ABSTRACT
Abstract Schistosomiasis is a neglected disease that affects millions of people around the world, being common in the state of Maranhão. A total of 225 rodents of the Holochilus sciureus species from the Western Lowland Maranhão were studied, of which 144 animals (64%) exhibited Schistosoma eggs in their feces samples. Macroscopic lesions characterized as well-defined whitish areas on the liver and spleen surfaces were observed. Histopathological examination revealed multifocal granulomas in the esophagus, liver, spleen, pancreas and duodenum, with structures compatible with Schistosoma mansoni eggs, as well as severe hepatic micro-vacuolar degeneration, multifocal and coalescent, with proliferation of random bile ducts and associated epithelial hyperplasia to areas of fibrosis. Adult forms of the parasite were observed in the blood vessels of the portal space. The lungs exhibited moderate and diffuse interstitial pneumonia with intralesional S. mansoni eggs. In the kidneys, hyaline cylinders were observed in the pelvis and diffuse hemorrhage. In conclusion, H. sciureus displays a pathological picture similar to human being. This rodent plays a role as sentinel in Baixada Maranhense.
Resumo A esquistossomose é uma doença negligenciada que afeta milhões de pessoas em todo o mundo, sendo comum no estado do Maranhão. Um total de 225 roedores da espécie Holochilus sciureus da Planície Ocidental do Maranhão foram estudados, dos quais 144 animais (64%) apresentaram ovos de Schistosoma em suas fezes. Lesões macroscópicas caracterizadas como áreas esbranquiçadas bem definidas nas superfícies do fígado e baço foram observadas. O exame histopatológico revelou granulomas multifocais no esôfago, fígado, baço, pâncreas e duodeno, com estruturas compatíveis com ovos de Schistosoma mansoni, degeneração micro-vacuolar hepática grave, multifocal e coalescente, com proliferação de ductos biliares aleatórios e hiperplasia epitelial associada a áreas de fibrose. Formas adultas do parasito foram observadas nos vasos sanguíneos do espaço portal. Os pulmões exibiram pneumonia intersticial moderada e difusa com ovos de S. mansoni intralesionais. Nos rins, foram observados cilindros hialinos na pelve e hemorragia difusa. Em conclusão, H. sciureus apresenta um quadro patológico semelhante ao ser humano. Este roedor desempenha um papel de sentinela na Baixada Maranhense.
Subject(s)
Animals , Schistosoma mansoni/isolation & purification , Schistosomiasis mansoni/veterinary , Sigmodontinae/parasitology , Parasite Egg Count , Schistosomiasis mansoni/parasitology , Schistosomiasis mansoni/pathology , Feces/parasitologyABSTRACT
Abstract Litomosoides chagasfilhoi, originally described by Moraes Neto, Lanfredi & De Souza (1997) parasitizing the abdominal cavity of the wild rodent, Akodon cursor (Winge, 1887), was found in the abdominal cavity of Nectomys squamipes (Brants, 1827), from the municipality of Rio Bonito, Rio de Janeiro State, Brazil. This study led to addition of new morphological data and a new geographical distribution for this filarioid in Brazil. Several characters were detailed and emended to previous records of L. chagasfilhoi in N. squamipes, and confirming the original description in A. cursor: buccal capsule longer than wide with walls thinner than the lumen, right spicule slightly sclerotized, with membranous distal extremity slender, with a small tongue-like terminal portion, left spicule with handle longer than the blade, whose edges form large membranous wings folded longitudinally.
Resumo Litomosoides chagasfilhoi, originalmente descrito por Moraes Neto, Lanfredi & De Souza (1997) parasitando a cavidade abdominal do roedor silvestre Akodon cursor (Winge, 1887), foi encontrado na cavidade abdominal de Nectomys squamipes (Brants, 1827), no município de Rio Bonito, Estado do Rio de Janeiro, Brasil. Este estudo propiciou a adição de novos dados morfológicos e uma nova distribuição geográfica deste filarídeo no Brasil. Vários caracteres foram detalhados e adicionados ao registro anterior de L. chagasfilhoi em N. squamipes, e confirmando a descrição original em A. cursor: cápsula bucal mais alta do que larga com paredes mais finas que o lúmen, espículo direito ligeiramente esclerotizado, com extremidade distal membranosa mais estreita, com uma pequena porção terminal em forma de língua, espículo esquerdo com cabo mais longo do que a lâmina, cujas bordas formam grandes asas membranosas dobradas longitudinalmente.
Subject(s)
Animals , Rodent Diseases/parasitology , Sigmodontinae/parasitology , Filarioidea/anatomy & histology , Rodentia , Brazil , Filarioidea/ultrastructureABSTRACT
To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.
Subject(s)
Animals , Male , Angiostrongylus/physiology , Heart/parasitology , Host Specificity/physiology , Lung/parasitology , Rodent Diseases/parasitology , Sigmodontinae/parasitology , Argentina , Host-Parasite Interactions/physiology , Lung/pathology , Myocardium/pathology , Rodentia/parasitology , Sampling Studies , Species SpecificityABSTRACT
Ixodes schulzei Aragão & Fonseca is an endemic tick to Brazil and has already been reported in the northern (State of Rondonia), southeastern (States of Minas Gerais, Rio de Janeiro and São Paulo) and southern (State of Santa Catarina) regions, always found in association with the water rat Nectomys squamipes (Brandt). This communication records the first occurrence of this tick species in the State of Parana, southern region of Brazil, and it constitutes its first report on Akodon montensis (Thomas) and Oryzomys russatus (Wagner) hosts.
Ixodes schulzei Aragão & Fonseca é um carrapato endêmico do Brasil e já foi relatado nas regiões Norte (estado de Rondônia), Sudeste (estados de Minas Gerais, Rio de Janeiro e São Paulo) e Sul (estado de Santa Catarina), tendo sido encontrado sempre em associação com o rato d'água Nectomys squamipes (Brandt). Esta comunicação registra a primeira ocorrência dessa espécie de carrapato no estado do Paraná, região Sul do Brasil e constitui o primeiro relato de Akodon montensis (Thomas) e Oryzomys russatus (Wagner) como hospedeiros.
Subject(s)
Animals , Female , Arvicolinae/parasitology , Ixodidae/physiology , Sigmodontinae/parasitology , BrazilABSTRACT
The objective of this research was to study infestation parameters and indexes of ectoparasites associated with each sex of the wild rodents Oligoryzomys flavescens (Waterhouse) andAkodon azarae (Fischer) in the Punta Lara wetlands, Argentina. A trend towards higher mean abundance (MA) and ectoparasite specific richness was observed in males of O. flavescens whereas those values were similar for both A. azarae sexes. The prevalence of the following ectoparasites was significantly higher on males (P < 0.05): Mysolaelaps microspinosus Fonseca (65.2 percent) and Hoplopleura travassosi Werneck (73.9 percent) on O. flavescens, and Ixodes loricatus Neumann (71.4 percent) on A. azarae. Only H. travassosi mean abundance was significantly higher on males (MA = 44.1). Since I. loricatus and Hoplopleura spp. are involved in the transmission of pathogens that cause diseases in animals and humans, and whose reservoirs are rodent hosts, these results are epidemiologically important.
Subject(s)
Animals , Female , Male , Ectoparasitic Infestations/veterinary , Rodentia/parasitology , Argentina , Sex Factors , Sigmodontinae/parasitologyABSTRACT
The wild rodent, Abrothrix olivaceus, is a widespread species in Chile using different habitats troughout the territory. Its helminthfauna has been partially studied in wild enviroments in Chile. In this work five nematodes and one species ofcestode were found. Three of them are first record in this host: Syphacia obvelata, Physaloptera calnuensis and Heterakis spumosa, and this last one, is first record in Chile. It is suggested that one structuring factor is the locality: one of the three localities studied had more mean abundance and prevalence in two parasites species and as a component community. It is also suggested that other structuring factor of this helminth community is the introduction of parasites from foreign species. This is the first study of its helminthes in sub-urban localities and in the Region Metropolitana.
El ratón oliváceo (Abrothrix olivaceus) se distribuye ampliamente a lo largo de Chile abarcando diversos ambientes. Su helmintofauna ha sido parcialmente estudiada en diversas áreas silvestres del país. En este trabajo se encontraron cinco especies de nemátodes y un cestode. Tres de estas especies parásitas se registran por primera vez en este hospedador: Syphacia obvelata, Physaloptera calnuensis y Heterakis spumosa, y esta última se registra por primera vez en Chile. Se sugiere que uno de los factores estructurantes es la localidad de muestreo: una de las tres localidades estudiadas presentó significativamente mayor abundancia media y prevalencia en dos especies de parásitos y como comunidad componente. Se sugiere que otro factor estructurante es la introducción de parásitos desde especies exóticas. Éste es el primer estudio de la helmintofauna de este roedor en localidades suburbanas y en la Región Metropolitana.
Subject(s)
Animals , Helminthiasis, Animal/epidemiology , Helminths/isolation & purification , Helminths/growth & development , Sigmodontinae/parasitology , Chile , Rodent Diseases/parasitology , Helminths/anatomy & histology , Helminths/classification , Prevalence , Species Specificity , Urban AreaABSTRACT
The water rat, Nectomys squamipes, closely involved in schistosomiasis transmission in Brazil, has been found naturally infected simultaneously by Schistosoma mansoni and Echinostoma paraensei. Laboratory experiments were conducted to verify parasitic interaction in concurrent infection. It was replicated four times with a total of 42 water rats and essayed two times with 90 mice pre-infected with E. paraensei. Rodents were divided into three groups in each replication. A wild strain recently isolated from Sumidouro, RJ, and a laboratory strain of S. mansoni from Belo Horizonte (BH) was used. Rats infected with E. paraensei were challenged 4 weeks later with S. mansoni and mice 2 or 6 weeks after the infection with S. mansoni. Necropsy took place 8 weeks following S. mansoni infection. The N. squamipes treatment groups challenged with S. mansoni RJ strain showed a significant decrease (80 and 65 percent) in the S. mansoni parasite load when compared with their respective control groups. There was a significant change or no change in the hosts challenged with the BH strain. The persistence time of E. paraensei within host was extended in relation to control groups, with a consequent enhancement of the number of recovered worm. An E. paraensei strain-specific influence on S. mansoni parasitism is reported. This paper presents some experimental data about this interaction in N. squamipes and Mus musculus
Subject(s)
Animals , Male , Female , Mice , Echinostoma/isolation & purification , Schistosoma mansoni/isolation & purification , Sigmodontinae/parasitology , Host-Parasite Interactions/physiology , Schistosoma mansoni/embryology , Schistosoma mansoni/pathogenicity , Schistosomiasis mansoni/transmissionABSTRACT
El interés de los investigadores por el uso del roedor sigmodon hispidus como modelo experimental ha incrementado en los últimos años. Por ello y dado el poco conocimiento de las poblaciones de parásitos de las ratas de la región estudiada, se analizó la prevalencia de endoparásitos en ratas procedentes de zona de cultivo de piña de Alajuela. A 74 ratas capturadas se les registró el sexo, y a las hembras se les determinó su estado de gravidez. Se realizó una disección completa de los animales con revisión meticulosa de todos los órganos. Los contenidos intestinales fueron analizados al fresco y a los que resultaron positivos por ooquistes de eimeria sp., fueron colocados en una solución de dicromato de potasio al 2,5 por ciento para la maduración de los ooquistes. El 51,2 por ciento de las ratas estaban parasitadas por protozoarios y el 100 por ciento por helmintos, (nemátodos). Las prevalencias encontradas fueron: longistriata sp, 95,9 por ciento, angiostrongylus costaricensis 42,3 por ciento; eimeria sigmodontis 28,4 por ciento; trichimonas sp 23,0 por ciento; eimeria tuskegeensis 10,8 por ciento; eimeria roperi 5,4 por ciento y eimeria webbae 1,4 por ciento. La prevalencia de protozoarios fue menor de la que ha sido informada en estudios anteriores, posiblemente porque la zona analizadas está en vías de desarrollo urbano-industrial. La prevalencia de A. costaricensis, agente etiológico de la angiostrongiliasis abdominal y de longistriata sp fue muy elevada. Se notó una mayor prevalencia de protozoarios en hembras no embarazadas (60,5 por ciento) que en las embarazadas lo cual pareciera indicar una mayor resistencia de las madres ante estos parásitos en los períodos de desarrollo del feto
Subject(s)
Animals , Rats , Intestinal Diseases, Parasitic/epidemiology , Rats/parasitology , Sigmodontinae/parasitology , Angiostrongylus/isolation & purification , Crop Production/parasitology , Eukaryota/isolation & purification , Helminths/isolation & purificationABSTRACT
Um número de casos angiostrongilíase abdeominal tem sido detectado no sul do Brasil. O principal hospedeiro do Angiostrongylus costaricensis na América Central, o rato do algodäo (Sigmodon hispidus), näo ocorre na América do Sul, exceto no norte do Peru, Colômbia e Venezuela. Foram realizadas capturas na área endêmica do Rio Grande do Sul (RS), visando identificar hospedeiros para obtençäo de vermes em laboratório e produçäo de antígeno. Pela primeira vez no Brasil foi constatada a infecçäo em roedores: Oryzomys nigripes e Oryzomys ratticeps. O nigripes é um roedor silvestre de pequeno porte e parece ser o principal hospedeiro definitivo do A. costaricensis na regiäo serrana do RS