Gastrointestinal Helminths in Brown Bears in Erzurum, Türkiye: Biological Bridge, a Threat to Humans
TL;DR
It is suggested that bears may act as reservoirs for parasitic agents, playing an active role in the persistence of pathogens in the environment and their transmission to different hosts.
Abstract
Changes in land use, habitat fragmentation, and global climate fluctuations are reshaping pathogen circulation dynamics by increasing the permeability of the interface among wildlife, domestic animals, and humans. In this context, wild mammals play a crucial role as natural reservoirs for parasites and sources of environmental contamination. The primary aim of this study is to microscopically and molecularly identify gastrointestinal helminth eggs detected in bear fecal samples, as well as adult parasites found in two dead bears. A total of 333 fecal samples were collected from four locations in Erzurum, Türkiye, and examined microscopically; helminth eggs were further identified by molecular methods. Two dead bears were examined post-mortem for adult parasites. Baylisascaris transfuga (23.7%), Uncinaria stenocephala (3%), and Dicrocoelium sp. (19.5%) were detected in the 333 fecal samples collected from four locations. Furthermore, B. transfuga (in both animals), U. stenocephala (in one animal), and D. dendriticum (in one animal) were identified following post-mortem examinations. This study suggests that bears may act as reservoirs for parasitic agents, playing an active role in the persistence of pathogens in the environment and their transmission to different hosts. The findings of this study need to be examined from a One Health perspective, which focuses on biological transmission networks within ecosystems rather than on infection foci alone, to assess risks to public and animal health.