title: Chemotherapeutic effects on larval stages of Schistosoma mansoni during infection and re-infection of mice.
abstract: The sensitivity of the larval stages of Schistosoma mansoni to chemotherapy with praziquantel and oxamniquine was tested in mice during primary and secondary infections and after different intervals from cercarial exposure. Worm recovery by perfusion of the porto-mesenteric system, followed by counting and a morphometric study of the parasite, allowed the conclusion that the relative resistance of the larval stages of S. mansoni to schistosomicide drugs, demonstrated in primary infections, also persists when the host is already infected. This indicates that a therapeutic failure may result when an infected host is treated some time after being re-infected, because of the presence of migrating, drug-resistant, immature forms of the parasite.
authors.affiliation: Laboratório de Patologia Experimental, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, Salvador, BA, Brazil.
authors.forename: Luciana M
authors.initials: LM
authors.lastname: Silva
authors.forename: Rejane M C
authors.initials: RM
authors.lastname: Menezes
authors.forename: Sheilla Andrade
authors.initials: SA
authors.lastname: de Oliveira
authors.forename: Zilton A
authors.initials: ZA
authors.lastname: Andrade
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000494:pharmacology*; D005260:Female; D007814:Larva / Q000187:drug effects; D008297:Male; D051379:Mice; D010073:Oxamniquine / Q000494:pharmacology*; D021261:Parasitic Sensitivity Tests; D011223:Praziquantel / Q000494:pharmacology*; D012550:Schistosoma mansoni / Q000187:drug effects*; D012556:Schistosomicides / Q000494:pharmacology*
chemical_list: D000871:Anthelmintics; D012556:Schistosomicides; D010073:Oxamniquine; D011223:Praziquantel