Molecular Detection of Echinococcus granulosus Sensu Stricto in Environmental Dog Faecal Samples from the Magallanes Region, Patagonia, Chile

Echinococcus granulosus is endemic in the Magallanes region and other areas of Chile. After a successful control programme implemented between 1979 and 2004, dogs' prevalence decreased from 70% to 0.5%. Since the end of the programme, no prevalence study of canine echinococcosis has been performed in this region. Dog faecal samples were collected from epidemiological units for DNA isolation and polymerase chain reaction (PCR) to detect E. granulosus. In addition, dog owners were required to answer a questionnaire for a risk factor analysis. We collected 1069 environmental dog faecal samples from 267 urban, 241 periurban, and 61 rural epidemiological units. E. granulosus was found in 11/61 (18%) and 1/241 (0.4%) epidemiological units from rural and periurban areas, respectively. The Ultima Esperanza province showed the highest prevalence with eight out of 16 units with faeces positive to E. granulosus showing a main spatial cluster of canine echinococcosis. None of the risk factors investigated showed a statistical significance with positive units. This study shows the active transmission of the parasite in the Magallanes region, especially in the Ultima Esperanza province, with a possible re-emergence of the parasite. Further studies focusing on the incidence in humans are required together with the reestablishment of the compulsory deworming of dogs.