Trypanosoma evansi: A clinical, parasitological and immunological evaluation of trypanosomosis using a chronic rabbit model

Abstract

We evaluated the clinical, parasitological and immunological effects of a Venezuelan strain of Trypanosoma evansi (T. evansi) throughout in experimentally inoculated rabbits over the course of infection and compared them with the same aspect in healthy animals. Body temperature was recorded in degrees Celsius, animal weight in kilograms, serum proteins in g/dl using a refractometer, haematocrit percentage by capillary  centrifugation and the anti-T. evansi IgG titer by indirect ELISA immunoassay, from both infected animals and controls for 95 days. Infected animals showed a higher body temperature, total serum protein and anti- T. evansi antibody titer, and a lower haematocrit and weight gain than controls. These differences were related to the presence of the parasites in the blood as detected micro-haematocrit centrifugation technique (MHCT) and direct microscopic examination (DME). This study confirms the usefulness of rabbits as a model for the study of trypanosomosis; the clinical features of the disease can be observed and the three characteristic stages, prepatent period, acute and chronic phase clearly defined over the course of the infection.

Key words: IgG, Temperature, Total serum protein, Trypanosomosis, Weight.