Occurrence of Echinococcus vogeli in Cuniculus paca from the Western Amazon and its implications for the health of local traditional communities

Abstract

Consumption of wild animals, especially the paca (Cuniculus paca), is a common practice among traditional communities. This rodent represents the main intermediate host for Echinococcus vogeli, the etiological agent of human polycystic echinococcosis, which is a zoonosis of growing public health concern in the region. This study aimed to investigate the occurrence of E. vogeli in livers of pacas slaughtered and consumed by resident traditional communities in the Western Brazilian Amazon. The research was observational and descriptive, conducted between May 2022 and December 2023 in traditional communities of Sena Madureira and Rio Branco (State of Acre, Brazil). Household interviews were performed to characterize hunting practices and dog management, along with the collection of paca livers for parasitological and molecular analysis (amplification and sequencing of a fragment of the cox1 mtDNA). Of the 78 families interviewed, 78% reported the practice of subsistence hunting. A total of 194 dogs were recorded, 83% of which actively participated in hunting activities, and 80% often consumed raw viscera, mostly from pacas. Among the 23 livers analyzed, 48% contained hydatid cysts (ranging from 1 to 13 cysts per liver), with E. vogeli infection confirmed based on morphology and PCR. The findings suggest that feeding dogs with raw viscera may facilitate the establishment of the domestic transmission cycle of E. vogeli, thereby increasing the risk of zoonotic infection. The close contact between humans, dogs, and infected paca livers highlight the urgent need for epidemiological surveillance and educational strategies aiming at the prevention of echinococcosis in endemic areas.