ABSTRACT
The imago stage of Echinococcus multilocularis development (prior to maturation of parasite oocysts) has been described in the intestine of golden hamsters infected by parenteral penetration of an Alveococcus agent and given hydrocortisone subcutaneously for 3 days before the infection and on the day of the infection, mean total drug dose being about 250 mg/kg. The number of helminths developed on days 8-35 of postinvasion ranged from 432 to 1863, their length was 1.0 to 4.0 mm and the number of segments did not exceed 2. Oocyst maturation was noted on day 20 of postinvasion. High oocyst invasiveness was confirmed by a biological test on 32 cotton rats aged 1-1.5 months who were administered parenterally 2-3 helminths containing 86 to 284 oocysts. All the rats died of severe hepatic alveococcosis on days 24-43 of postinfection.