Hunting and Stray Dogs as Reservoirs of Echinococcus Species

In Serbia, human echinococcosis cases are predominantly diagnosed as the cystic form, caused by Echinococcus granulosus sensu lato (s. l.) complex tapeworms. Alveolar echinococcosis, a more severe disease caused by Echinococcus multilocularis, emerged recently. Domestic dogs have been implicated in the transmission of E. granulosus sensu stricto G1/3 to humans. In an ongoing screening of definitive hosts for the presence of Echinococcus spp. to discover reservoirs of E. multilocularis, fecal samples of hunting (n = 29) and stray dogs (n = 66) were examined. Taeniid eggs were collected using flotation and mesh filtration. The presence of Cyclophyllidea, E. granulosus s. l. and E. multilocularis DNA was detected by specific PCR assays. In total, 60% of the fecal samples contained cyclophyllidean DNA, while Echinococcus spp. DNA was detected in 7.4% of the samples. E. canadensis G6-8,10 DNA was present in 4.2% and E. multilocularis in 3.2% of the samples. E. multilocularis DNA was detected only in stray dog feces, suggesting that strays are a reservoir and possibly an important link in the transmission chain. To the best of our knowledge, this study provides the first molecular identification of Echinococcus spp. in dogs in Serbia.