Improved diagnosis of trypanosome infections and drug resistant T.congolense in livestock

The aim of this thesis was to provide a picture of the trypanosomosis and drug resistance prevalence in Eastern Province of Zambia, to understand the underlying factors of drug resistance (drug use habits), to improve the diagnosis of trypanosomosis in livestock and finally, to improve the diagnosis of isometamidium resistance in T.congolense. After an introductory part where available trypanosomosis and trypanocide resistance diagnostic methods are described and discussed, the body of the thesis is divided in two main sections. In the first section are presented the results of a cross-sectional and a longitudinal epidemiological survey describing the geographical distribution of trypanosomosis cases, of resistant isolates and of cattle treated with isometamidium chloride. The results of the monitoring of unsupervised treatments of cattle with isometamidium by farmers and veterinary assistants with the Isometamidium-ELISA technique are also presented. The second section describes the development of two new diagnostic methods, the first one allowing the diagnosis of trypanosome infections with high sensitivity and specificity through semi-nested polymerase chain reaction and restriction fragment length polymorphism. This is the first report of a pan-trypanosome PCR test (a single PCR test for the diagnosis of all important pathogenic trypanosomes of cattle). The second new method that was developed allows the diagnosis of isometamidium resistant T.congolense strains by PCR-RFLP. This is the first report of a PCR based diagnostic test of trypanocide resistance in T. congolense.<p>Doctorat en sciences, Spécialisation biologie moléculaire