[Indirect immunofluorescence in the therapeutic surveillance of trypanosomiasis (preliminary note)].

The authors have studied the evolution of fluorescent antibodies in the serum and the C. S. F. of treated Sleeping Sickness patients regularly examined when coming to Brazzaville for their periodical controls. They have observed more than 200 patients who were followed during three years. The authors demonstrated that curing patients show the following particularities: -- serum becomes negative less rapidly than C. S. F., -- delay of negativation of the serum varies according to the stage of the disease, -- the C. S. F. positive in fluorescence becomes negative in less than twelve months. On the other hand, relapsing patients show some striking differences, such as: -- C. S. F. remains always strongly fluorescent positive, -- the serology remains positive too, but can present some fluctuations. Some very particular cases such as "nuclear fluorescence only" or discrepancy between IFAT and clinico-parasitological data are then analysed. From a practical point of view, it appears that, as often as not, the evolution of fluorescent antibodies in serum and in C. S. F. allows to prognose either the cure or the relapse less than one year after treatment.