total precipitation were recorded. The mean fecal strongyle egg count was highest in the spring and early summer and lowest over the winter. Few larvae were found on the herbage in late May and their numbers were near zero by the third week in June. Subsequently, the numbers increased, were highest from late August through to mid-October and then declined and were low over the winter. Few strongyles were found in two foals removed earlier in the season, and many in the one later. The transmission of strongyles appeared to occur, therefore, principally from mid-summer to mid-fall.

Control of strongylosis in horses by alternate grazing of horses and sheep and some other aspects of the epidemiology of Strongylidae infections.

Alternate grazing of horses and sheep as a control measure for gastrointestinal helminthiasis was studied in three grazing experiments in 1981, 1982 and 1983. Each year a group of three mare yearling Shetland ponies, which were kept on a small pasture from spring to autumn, were compared with a similar group which grazed a similar or the same pasture until July and were subsequently removed to a similar pasture which had been grazed by sheep from April to July. In addition both groups were treated with an anthelmintic when the latter group was removed to the sheep pasture. Pasture larval counts and worm counts and, in 1982 and 1983, faecal egg counts, clinical condition, total protein, albumin and beta-globulin levels demonstrated that the groups removed to sheep pasture acquired considerably lower burdens of nematodes of the subfamilies Cyathostominae and Strongylinae, but considerably higher burdens of Trichostrongylus axei than the groups which were not moved. These T. axei infections resulted in higher serum pepsinogen levels in the former groups compared to the latter in 1981 and 1982. At necropsy an important part of the T. axei burdens and, in 1982 and 1983, the Cyathostominae burdens consisted of inhibited early third stage larvae. A total of 20 species of the subfamily Cyathostominae and 7 species of the Strongylinae were found. Generally the composition of species was in agreement with other observations in western Europe, the most common species being: Cylicostephanus longibursatus, Cylicostephanus minutus, Cylicostephanus calicatus, Cylicostephanus goldi, Cylicostephanus poculatus, Cyathostomum labratum, Cyathostomum coronatum, Cyathostomum catinatum, Cylicocyclus leptostomus, Cylicocyclus nassatus, Cylicocyclus insigne, Strongylus edentatus and Strongylus vulgaris.

[Strongyloides westeri Ihle, 1917 (Nematoda: Strongyloididae). I. Parasitological features of natural infection (author's transl)]. / Strongyloides westeri Ihle. 1917 (Nematoda: Strongyloididae). I. Parasitologische aspecten van de natuurlijke infectie.

Patent S. westeri infection is particularly common in unweaned foals (61.2 per cent). It is much less common in foals which have been weaned (15.4 per cent). Examination of the faeces of ten artificially reared foals (free from worms) did not supply any evidence of possible prenatal (intra-uterine) helminth infection. In one Shetland pony mare, larvae of S. westeri were found to be present in the milk on the tenth, twenty-fourth and thirty-second day after parturition. Larvae were not detected in the milk of the other mares but all foals showed patent S. westeri infection within from thirteen to sixteen days after parturition. In view of the conditions in which the animals were kept, this can only have been due to galactogenous (trans-mammary) infection.