Ž . Parasitology International 49 2000 2530 Effect of praziquantel together with artemether on Schistosoma japonicum parasites of different ages in rabbits Xiao Shuhua a , You Jiqing a , Mei Jinying a , Guo Huifang a , Jiao Peiying a , Marcel Tanner b,  a Institute of Parasitic Diseases, Chinese Academy of Pre  enti  e Medicine, Shanghai 200025, China b Swiss Tropical Institute, Socinstrasse 57, B.O. Box, CH-4002, Basel, Switzerland Received 21 October 1999; received in revised form 5 November 1999; accepted 6 January 2000 Abstract The efficacy of combined treatment with praziquantel and artemether against infection with Schistosoma japonicum was tested on infected rabbits, in which 7- to 14-day-old schistosomules and 42-day-old adult schistosomes were simultaneously present. Rabbits were treated orally with praziquantel and artemether using various dosages and Ž . schedules. The therapeutic effects were evaluated by estimating the mean total worm burden TWB and female Ž . worm burden FWB and comparing them with the worm burdens in control animals treated with praziquantel or Ž . Ž artemether alone. When the rabbits received praziquantel in a single dose 50 mgkg , or daily for 2  6 days 30  60 . mgkg , the TWB was reduced by 28  66% and the FWB by 26  65%. In rabbits treated with artemether the reductions were 44  56% and 35  54%, respectively. Treatment with praziquantel in combination with artemether resulted in a significantly greater reduction of worm burden than was found for the groups treated with praziquantel or artemether alone, using the same dosages and schedules. TWB was reduced by 79  92%, and FWB by 80  93%. The results demonstrated that when rabbits infected simultaneously with schistosomules and adult schistosomes were treated with praziquantel in combination with artemether, the effects of the individual drugs could be increased significantly.  2000 Published by Elsevier Science Ireland Ltd. All rights reserved. Keywords: Schistosomiasis; Schistosoma japonicum; Praziquantel; Artemether; Combined treatment  Corresponding author. Tel.: 41-61-2848283; fax: 41-61-2717951. Ž . E-mail address: marcel.tanner@unibas.ch M. Tanner 1383-576900$ - see front matter  2000 Published by Elsevier Science Ireland Ltd. All rights reserved. Ž . PII: S 1 3 8 3 - 5 7 6 9 00 00029-5