Advantage of the PCR technique in assessing the epidemiology of bovine trypanosomosis: example of the agropastoral development area of Yalé, Burkina Faso

Abstract

The PCR (polymerase chain reaction) technique was used to identify trypanosomes both in tsetse and infected cattle in the agropastoral development area of Yalé in southern Burkina Faso. Out of 84 parasitologically positive midguts of Glossina tachinoides, 50 (Trypanosoma congolense savannah and riverine forest types, T. simiae and T. vivax) were identified by PCR. Using PCR on bovine blood samples, it was found that T. congolense savannah type and T. vivax were predominant, while the riverine forest type of T. congolense could not be detected. Some aparasitaemic but clinically suspected animals reacted positively when specific primers for the savannah type of T. congolense were used. The results confirmed the high potential of the PCR technique in detecting cryptic and/or mixed infections in the different hosts. Added to previous studies describing comparable approaches, the present results show that the tools using molecular biology can provide valuable information on the complex relationships between the savannah or riverine forest types of T. congolense and their vectors, and also their vertebrate hosts. This probably enables the molecular markers to be considered as pathogenicity markers. Their diagnostic capability and their helpful part in approaching the parasite/ host relationship for better control in the field are discussed.