[Detection of Leishmania infantum in an experimentally-infected hamster using immunohistochemistry].

Abstract

Introduction: visceral leishmaniasis is considered the most severe form of this disease and can be fatal if not properly treated. In Latin America, the infection is caused by Leishmania infantum (syn. Leishmania chagasi). The unequivocal diagnosis and the selection of a suitable experimental model are required to undertake studies on this biologic agent.

Objective: to determine the advantages of immunohistochemistry in identifying Leishmania.

Methods: hamsters were inoculated with Leishmania infantum promastigotes. The body weights of every animal were monitored, and the relative weights of their spleens and livers were estimated. For identification of amastigotes, Giemsa-stained imprints and an immunohistochemistry protocol in paraffin-embedded tissues were developed.

Results: the infection was reproduced in the experimental model. The immunohistochemistry was positive in infected animal sections and non-reactive for the control group. When compared with the Giemsa staining, this methodology facilitated the identification, particularly in organs infected with few parasites.

Conclusions: immunohistochemistry is a specific tool for detection of Leishmania since it facilitates observation and eliminates any confusion in the identification of the parasite, thus improving the quality of diagnosis.