The pig strain of Echinococcus granulosus in humans: a neglected issue?

摘要

Echinococcus granulosus has several strains with distinct morphological, epidemiological and clinical characteristics [1-3]. Cystic echinococcosis (CE) in humans is commonly caused by the sheep strain (G1), and prevention of the dog-sheep-dog transmission has attracted attention from veterinarians and public health specialists. A possibility of occurrence of the pig strain in humans is considered infrequently (e.g. it has not been noted in the recent review on CE in Mediterranean countries [4]). However, there are countries or at least regions where the pig strain of E. granulosus (G7,G9) is present or even dominates. During the years 1994-2001, in the Poznan region, Poland, 16 patients with CE had the strain of E. granulosus examined by molecular techniques [5,6]. All 16 patients were infected by the pig strain only. In the study area, the prevalence of E. granulosus infection in pigs was 13.7% at slaughter, and one out of four dogs was found infected at autopsy. Two years after a treatment with praziquantel, offered free to all dogs in private farms supplying infected pigs, the prevalence of echinococcosis in pigs at slaughter dropped down to 0.5% [6]. Our experience on control of CE can be useful for the countries, where pigs are still raised in small private farms such as in Austria, France, Greece, Italy, Slovakia, Spain and Ukraine.