Frequency, Geospatial Distribution, and Subspecies of Echinococcus granulosus Identified in Dog Stool in Urban Public Spaces of an Endemic Area in Cusco, Peru

The impact of environmental contamination with Echinococcus granulosus eggs on the transmission to humans remains unknown. The control of free-roaming and stray dogs is a public health problem in urban and periurban areas of the Cusco region, such as the city of Sicuani in the Canchis province. Nearly one in four human cystic echinococcosis cases referred to tertiary hospitals in the Cusco region of Peru is referred from the Sicuani district. This study sought to determine the frequency and spatial distribution of E. granulosus DNA in dog stool collected within urban public spaces of Sicuani. We conducted a cross-sectional study using a systematic 100 × 100-meters2 grid-based sampling design. Dog stools located at the closest point to georeferenced square vertices were selected for collection. Epidemiologically relevant locations, such as abattoirs and food markets, were also georeferenced. Nineteen (5.5%) of 347 collected samples tested positive for E. granulosus DNA. Polymerase chain reaction (PCR)-positive stools were located at a shorter median distance than negative stools to abattoirs (564 versus 1,292 meters, respectively, P <0.01). Northern Sicuani, an area where informal slaughtering is performed, was identified as a hot spot for PCR-positive stools. The sequence analysis of the PCR products of positive samples closely aligned with sequences of E. granulosus sensu stricto (G1) with close phylogenetic relationship. Our field study revealed that E. granulosus PCR-positive dog stools were associated with spatial proximity to abattoirs. Interventions to decrease E. granulosus infections among dogs, particularly around abattoirs, may decrease the potential environmental contamination with infective stages.