Echinococcus multilocularis survived, strobilated and matured sexually in the small intestine of 6-week-old male golden hamsters that were either non-treated or treated with prednisolone tertiary-butylacetate (PTBA), following oral administration of 20000 protoscoleces. Non-treated hamsters harboured the adult worms for up to 25 days post-infection (p.i.). Hamsters treated with PTBA from the day of infection (day 0 p.i.) harboured more adults than the non-treated, and their survival periods were extended. Moreover, a remarkable improvement in worm recovery, development and survival periods was observed in hamsters additionally treated with PTBA on days — 14 and — 12 p.i., and the worm development including proglottisation, sexual maturation and egg formation was comparable with that in dogs. With the present results it is suggested that Echinococcus/rodent systems represented by the E. multilocularis/golden hamsters may rejuvenate the current stagnant research on host-parasite interactions of the definitive host-stage and egg-stage of Echinococcus.

Two expeditions were carried out during September 1997 and March 1999 to confirm the current existence of Mesocricetus auratus in northern Syria. Six females and seven males were caught at different sites near Aleppo. One female was pregnant and gave birth to six pups. Altogether, 30 burrows were mapped and the structures of 23 golden hamster burrows investigated. None of the inhabited burrows contained more than one adult. Burrow depths ranged from 36 to 106 cm (mean 65 cm). Their structure was simple, consisting of a single vertical entrance (gravity pipe) that proceeded to a nesting chamber and at least one additional food chamber. The mean length of the entire gallery system measured 200 cm and could extend up to 900 cm. Most burrows were found on agricultural fields preferentially on leguminous cultures. The distribution of golden hamsters is discussed in association with historical data, soil types, geography, climate and human activities. All 19 golden hamsters were transferred to Germany and, together with three wild individuals supplied by the University of Aleppo, form a new breeding stock.