Dogs as reservoirs of Echinococcus spp. tapeworms and relevance for transmission to humans

Abstract

Objectives: Dogs are definitive hosts for Echinococcus spp. tapeworms. To assess the relevance of hunting and stray dogs as reservoirs of Echinococcus spp. eggs, which are infective for humans, feces samples were collected from several locations in Serbia with a confirmed presence of Echinococcus spp. in other animals. None of the dogs received anticestodal treatment prior to feces collection. Materials and methods: Taeniid eggs were isolated using a combined flotation and mesh filtration technique. Total gDNA was extracted from the collected eggs and multiplex nested PCR, based on detection of specific Cox1 sequences of E. multilocularis, E. granulosus and E. canadensis, was performed. Results: Thus far, n = 30 samples of hunting dog and n = 120 samples of stray dog feces were collected. Echinococcus spp. eggs were not present in any of the hunting dog samples. Further molecular screening for other cyclophillidean tapeworms revealed two positive dogs. Conclusion: Despite the absence of regular anticestodal treatment and distinct possibility of exposure to Echinococcus spp., none of the hunting dogs were shedding tapeworm eggs. These preliminary findings suggst that hunting dogs may not be relevant reservoirs of Echinococcus spp. for human infection. Processing of additional samples is underway.