Fasciola hepatica en ganado bovino de carne en Siquirres y lesiones anatomo-histopatológicas de hígados bovinos decomisados en mataderos de Costa Rica

摘要

This study was carried out in order to determine Fasciola hepatica infection in a farm dedicated to fattening beef cattle in Siquirres, Limón province; also, to characterize the most common lesions in parasitized bovine livers in 3 slaughterhouses in Costa Rica. Fecal samples were collected from 577 zebu bovines aging between 6 months and 2.5 years, from August 2005 to August 2006. Each sample was analyzed by the fecal sedimentation technique. To identify the species involved in parasite transmission, a search and collection of mollusks in the farm was also done. Besides, samples of infected bovine livers were collected in 3 slaughterhouses of the Central Valley, for histopathologic analysis. F. hepatica was diagnosed in 67 (11.3%) out of 577 animals, with the highest percentage of infection in August 2005 (31.6%) and August 2006 (26.2%). Animals aging between 18 and 24 months showed higher infection frequency (19.4%) than those between 12 and less than 18 months of age (2.4%). Thiara tuberculata, the snail specie found in the farm, was not identified as vector of F. hepatica. Main lesions in sampled infected livers were mild atrophy of hepatic lobes, tissue hardening, biliary ducts thickening with calcification, mucous material and adult parasites. Histologically, lesions were necrotic colangiohepatitis with dystrophic calcium deposits, together with biliary ducts hyperplasia. Based in these results, it was determined the presence of F. hepatica in bovines in this farm and in the region, with a marked infection increase in the rainy season, besides the collateral finding of Paramphistomum spp.