High Prevalence of Human Liver Infection byAmphimerusspp. Flukes, Ecuador

Abstract

Amphimerus spp. flukes are known to infect mammals, but human infections have not been confirmed. Microscopy of fecal samples from 397 persons from Ecuador revealed Opisthorchiidae eggs in 71 (24%) persons. Light microscopy of adult worms and scanning electron microscopy of eggs were compatible with descriptions of Amphimerus spp. This pathogen was only observed in communities that consumed undercooked fish.

High Prevalence of the Liver Fluke Amphimerus sp. in Domestic Cats and Dogs in an Area for Human Amphimeriasis in Ecuador

“…These communities are the same as those studied previously, showing the resident Chachi having a high prevalence of infection with Amphimerus sp. [ 10 ]. They live in remote villages where the only way to reach the communities are by boat along the river; the source of their water is mainly from rivers and streams and is consumed untreated.…”

“…sinensis and Opisthorchis spp., cats and dogs are the most important animal reservoirs for human infection [ 2 , 3 , 17 , 18 ]. However, it is currently unknown whether domestic animals may act as a definitive and/or reservoir host for human transmission in the recently reported focus of infection in Ecuador [ 10 ]. Given the similarities between C .…”

“…The indigenous group, Chachi, who live along the Rio Cayapas and its tributaries in the north-western coastal rainforest of Ecuador, have been shown to have a high prevalence of infection (15.5% to 34.1%) with Amphimerus sp. [ 10 ]. Afro-Ecuadorian and mestizo populations living in separate communities but along the same rivers were not found to be infected [ 10 ].…”

“…[ 10 ]. Afro-Ecuadorian and mestizo populations living in separate communities but along the same rivers were not found to be infected [ 10 ]. The solo infection of the Chachi population was postulated to be related to their cultural tradition of eating smoked fish and food sharing [ 10 , 11 ].…”

Zoonotic Trematodiasis

“…A number of immunological procedures based on hemagglutination, immunofluorescence, and indirect enzyme-linked immunosorbent assay test have been reported as useful both during acute and chronic stages of most trematodiasis [48]. In spite of the success of immunological procedures, most of them rely on the identification of circulating antibodies and are therefore indirect procedures [49]; additionally, blood-circulating antibodies may show high titers long after the elimination of the parasites [53].…”