Morphological and molecular identification of trematode isloates from laying ducks in Nanchang City / 中国血吸虫病防治杂志

Objective To identify the species of trematodes isolated from laying ducks in Nanchang City using morphological and molecular approaches. Methods Trematodes were isolated from the hepatobiliary duct, gallbladder and large intestine of market-sold laying ducks in Nanchang City. Following morphological characterization, total DNA was extracted from all trematode specimens, and internal transcribed spacer region (ITS) and cytochrome C oxidase subunit 1 (Cox1) genes were amplified using PCR assay and sequenced. Sequence alignment was performed using the Blast software, and homology and phylogenetic analyses were done in the trematode isolates based on ITS and Cox1 gene sequences. Results The morphological characteristics of two trematode isolates from the large intestine of laying ducks were similar to those of Echinostoma revolutum and E. miyagawai, and the morphological characteristics of eight trematode samples isolated from the hepatobiliary duct and gallbladder of laying ducks were similar to those of Amphimerus anatis. The ITS and Cox1 gene sequences of the two trematode isolates from the large intestine of laying ducks had 99.3% and 98.9%-99.4% homology with E. miyagawai, and the phylogenetic analysis showed that two trematode isolates had the closest genetic relationship with E. miyagawai based on ITS and Cox1 gene sequences. The ITS gene sequences of eight trematode isolates from the hepatobiliary duct and gallbladder of laying ducks shared 95.1%-95.5% with Opisthorchis sudarikovi and Clonorchis sinensis, while the Cox1 gene sequences of eight trematode isolates from the hepatobiliary duct and gallbladder of laying ducks shared 86.3%-86.4% and 85.5%-85.7% with O. viverrini and O. sudarikovi. ITS gene sequence-based phylogenetic analysis showed that the duck-derived trematode isolates had the closest genetic relationship with C. sinensis, and Cox1 gene sequence-based phylogenetic analysis showed that the duck-derived trematode isolates had the closest genetic relationship with Metorchis orientalis and O. viverrini. Conclusions The trematode isolates from the large intestine of laying ducts in Nanchang City may be E. miyagawai, and the trematode isolates from the hepatobiliary duct and gallbladder may be an unidentified trematode species of the family Opisthorchiidae.

Evaluation of the reproductive profile of Subulina octona (Gastropoda, Subulinidae) experimentally infected by Paratanaisia bragai (Digenea, Eucotylidae) / Avaliação do perfil reprodutivo de Subulina octona (Gastropoda, Subulinidae) infectada experimentalmente por Paratanaisia bragai (Digenea, Eucotylidae)

Abstract Snails infected by trematodes may increase or decrease their reproductive activity in response to the presence of infection. Our aim was to verify the reproductive alterations in Subulina octona after infection by Paratanaisia bragai. The infected snails were individually exposed for 24 hours to 20 parasite eggs and four groups were formed (10, 20, 30 and 40 d.p.i.- days after infection), along with control groups. Every 10 days, the number of eggs in the reproductive tract, number of eggs hatched, galactogen content and histopathological changes were evaluated. The reproductive in the control and infected snails presented an alternating pattern, where periods of high production of eggs and newly hatched were followed by periods of low production. However, in relation to the amount of galactogen, both control and infected groups followed the same pattern of variation. In the histology, we observed the presence of male and female gametes with marked reduction in the number of oocytes. The results indicate that the intra-snail development of the parasite affects the reproductive biology of the host.

Resumo Moluscos infectados por trematódeos podem aumentar ou diminuir sua atividade reprodutiva em resposta à presença da infecção. Nosso objetivo foi verificar as alterações reprodutivas de Subulina octona após a infecção por Paratanaisia bragai. Os moluscos infectados foram individualmente expostos durante 24 horas a 20 ovos do parasito e quatro grupos foram formados (10, 20, 30 e 40 d.p.i. - dias pós infecção), com respectivos grupos controle. A cada 10 dias, o número de ovos no trato reprodutivo, o número de ovos eclodidos, o conteúdo de galactogênio e alterações histopatológicas eram avaliadas. O padrão reprodutivo nos moluscos controle e infectados evidenciou um comportamento alternante, nos quais períodos de alta produção de ovos e filhotes foram seguidos por períodos de baixa produção. No entanto, em relação ao conteúdo de galactogênio, moluscos controle e infectados seguiram o mesmo padrão de variação. Na histologia, observamos a presença de gametas masculinos e femininos com acentuada redução no número de óocitos. Os resultados indicam que o desenvolvimento intramolusco do parasito afeta a biologia reprodutiva do hospedeiro.

Parásitos gastrointestinales en mamíferos silvestres cautivos en el Centro de Fauna de San Emigdio, Palmira (Colombia) / Gastrointestinal parasites in captive wild mammals at the fauna center from San Emigdio, Palmira (Colombia)

RESUMEN La parasitosis intestinal en mamíferos silvestres es una de las principales complicaciones debido a las condiciones exógenas del cautiverio; predisponen al animal a complicaciones fisiológicas o infecciones secundarias que impiden su rehabilitación y reintroducción. El objetivo de esta investigación fue determinar la presencia de parásitos gastrointestinales en mamíferos silvestres del Centro de Atención y Valoración de Fauna silvestre del Centro de Educación Ambiental San Emigdio, San Emigdio, Palmira (Colombia). Se tomaron muestras fecales de 25 animales cautivos en el Centro de Atención y Valoración y fueron analizadas mediante dos técnicas: a) montaje con solución salina al 0,85 % y solución de lugol al 1% y b) técnica de flotación por solución saturada (Sheather) con densidad de 1.28g/ml, encontrando un 36% de positividad. Se encontró Enterobius vermicularis, Fasciola sp., Entamoeba sp. y Ancylostoma sp. El grupo de primates no humanos presentó cargas parasitarias más altas con respecto a felinos, caninos y demás mamíferos del estudio. Los microorganismos identificados son reconocidos como parásitos causantes de complicaciones en animales cautivos y en libertad; al igual, son catalogados como posibles riesgos zoonóticos.

ABSTRACT Intestinal parasitosis in wild mammals is one of the main complications due to the exogenous conditions of captivity. They predispose the animal to physiological complications or secondary infections that prevent its rehabilitation and reintroduction. The objective is to determine the presence of gastrointestinal parasites in wild mammals from the Wildlife Care and Valuation Center of the San Emigdio Environmental Education Center, San Emigdio, Palmira (Colombia). Fecal samples were taken from 25 captive animals in Care and Valuation Center being analyzed using two techniques: a) assembly with 0.85% saline solution and 1% lugol solution and b) saturated solution flotation technique (Sheather) with a density of 1.28g/ml, with a 36% of positivity. Enterobius vermicularis, Fasciola sp., Entamoeba sp. and Ancylostoma sp. were found. The group of non-human primates had higher parasitic intensity compared to felines, canines and other mammals in the study. The identified microorganisms are recognized as parasites causing complications in captive animals and in free life; likewise, they are classified as possible zoonotic risks.

Reporte de Pseudosuccinea columella infectados con Fasciola hepática en Sierra de los Cuchumatanes, Guatemala / Report ofPseudosuccinea columella,infected withFasciola hepaticaat Sierra de los Cuchumatanes, Guatemala

RESUMEN Objetivo. Identificar la infección natural de caracoles de agua dulce con Fasciola hepatica en una localidad del altiplano de Guatemala. Materiales y métodos. Se colectaron caracoles de agua dulce en una aldea endémica de fascioliasis, en la localidad de Paquix, en el departamento de Huehuetenango, ubicado a ~3.300 msnm. La identificación de la especie de caracol se basó en las características morfológicas observadas por estereoscopio usando una clave de identificación. La búsqueda de fases del trematodo se realizó mediante la inspección visual externa con fuente de luz y la disección e inspección visual dentro del molusco bajo estereoscopio y microscopio. Resultados. 260 caracoles fueron encontrados e identificados como Pseudosuccinea columella. Se examinaron los especímenes colectados y se encontraron dos caracoles infectados de forma natural con fases larvarias de F. hepatica. Conclusiones . Este es el primer reporte de este hospedero intermediario portando formas de F. hepatica en Guatemala. Es necesario aumentar los reportes de este parásito y de sus interacciones ecológicas en otras áreas no estudiadas de Guatemala y Centro América, debido al riesgo latente de infección para poblaciones de animales herbívoros y humanos.

ABSTRACT Objective. Identify the natural infection of freshwater snails as an intermediate host of Fasciola hepatica in Guatemala. Materials and methods. Freshwater snails were collected in a high-altitude village (3.000 mamsl) from Huehuetenango department, where fasciolasis is endemic. The identification of the snail species was based on the morphological characteristics observed under the stereoscope using an identification key. The trematode phases were searched externally by visual inspection using a light source, and internally by dissection and visual inspection of the tissues under a stereoscope and microscope. Results. 260 snails were found and identified as Pseudosuccinea columella. Two were found naturally infected with larval phases of F. hepatica. Conclusions. This is the first report of P. columella carrying phases of F. hepatica in the highlands of Guatemala. It is necessary to increase the research of the ecology of this parasite in other understudied areas in Guatemala and Central America, due to the latent risk of infection for populations of herbivorous animals and humans.

Pérdidas económicas y prevalencia de Fasciola hepática en bovinos sacrificados en dos provincias cubanas / Economic losses and prevalence of Fasciola hepatica in cattle slaughtered in two cuban provinces

RESUMEN Objetivo. Determinar las pérdidas económicas producidas por el decomiso de hígados afectados y la prevalencia de Fasciola hepatica en bovinos sacrificados en las provincias de Holguín y Camagüey, Cuba. Materiales y m étodos. Fueron utilizados los resultados del diagnóstico anatomopatológico realizado en los mataderos Felipe Fuentes y César Escalante durante el periodo comprendido entre enero de 2012 y diciembre de 2018. A partir de la cantidad de animales sacrificados y los afectados se calcularon las pérdidas que alcanzaron un valor de $80.312 USD (Holguín) y $32.7152 USD (Camagüey) para todo el período. Se realizaron análisis de comparación de proporciones para los animales afectados por F. hepatica y las pérdidas económicas por decomiso de hígados, mediante una prueba Chi-cuadrado para determinar la existencia o no de diferencias significativas entre las proporciones y un análisis de medias (ANOM) para determinar cuáles proporciones son significativamente distintas del promedio general. Resultados. Se observó que en 11 meses los animales afectados difirieron significativamente (p<0.001) entre los mataderos excepto en el mes de julio, mientras que las pérdidas totales por decomisos de hígados afectados mostraron diferencias significativas (p<0.001) en todos los meses para el periodo evaluado. Conclusiones. Los mayores valores para las pérdidas económicas y prevalencia por el decomiso de hígados afectados por F. hepatica se presentaron en la provincia de Camagüey lo que pudiera estar relacionado con las condiciones climáticas diferentes, por lo que se recomienda evaluar la dinámica de los hospederos intermedios y las etapas larvarias de este trematodo en las dos provincias estudiadas.

ABSTRACT Objective. To determine the economic losses resulting from condemnation of affected livers and the presence of Fasciola hepatica in slaughtered cattle in the provinces of Camagüey and Holguín, Cuba. Materials and Methods. This study was based on the results from an anatomo-pathological examination performed at Felipe Fuentes and César Escalante slaughterhouses between January 2012 and December 2018. The losses, which totaled $ 80 312 USD (Holguín) and $ 327 152 USD (Camagüey), were estimated from the number of slaughtered and affected animals throughout the period. Analyses for the comparisons of proportions were made to animals affected by F.hepatica, whereas the economic losses due to liver condemnation were analyzed by Chi-square to determine the existence of significant differences among the proportions. Analysis of means (ANOM) was made to determine the significantly different proportions within the general average. Results. Significant differences (p<0.001) were observed in animals from different slaughterhouses in 11 months, excluding July. Meanwhile, the total losses due to condemnation of affected livers underwent significant differences (p<0.001) in all the months of the evaluation period. Conclusions. The highest values of economic losses and prevalence due to condemnation of livers affected by F.hepatica were observed in the province of Camagüey, which may have been linked to varying climatic conditions. Hence, evaluation of intermediary host dynamics and the larval stages of the trematode in the two provinces studied were recommended.

Molecular identification of Tricula spp. and the parasitized trematode cercariae in schistosomiasis-endemic areas of Yunnan Province / 中国血吸虫病防治杂志

Objective To characterize a species of the genus Tricula and parasitized trematodes in schistosomiasis-endemic areas of Yunnan Province using a molecular analysis, so as to understand their taxonomic positions. Methods Tricula spp. and Oncomelania snails were collected from Xiangyun County, Yunnan Province, and cercaria parasitizing snails were observed using crushing followed by microscopy. Cercaria parasitizing Tricula snails at various morphologies were sampled using a shedding method. Genomic DNA was extracted from snail soft tissues and cercariae, and the 16S rRNA, COI, 28S rDNA genes in snails and the ND1 and 28S rDNA genes in cercariae were amplified using a PCR assay and sequenced. The species of Tricula snails and their parasitized trematodes was characterized using sequence alignment and phylogenetic analysis. Results Among 382 Tricula snails detected, there were three types of trematode cercariae found, including the non-forked (20.94%, 80/382), double-forked (3.40%, 13/382) and swallow shapes (7.07%, 27/382). Sequence and phylogenetic analyses showed that the 16S rRNA, COI and 28S rDNA gene sequences of this species of Tricula had high homology to those in Delavaya dianchiensis, and were clustered in a branch. Sequencing analysis of the ND1 and 28S rDNA genes revealed that the non-forked cercariae belonged to the family Pleu- rogenidae, the swallow-shaped cercariae belonged to the family Opecoelidae, and the double-forked cercariae belonged to another species of the genus Schistosoma that was different from S. sinensium and S. ovuncatum. Conclusion The species and taxonomy of Triculla spp. and their parasitized trematodes are preliminarily determined in schistosomiasis-endemic areas of Yunnan Province; however, further studies are required to investigate the more definite taxonomy and pathogenicity.

First report of Diplostomidae metacercariae (Trematoda: Digenea) in African catfish Clarias gariepinus (Siluriformes: Clariidae) in Brazil / Primeiro relato de metacercárias de Diplostomidae (Trematoda: Digenea) em bagre africano Clarias gariepinus (Siluriformes, Clariidae) no Brasil

Abstract Clarias gariepinus is a fish from North of South Africa and was later introduced in several countries, including Brazil. The present study aimed to describe the first report of Diplostomidae metacercariae in C. gariepinus in Brazil. For this, 30 C. gariepinus were captured in a lake in the city of Campos dos Goytacazes, RJ, Brazil. Fishes were euthanized using freezing and necropsied for collection of parasites. The organs were dissected and analyzed for the presence of parasites that were processed for light and scanning electron microscopy. Trematodes were stained with Semichon's Carmine and Gomori's Trichrome, observed and schematized under a light microscope with image analysis software. A total of 190 trematodes were collected from the gills, suprabranchial organs, heart, stomach, intestinal mesentery, liver and body cavity of the fish. The parasites had a foliaceous body divided by a discrete constriction, without genital primordia, and a holdfast organ present at the posterior region, typical of metacercariae of the family Diplostomidae. It was classified as the 'Diplostomulum' morphotype, based on the morphology of the reserve bladder structure. This is the first report of the metacercariae of Diplostomidae parasitizing C. gariepinus in the Americas. This fish acts as an intermediate or paratenic host of this digenean in Brazil.

Resumo Clarias gariepinus é um peixe do Norte da África do Sul e posteriormente introduzido em diversos países, incluindo o Brasil. O presente estudo teve como objetivo descrever o primeiro relato de metacercárias em C. gariepinus no Brasil. Para tanto, 30 C. gariepinus foram capturados em um lago na cidade de Campos dos Goytacazes, RJ, Brasil. Os peixes foram eutanasiados por congelamento e necropsiados para a coleta de parasitos. Os órgãos foram dissecados e analisados para a presença de parasitos que foram processados para microscopia ótica e electronica de varredura. Os Trematodeos foram corados com carmim de Semichon e tricrômico de Gomori, observados e esquematizados sob microscópio ótico equipado com software de análise de imagens. Um total de 190 trematodeos foram coletados das brânquias, órgãos suprabrânquiais, coração, estômago, mesentério intestinal, fígado e cavidade corporal dos peixes. Os parasitos tinham corpo foliáceo, dividido por uma discrete contrição, sem primórdio genital, e órgão tribocítico presente na região posterior, típico das metacercárias da fámilia Diplostomidae. Foram classificados como do morfotipo 'Diplostomulum', baseado na morfologia da estrutura da bexiga de reserva. Este é o primeiro relato de metacercárias de Diplostomidae parasitando C. gariepinus nas Américas. Este peixe atua como hospedeiro intermediário ou paratênico deste Digenea no Brasil.

Presence of Paragonimus species within secondary crustacean hosts in Bogotá, Colombia / Presencia de especies de Paragonimus en huéspedes crustaceos secundarios en Bogotá, Colombia

Abstract Background: Paragonimus spp. are trematode parasites that infect human populations worldwide. It is believed that infection rates within Asia reach five to ten percent of the total population. Three of the largest areas of possible infection are Asia, Central and South America as well as Africa, where the total population at risk is estimated to be 293 million people. Humans are infected via ingestion of raw or undercooked decapod crustaceans. Objective: To identify the presence of Paragonimus spp. in crabs from Bogotá, Colombia. Methods: The native crab Neostrengeria macropa and the aquatic invasive crayfish Procambarus clarkii in Bogotá, Colombia, were collected from local markets, pet stores and waterways and dissected to assess the presence of Paragonimus spp. Results: The native crab species, N. macropa (n=29) had an infection prevalence of 17.2%, while the invasive crayfish species, P. clarkii (n=22), had a prevalence of 36.4% combined from both field captured animals and purchased samples. Conclusion: Although the estimated prevalence is lower compared to previous studies in other cities of Colombia, Paragonimus represent a risk to human health. Several environmental factors may contribute to the difference in prevalence including collecting season, rainfall, temperature, altitude and the El Niño Southern Oscillation.

Resumen Antecedentes: Los Paragonimus spp. constituyen un grupo de parásitos tremátodos que infectan a humanos en todo el mundo. Se considera que entre 5 y 10% de la población humana de Asia está infectada. Las áreas con mayor posibilidad de infección son Asia, Centro y Sur América, así como África. Se estima que 293 millones de personas están en riesgo de infección. Los humanos se pueden infectar al consumir crustáceos decápodos crudos. Objetivo: Identificar la presencia de Paragonimus spp. en crustáceos en Bogotá, Colombia. Métodos: Una muestra de cangrejos nativos Neostrengeria macropa y de decápodos invasores Procambarus clarkii fue colectada tanto en mercados locales de Bogotá, como en tiendas de mascotas, ríos, y quebradas. Posteriromente fueron diseccionados para detectar la presencia de Paragonimus spp. Resultados: La prevalencia de la infección en N. macropa (n=29) fue de 17,2%, y en la especie invasora, P. clarkii (n=22), fue de 36,4% (porcentaje combinado de los animales colectados en el campo y los comprados en tiendas). Conclusión: Aunque la prevalencia en este estudio fue más baja que la de otras investigaciones relacionadas, se considera que existe riesgo para la salud humana. Es probable que algunos factores medio ambientales hayan contribuido a la diferencia, incluyendo: temporada de colecta, nivel de lluvias, temperatura, altura, y el fenómeno El Niño.

Molecular Method vs. Traditional Methods for Estimating the Prevalence of Larval Trematode Infections in Some Red Sea Snails

Peat reserves of the Russian Federation are estimated at more than 170.0 billion tons, it makes more than one-third of theworld resources. The use of peat as a component for the preparation of composts is an important factor in increasing theproductivity of agricultural ecosystems. During two cycles of four-course crop rotation ‘potatoes – barley – annual grasses– winter wheat’, we studied the influence of lowland peat, composted peat-poultry manure, cattle manure, their combinedapplication with mineral fertilizers on soil physicochemical properties, nitrifying and cellulosolytic activity of soil andproductivity of crop rotation. Application of cattle manure and composted peat-poultry manure contributes to the increase inthe content of humus in soil by 0.07-0.16%, when combined with mineral fertilizers – by 0.14-0.22%, respectively. Onaverage, the highest yield was noted in the variants with cattle manure and composted peat-poultry manure – 10.75-12.13 tha -1 of grain units (g.u.), while in the check (without fertilizers) it was 8.03 g.u. (t ha -1). That is why peat is more profitableto use in the form of composts, especially as a component of composted peat-poultry manure

Infection Status with Digenetic Trematode Metacercariae in Fishes from Coastal Lakes in Gangwon-do, Republic of Korea

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., Metagonimus spp., Pygidiopsis summa, Centrocestus armatus, Metorchis orientalis, M. taiwanensis, Clinostomum complanatum, Echinostoma spp., Stictodora spp., Diplostomum sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. Metagonimus spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, Tribolodon hakonensis, from 5 lakes, and their density was 14.6 per fish infected. P. summa metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. C. armatus metacercariae were detected in 7 (14.6%) T. hakonensis and 3 (15.0%) Tridentiger brevispinis from Hyang-ho, and 5 (19.2%) Acanthogobius flavimanus from Gyeongpo-ho. Stictodora spp. metacercariae were found in 4 fish species, i.e., Tridentiger obscurus, Tridentiger trigonocephalus, Chelon haematocheilus, and Acanthogobius lactipes, from Gyeongpo-ho. Total 15 C. complanatum metacercariae were detected in 2 (9.1%) crucian carp, Carassius auratus, from Songji-ho. M. taiwanensis metacercariae were found in T. hakonensis from Hyang-ho and Gyeongpo-ho and in Pseudorasbora parva from Gyeongpo-ho. Total 11 M. orientalis metacercariae were detected in 3 (6.3%) T. hakonensis from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.

Necrotizing Enteritis Caused by Pharyngostomum cordatum Infection in a Stray Cat

A stray female cat of unknown age, presenting bright red watery diarrhea, was submitted to the Animal and Plant Quarantine Agency for diagnosis. In the small intestines extracted from the necropsied cat, numerous white oval-shaped organisms were firmly embedded in the mucosa and there was thickening of intestinal wall. Histopathological analysis revealed severe necrotizing enteritis, together with atrophied intestinal villi, exfoliated enterocytes, and parasitic worms. Recovered worms were identified as Pharyngostomum cordatum by morphological observation and genetic analysis. Although P. cordatum is known to occur widely in Korea, this is the first clinical description of an infection by P. cordatum causing severe feline enteritis.

Infections with Digenetic Trematode Metacercariae in Freshwater Fishes from Two Visiting Sites of Migratory Birds in Gyeongsangnam-do, Republic of Korea

The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from 2 representative visiting sites of migratory birds in Gyeongsangnam-do, the Republic of Korea (Korea). A totaly 220 freshwater fishes (7 species) were collected from Junam-jeosuji (reservoir), and 127 fishes (7 species) were also collected from Woopo-neup (swamp) in June and October 2017. As the control group, total 312 fish (22 spp.) from Yangcheon in Sancheong-gun, Gyeongsangnam-do were also collected in June and October 2017. All fishes collected in 3 sites were examined with the artificial digestion method. In the fishes from Junam-jeosuji, more than 4 species, i.e., Clonorchis sinensis, Echinostoma spp., Diplostomum spp. and Cyathocotyle orientalis, of DTM were detected and their endemicy was very low, 0.70. More than 6 species, i.e., C. sinensis, Echinostoma spp., Metorchis orientalis, Clinostomum complanatum, Diplostomum spp. and C. orientalis, of DTM were found in the fishes from Woopo-neup, and their endemicy was low, 5.16. In the fishes from Yangcheon, more than 8 species, i.e., C. sinensis, Metagonimus spp., Centrocestus armatus, C. complanatum, C. orientalis, M. orientalis, Echinostoma spp., and Diplostomum spp., of DTM were detected, and their endemicity was relatively high, 95.48. The percentages of avian trematode metacercariae (ATM) were 99.6% and 94.7% in fishes from Junam-jeosuji and Woopo-neup whereas it was 74.1% in the control site, Yangcheon. The above findings suggested that migratory birds partly affect in endemicity of DTM in the fish in the 2 visiting sites in Gyeongsangnam-do, Korea.

Snail transmitters of schistosomiasis and other mollusks of medical and economic importance at the simplício queda única hydroelectric plant, southeast Brazil

Abstract INTRODUCTION This paper presents the results of an extensive survey of freshwater mollusks in the Simplício Queda Única Hydroelectric Development area, Southeast Brazil. METHODS Mollusks were collected between 2008 and 2013. All specimens were examined for the presence of larval trematodes. RESULTS In total, 12,507 specimens classified into 16 genera were obtained. Known snail vectors of schistosomiasis and fascioliasis and exotic species were identified, and new records are reported. CONCLUSIONS No specimens parasitized by larval trematodes of medical interest were detected. However, the results reinforce the importance of surveillance in study areas vulnerable to the occurrence of schistosomiasis transmission.

Recount of reported cases of human fascioliasis in Brazil over the last 60 years

Fascioliasis is an important anthropozoonotic disease caused by the ubiquitous trematode helminth, Fasciola spp. Here, as elsewhere, it is thought that the disease lacks proper reporting, and the available literature does not reflect unreported cases found in the Brazilian population, or new recently reported cases. The purpose of this work was to perform a recount of human fascioliasis (HF) cases in Brazil. For this, we considered all positive cases published in local and international official Journals, from 1950 to 2016. A theoretical-conceptual research method based on a systematic bibliographic review was applied to identify, select and index articles using the Endnote Basic Software. Here, only 48 cases of HF were found, of which 21 (43.7%) occurred in the South of the country. The small number of reported cases reflects the difficulty in diagnosing HF correctly (clinical and fecal tests). This work provides a real figure of HF reported cases in Brazil and has also corrected inaccurate information found in the literature by conducting a historical survey of the disease. Fasciola hepatica is highly endemic in ruminants and, hypothetically, the number of human cases should also be considerably higher than that reported in the literature. These findings call for more attention in regard to this neglected disease in Brazil.

Morphological effects on helminth parasites caused by herbicide under experimental conditions / Efeitos morfológicos em helminto parasito causado por herbicida em condições experimentais

Abstract Helminth parasites have been studied as potential accumulators for different pollutants. Echinostoma paraensei is a foodborne trematode whose vertebrate host, the rodent Nectomys squamipes, is naturally exposed to environmental pesticides. However, little information exists regarding the pesticide's effects on helminths. This study investigated the morphological effects on the trematode, E. paraensei, after experimental Roundup® herbicide exposure, in concentrations below those recommended for agricultural use. After two hours of exposure, scanning electron microscopy (SEM) showed changes to the tegument, such as furrowing, shrinkage, peeling, spines loss on the peristomic collar, and histopathological evidence of altered cells in the cecum and acinus vitelline glands with vacuoles and structural changes to the muscular layers. Glycidic content was decreased, primarily in the connective tissue. As E. paraensei is an intestinal parasite of the semi-aquatic wild rodent, N. squamipes, it is predisposed to pesticide exposure resulting from agricultural practices. Therefore, we emphasize the need to evaluate its impact on helminth parasites, due to their pivotal role in regulating host populations.

Resumo Helmintos parasitos tem sido estudados como acumuladores potenciais para diferentes poluentes. O trematódeo E. paraensei tem como hospedeiro vertebrado o roedor Nectomys squamipes naturalmente exposto a pesticidas no meio ambiente. No entanto, pouca informação está disponível sobre os efeitos dos pesticidas em helmintos parasitos. O presente estudo investigou, em condições experimentais, os efeitos morfológicos no trematódeo E. paraensei após a exposição ao herbicida Roundup®, em concentrações abaixo das recomendadas para a utilização agrícola. A microscopia eletrônica de varredura (MEV) mostrou após duas horas de exposição, alterações no tegumento, como enrugamento, contração e descamação com perda de espinhos no colar peristômico e análise histopatológica evidenciou células do ceco alteradas, as glândulas vitelínicas com vacúolos e mudanças estruturais nas camadas musculares. Diminuição do conteúdo glicídico, principalmente no tecido conjuntivo, também foi observado. Considerando a predisposição à exposição a pesticidas agrícolas de N. squamipes infectado por E. paraensei, são necessários estudos para avaliar o impacto de tais resíduos frente aos helmintos e seus hospedeiros.

Freshwater Snail Diversity in Mae Lao Agricultural Basin (Chiang Rai, Thailand) with a Focus on Larval Trematode Infections

The aim of this study was to conduct a freshwater snail survey in Mae Lao agricultural basin to assess the diversity with a focus on habitat types and their larval trematode infections. Snails were collected and examined in 14 sites of Mae Lao agricultural basin from August 2016 to October 2017. A total of 1,688 snail individuals were collected and classified into 7 families, 8 genera, and 12 species. Snail diversity and habitat types were higher in rice paddies than irrigation canals and streams. The most abundant species was Bithynia siamensis siamensis, representing 54.6% of the sample. Three species of snails act as first intermediate host were found with cercarial infections. They were Filopaludina sumatrensis polygramma, B. s. siamensis, and Melanoides tuberculata. The cercariae were categorized into 7 types; echinostome, monostome, gymnocephalous, virgulate, parapleurolophocercous, pleurolophocercous and megalurous cercariae. Parapleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 41.2% of all infections in snails. Echinostome metacercariae infections were found in 6 snail species with 7.6% prevalence. In addition, the metacercaria of avian trematode, Thapariella sp. were found in Filopaludina spp. snails and B. funiculata with a prevalence of 0.5%. This is the first report for Thapariella metacercariae in the snail host, B. funiculata, and also confirmed that viviparid and bithyniid snails act as the second intermediate hosts of this trematode. This work will provide new information on the distribution and intermediate host of trematode in this area.

Infections with Zoonotic Trematode Metacercariae in Yellowfin Goby, Acanthogobius flavimanus, from Coastal Areas of Republic of Korea

To investigate the infection status of zoonotic trematode metacercariae in yellowfin goby, Acanthogobius flavimanus, from coastal areas of the Republic of Korea (Korea), we examined total 344 gobies from 21 localities with an artificial digestion method from 2013 to 2017. The metacercariae of Stictodora lari were most frequently detected in 45.3% goby from 7 localities, i.e., Taean-gun (Chungcheongnam-do), Gochang-gun (Jeollabuk-do), Muan-gun, Shinan-gun, Haenam-gun (Jeollanam-do), Hadong-gun and Goseong-gun (Gyeongsangnam-do). Their infection rates were 90.0%, 66.7%, 46.7%, 8.0%, 3.3%, 26.7%, and 86.7% and intensities were 1,090, 6.2, 1.6 1.0, 2.0, 2.0, and 7.2 metacercariae per fish infected respectively. Heterophyopsis continua metacercariae were found in 38.2% goby from 6 localities, i.e., Gochang-gun, Muan-gun, Shinan-gun, Gangjin-gun, Boseong-gun (Jeollanam-do) and Goseong-gun, and their intensities were relatively low, 1–21 metacercariae. Stictodora fuscata metacercariae were detected in 61.3% goby from 4 localities, i.e., Taean-gun, Gochang-gun, Hadong-gun and Goseong-gun. Their infection rates were 90.0%, 53.3%, 5.9%, and 73.3% and intensities were 1,081, 3.1, 3.0, and 10.2 metacercariae per fish infected respectively. Heterophyes nocens metacercariae were found in 55.0% goby from Muan-gun and Shinan-gun. Total 3 metacercariae of Isthmiophora hortensis were detected in 2 (8.0%) gobies from Shinan-gun. Total 15 metacercariae of Centrocestus armatus were detected in 5 gobies (33.3%) from Gyeongpo-ho (ho means lake) in Gangneung-si, Gangwon-do. The present study suggests that yellowfin goby, A. flavimanus, acts as the infection sources of zoonotic intestinal flukes in western and southern coastal areas than in eastern coastal areas of Korea.

Hypolobocera guayaquilensis (Decapoda: Pseudothelphusidae): A New Crab Intermediate Host of Paragonimus mexicanus in Manabí Province, Ecuador

To determine that Paragonimus sp. is actively transmitted in a tropical area of the Pacific region of Ecuador where human cases of pulmonary paragonimiasis have recently been documented, a total of 75 freshwater crabs were collected from 2 different streams in the Pedernales area of Manabí Province, Ecuador. All collected crabs were identified as Hypolobocera guayaquilensis based on morphological characteristics of the male gonopods. The hepatopancreas of each crab was examined by compressing it between 2 glass plates followed by observation under a stereomicroscope. Excysted Paragonimus metacercariae were detected in 39 (52.0%) crabs and their densities varied from 1 to 32 per infected crab. There was a positive relationship between crab size and metacercarial density. Sequences of the second internal transcribed spacer region of the ribosomal RNA gene of the Paragonimus metacercariae obtained in this study were identical to those of Paragonimus mexicanus deposited in the DDBJ/EMBL/GenBank database. Thus, the present study is the first to confirm that the crab species H. guayaquilensis is the second intermediate host of P. mexicanus in Manabí Province, Ecuador. Because this crab might be the possible source of human infections in this area, residents should pay attention to improper crab-eating habits related with a neglected parasitic disease, i.e., paragonimiasis.

Choledocystus elegans (Digenea: Plagiorchiidae) of Leptodactylus paraensis (Amphibia: Leptodactylidae) from the Brazilian Amazon / Choledocystus elegans (Digenea: Plagiorchiidae) de Leptodactylus paraensis (Amphibia: Leptodactylidae) da Amazônia brasileira

Abstract The trematodes are parasites of the several vertebrates including amphibians, however the knowledge about of the taxonomy these parasites is still confuse. The trematode Choledocystus elegans was found in the small intestine of the Leptodactylus paraensis in eastern Amazon and presents the following characteristics: several pointed tegumentary spines, papillae on the outer and inner edges of the oral and ventral suckers, a round, well-developed cirrus sac, a well-developed cirrus, oblique testicles, a ovary right side, uterine loops extending between the testicles, follicular vitellaria distributed throughout the body, starting at the genital pore region and caeca close the end of the body. For the first time, this study identified C. elegans parasitizing L. paraensis and describes morphological aspects never characterized using light and scanning electron microscopy.

Resumo Os trematodas são parasitas de vários grupos de vertebrados incluindo os anfíbios, contudo o que se conhece sobre a taxonomia destes parasitas ainda é confusa. O trematoda Choledocystus elegans foi encontrado no intestino delgado de Leptodactylus paraensis na Amazônia oriental e apresenta as seguintes características: vários espinhos pontiagudos no tegumento, papilas nas bordas externa e interna das ventosas orais e ventrais, bolsa do cirro bem desenvolvida contendo um cirro desenvolvido, testículos oblíquos, ovário destro, alças uterinas que se estendem entre os testículos, folículos vitelínicos distribuída por toda a lateral do corpo, começando ao nível do poro genital e cecos intestinais chegando até a região posterior do corpo do helminto. Pela primeira vez, este estudo identificou C. elegans parasitando L. paraensis e descreve aspectos morfológicos nunca caracterizados usando microscopia de luz comum e eletrônica de varredura.

Primer registro de Typhlocoelum cucumerinum (Trematoda: Typhlocoelidae) en Cairina moschata domestica (aves: Anatidae) en Colombia / First record of Typhlocoelum cucumerinum (trematode: Typhlocoelidae) in Cairina moschata domestica (birds: Anatidae) in Colombia / Primeiro registro de Typhlocoelum cucumerinum (Trematódeo: Typhlocoelidae) em Cairina moschata doméstica (aves: Anatidae) na Colômbia

Resumen: En el presente estudio se registra por primera vez para Colombia el trematodo Typhlocoelum cucumerinum (Rudolphi, 1809) en el pato criollo doméstico (Cairina moschata domestica). Se colectaron un total de 210 trematodos en 42 individuos adultos, 26 machos y 16 hembras. Se encontró una frecuencia parasitaria del 57,14 % y una intensidad parasitaria promedio de 8,75 parásitos por animal. Los resultados obtenidos demuestran la presencia del trematodo en ecosistemas acuáticos del departamento de Córdoba, Colombia.

Abstract: This study records for the first time in Colombia the presence of trematode Typhlocoelum cucumerinum (Rudolphi, 1809) in domestic Muscovy ducks (Cairina moschata domestica). A total of 210 trematodes were collected from 42 adult individuals, 26 males and 16 females. Parasitic frequency was 57.14% and mean parasitic intensity was 8.75 parasites per animal. Results show the presence of trematodes in aquatic ecosystems in the Department of Córdoba (Colombia).

Resumo: Neste estudo se registra pela primeira vez para a Colômbia o trematódeo Typhlocoelum cucumerinum (Rudolphi, 1809) no pato-do-mato (pato de Muscovy) doméstico (Cairina moschata doméstica). Coletaram-se um total de 210 trematódeos em 42 indivíduos adultos, 26 machos e 16 fêmeas. Se encontrou uma frequência parasitária do 57,14 % e uma intensidade parasitária em média de 8,75 parasitas por animal. Os resultados obtidos demonstram a presença do trematódeo em ecossistemas aquáticos do departamento de Córdoba, na Colômbia.