Molecular characterization of Echinococcus granulosus in a hyperendemic European focus, the Republic of Moldova.

Abstract

Cystic echinococcosis is a zoonosis caused by the tapeworm Echinococcus granulosus sensu lato. The lifecycle of the parasite is mainly domestic, requiring dogs as definitive hosts and livestock species as intermediate hosts. Although human cystic echinococcosis is a high public health priority in the Republic of Moldova, the rare animal data available concerns only infection in cattle. A preliminary slaughterhouse survey was conducted to assess prevalence and perform the first molecular characterization of E. granulosus sensu lato in sheep and cattle. For the survey, 40 sheep and 19 cattle were inspected. Very high prevalence in sheep (82.5%) and in cattle (78.9%) was found. Molecular analyses identified genotypes G1 and G3 of E. granulosus sensu stricto in all the liver and lung samples. Based on the concatenated sequences of cox1 + nad3 (701 bp), 23 different haplotypes were obtained. Mixed infections by different haplotypes/genotypes were frequently identified in both sheep and cattle. The relatively high (20.0%) cyst fertility observed in cattle argues for the potential contribution of cattle to the lifecycle of E. granulosus sensu stricto, unlike previous observations in Europe. The hyperendemic situation of Moldova can be explained by a high majority of animals slaughtered at home usually without veterinary inspection. Further extensive slaughterhouse surveys with molecular identification also involving pigs and goats are needed to obtain a better overview of the epidemiological situation of E. granulosus sensu lato in this hyperendemic focus in the Republic of Moldova.