A Cross-Sectional Study to Detect Cystic Echinococcosis in Añatuya, Santiago Del Estero (Argentina)

Abstract

Cystic echinococcosis (CE) is endemic in Argentina, and approximately 30% of the national territory has characteristics appropriate for the development of the zoonotic domestic cycle of this disease. This community-wide study was implemented in rural areas of Añatuya, Santiago del Estero (northern Argentina) to determine the presence of Echinococcus granulosus sensu lato in the definitive host (dogs) and the presence of CE in humans. Infection data from dogs were obtained through the collection and analysis of fecal samples; these were processed through sedimentation/flotation techniques and PCR. The presence in humans was determined by ultrasound (US) and serology (ELISA confirmed by Western Blot—WB) in the Miel de Palo settlement. A standardized questionnaire was used to investigate potential risk factors for CE; more than half of the studied population carried out activities that favor the maintenance of the cycle. The prevalence of E. granulosus s.l. in dogs from 10 rural settlements, confirmed by PCR, was 4.7% (32/678). The results of the US and serology screening showed a human prevalence of 0.55% (1/183) in Miel de Palo. This prevalence increased to 4.9% (9/183) if imaging-negative but serology-positive (ELISA+WB) individuals are included, as per national guidelines. One of the participants with CE, confirmed by US, was less than 15 years old, which evidences the presence of active transmission. A comprehensive multidisciplinary approach, taking into consideration social, behavioral, sanitary, and environmental aspects intimately tied to the parasite cycle, is needed.