title: Zoonotic trypanosomes in South East Asia: Attempts to control Trypanosoma lewisi using human and animal trypanocidal drugs.
abstract: Beside typical human trypanosomes responsible of sleeping sickness in Africa and Chagas disease in Latin America, there is a growing number of reported atypical human infections due to Trypanosoma evansi, a livestock parasite, or Trypanosoma lewisi, a rat parasite, especially in Asia. Drugs available for the treatment of T. brucei ssp. in humans are obviously of choice for the control of T. evansi because it is derived from T. brucei. However, concerning T. lewisi, there is an urgent need to determine the efficacy of trypanocidal drugs for the treatment in humans. In a recent study, pentamidine and fexinidazole were shown to have the best efficacy against one stock of T. lewisi in rats. In the present study suramin, pentamidine, eflornitine, nifurtimox, benznidazole and fexinidazole, were evaluated at low and high doses, in single day administration to normal rats experimentally infected with a stock of T. lewisi recently isolated in Thailand. Because none of these treatments was efficient, a trial was made with the most promising trypanocide identified in a previous study, fexinidazole 100mg/kg, in 5 daily administrations. Results observed were unclear. To confirm the efficacy of fexinidazole, a mixed infection protocol was set up in cyclophosphamide immunosuppressed rats. Animals were infected successively by T. lewisi and T. evansi, and received 10 daily PO administrations of 200mg/kg fexinidazole. Drastic effects were observed against T. evansi which was cleared from the rat's blood within 24 to 48h; however, the treatment did not affect T. lewisi which remained in high number in the blood until the end of the experiment. This mixed infection/treatment protocol clearly demonstrated the efficacy of fexinidazole against T. evansi and its inefficacy against T. lewisi. Since animal trypanocides were also recently shown to be inefficient, other protocols as well as other T. lewisi stocks should be investigated in further studies.
authors.affiliation: UMR InterTryp, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), Montpellier F-34000, France; Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Marc
authors.initials: M
authors.lastname: Desquesnes
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Sarawut
authors.initials: S
authors.lastname: Yangtara
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Pawinee
authors.initials: P
authors.lastname: Kunphukhieo
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand. Electronic address: fvetspj@ku.ac.th.
authors.forename: Sathaporn
authors.initials: S
authors.lastname: Jittapalapong
authors.affiliation: UMR Intertryp, Institut de Recherches pour le Développement (IRD), Campus International de Baillarguet, F-34398 Montpellier, France; Department of Parasitology, Faculty of Veterinary Medicine, Kasetsart University, Chatuchak, Bangkok 10900, Thailand.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Herder
mesh_terms: D000818:Animals; D006801:Humans; D021261:Parasitic Sensitivity Tests; D051381:Rats; D012376:Rodent Diseases / Q000469:parasitology; D014344:Trypanocidal Agents / Q000494:pharmacology / Q000627:therapeutic use; D014345:Trypanosoma / Q000187:drug effects / Q000235:genetics; D014350:Trypanosoma lewisi / Q000187:drug effects; D014352:Trypanosomiasis / Q000453:epidemiology* / Q000469:parasitology* / Q000517:prevention & control / Q000635:transmission; D015047:Zoonoses / Q000453:epidemiology* / Q000469:parasitology* / Q000517:prevention & control / Q000635:transmission
chemical_list: D014344:Trypanocidal Agents
keywords: Benznidazole; Efficacy; Eflornitine; Fexinidazole; Nifurtimox; Pentamidine; Rats; Suramin; Trypanocidals; Trypanosoma evansi; Trypanosoma lewisi