Clinical, parasitologic, and immunologic evolution in dogs experimentally infected with sand fly-derived Leishmania chagasi promastigotes

Bruno L. Travi, Elvia Yaneth Osorio, Omar A. Saldarriaga, Horacio Cadena, Carlos Javier Tabares, Alex Peniche, Shuko Lee, Peter C. Melby

Research output: Contribution to journalArticle

19 Scopus citations


Experimental infection of dogs with Leishmania infantum has yielded heterogeneous clinical, parasitologic, and immunologic results. We studied dogs infected with 105 or 104 sand fly-derived promastigotes delivered by the intradermal (ID) or intravenous (IV) routes.Total mortality over 1 year post-infection reached 23.8%.The mortality and proportion of sustained polysymptomatic dogs was highest in the IV-105 group. The early appearance of polysymptoms was associated with an increased risk of progression to death. Dissemination of the parasite to lymph nodes was faster, and the subsequent infectivity to sand flies higher, in the IV compared with ID-infected dogs. Parasite-specific IgG1 or IgG2 production was similar among the groups, but higher interferon-γ (IFN-γ) and interleukin-10 (IL-10) expression was associated with polysymptomatic dogs. On the basis of the data obtained from this study, a sample size analysis using different endpoints for future vaccine trials is described.

Original languageEnglish (US)
Pages (from-to)994-1003
Number of pages10
JournalAmerican Journal of Tropical Medicine and Hygiene
Issue number6
StatePublished - Dec 1 2009


ASJC Scopus subject areas

  • Parasitology
  • Virology
  • Infectious Diseases

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