The population density of Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) an intermediate host of Fasciola hepatica (Linnaeus, 1758), in the Caparaó microregion, ES, Brazil / Densidade populacional de Lymnaea columella (Say, 1817) (Mollusca, Lymnaeidae) hospedeiro intermediário de Fasciola hepatica (Linnaeus, 1758) na Microrregião do Caparaó, ES, Brasil

Abstract The aim of this study was to monitor the population density of Lymnaea columella, an intermediate host of Fasciola hepatica, in various aquatic habitats and in drinking water in the area of the Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo, on Caparaó Microregion, municipality of Alegre, state of Espírito Santo, Brazil. Monthly samplings were performed at certain points between drainage areas and drinking water in cattle and goat production systems during the years 2010 to 2013. The mean temperature, precipitation and the frequency of samples of L. columella were analysed graphically according the monthly average during the study period. A total of 2,038 molluscs were collected, 1558 of which were L. columella, that predominated in all sampled points. The highest average of specimens observed for L. columella was in the years 2010 and 2013 (51.0), and occurred decreased in 2011 (19.8). The temperature and precipitation averaged is 23.7 °C and 141 mm/year, respectively. Rainfall peak occurred in March (2011, 2013) and November (2012), during these periods the population of L. columella growth. There was no significant difference in the relationship between the specimens observed with seasons (dry-wet), thus the population of L. columella remained stable and can be found throughout the year.

Resumo O objetivo deste estudo foi acompanhar a variação da densidade populacional de Lymnaea columella, hospedeiro intermediário de Fasciola hepatica, em diferentes tipos de coleções hídricas e bebedouros na área do Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo, na microrregião do Caparaó, município de Alegre, estado do Espírito Santo, Brasil. Foram realizadas coletas mensais em pontos determinados entre áreas de drenagem e bebedouros de animais nos setores de bovinocultura e caprinocultura durante os anos de 2010 a 2013. As médias de temperatura, precipitação e a frequência de exemplares de L. columella foram analisadas graficamente de acordo com a média mensal ao longo do período avaliado. Foram coletados 2.038 moluscos, sendo 1558 de L. columella, espécie predominante em todos os pontos amostrados. A maior média de espécimes observadas para L. columella foi nos anos de 2010 e 2013 (51,0), ocorrendo um decréscimo em 2011 (19,8). A temperatura apresentou média de 23,7°C e precipitação de 141 mm/ano. Picos de precipitação ocorreram em Março (2011, 2013) e Novembro (2012), nestes períodos foi observado aumento populacional de L. columella. Não houve diferença significativa na relação entre as espécimes observadas com as estações do ano (seca-chuvosa), dessa forma, a população de L. columella se mostrou estável, podendo ser encontrada durante todo ano.

Distribution and factors associated with Fasciola hepatica infection in cattle in the south of Espírito Santo State, Brazil

Fasciolosis is a disease that affects the liver parenchyma and bile ducts of numerous animals, including humans, which causes economic losses and threatens public health. The present work aimed at reporting the distribution and factors connected with Fasciola hepatica infection in cattle in ten municipalities in southern Espírito Santo, Brazil, between 2008 and 2009. During this period, 50 rural properties in ten cities were analyzed and fecal samples from 10 percent of the cattle on each farm were collected. Of the 717 samples analyzed, 154 (21.33 percent) presented Fasciola hepatica eggs. As for the 50 rural properties studied, 32 (64 percent) had animals positive for fasciolosis. Throughout the evaluation, it was observed that 42 (84 percent) rural properties had flooded areas, 33 (66 percent) were located at altitudes less than 226 meters, in 36 (72 percent) mollusks were found, 47 (94 percent) had other definitive hosts (horses, sheep, goats) and 25 (50 percent) had previous cases of bovine fasciolosis. The present results showed a high rate of bovine fasciolosis in the analyzed region whereas infected animals are present in all the municipalities. Based on statistical analysis, it was concluded that there was an association between the presence of flooded areas and other definitive hosts in rural properties where bovine fasciolosis was detected.