Clinostomum sp. (Digenea: Clinostomidae) and Ascocotyle sp. (Digenea: Heterophyidae): metacercariae with zoonotic potential in fishes from Tramandaí­­ River basin, southern Brazil

Abstract

 The helminths belonging to the class Trematoda have great importance in ichthyoparasitology, and the subclass Digenea includes parasites with zoonotic potential. The family Heterophyidae is responsible for the heterophyiasis and, in Brazil, this disease is caused by the trematode genera Ascocotyle (Phagicola), commonly known as phagicolosis, both related to the fish-to-birds/mammals cycle. Clinostomum (belonging to the family Clinostomidae) has its larval stage in fish musculature and piscivorous birds as definitive hosts. It may parasitize humans accidentally, causing parasitic laryngopharyngitis and death by asphyxia. This study aims to quantify the presence of digenetic Heterophyidae and Clinostomidae parasites with zoonotic potential in fish from the Tramandaí­­ River basin, in the state of Rio Grande do Sul, Brazil. The fish were purchased from fishermen from Terra de Areia/RS, from July 2016 to May 2017. The search for parasites was carried out by performing a necropsy on the fish. The digenetic parasites were preserved, stained and mounted on microscope slides for identification. Parasitological indices were calculated. Astyanax spp. Were positive for Ascocotyle whereas Geophagus brasiliensis was infected by Clinostomum sp. Therefore, the results suggest a risk of infection to the consumer population in the region.