Echinococcus granulosus complex infection in wild boar hunters and auxiliary hunting dogs

Abstract

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu lato (s.l.) is a zoonotic neglected tropical disease endemic in Italy, which perpetuates in several intermediate hosts, including wild boars, and dogs as definitive hosts. People living in rural and livestock-raising areas are exposed to E. granulosus s.l. infection, as well as people leading outdoor activities in endemic regions. Therefore, this study was designed to assess the exposure to Echinococcus spp. in wild boar hunters, the role of their hunting dogs as parasite reservoirs, along with hunter's knowledge on the infection risk.

From December 2022 to May 2023, wild boar hunters (n = 122) from southern Italy were recruited on volunteer basis for blood and serum sampling and a questionnaire enquiring socio-demographic, anamnestic data and knowledge on CE was also filled out. Sera were tested for Echinococcus spp. IgG by a commercial enzyme-linked immunosorbent assay (Euroimmun ELISA®, Germany). In addition, faecal samples from their hunting dogs (n = 208) were screened for Taeniidae eggs by parasitological and molecular approaches.

Overall, six (4.9 %) hunters scored either positive or borderline for IgG anti-Echinococcus spp., of which one presented a calcified hepatic cyst at abdominal ultrasonography. In addition, 6.3 % Taeniidae prevalence was recorded in faecal samples (13/208) of hunting dogs, and E. granulosus sensu stricto (s.s.) was molecularly identified in two samples. The statistical analysis revealed the risk factors (odds ratio > 1, p < 0.05) associated with parasitic exposure, including the hunter geographical provenience, and the presence of animals around or in the house.

The E. granulosus s.l. exposure of hunters herein detected, coupled with the parasite molecular positivity of their hunting dogs and the limited awareness on Echinococcus spp. life cycle/infection risk, highlight the relevance to promote health surveillance and educational programs within the hunting category, for minimizing the cestode circulation in the wildlife-urban premises.