[The use of sentinel animals for the evaluation of the control of vectors of sleeping sickness: preliminary reports at a Congolese site].

A large-scale control trial against Glossina palpalis palpalis was carried out in the Congo using a new trapping technique. In the same way a test related to the experimental utilization of sentinel animals was performed, concurrently to the classical epidemiological and entomological evaluation. 564 domestic animals (pigs, sheep, goats) were examined parasitologically (wet blood films, Woo/HCT) and serologically (Testryps CATT) in six villages. When a drastic reduction of tsetse populations was achieved (i.e. zero point of apparent density) a parasitological negativation was first noted after one year and a complete serological negativation was observed after two years. If only a relative decrease in the vector's apparent densities occurred, it was related with a lower of sero-parasitological prevalence rate. The use of a serological test which was able to detect Trypanosoma congolense antibodies as the Testryp CATT, is a particularly useful technique for estimating the animal transmission level. These first results give some arguments that a parasitological and serological continuous of sentinel animals as pigs and sheep is a useful mean for evaluating the efficiency of a control campaign against sleeping sickness vectors.