Experiments to investigate the infectivity of Glossina palpalis fed on sleeping sickness patients under treatment

Abstract

It is well known that there are cases of Sleeping Sickness in man which, under treatment, may enjoy long periods of apparent good health. In these cases the individual is often able to live an active life, and insists on being at liberty to go about as he pleases. In Uganda care is taken to prevent such cases entering the fly-area; but the difficulty in maintaining a supervision strict enough to check occasional visits to these areas is obviously great, and in other countries may be insuperable, so that the question as to how drug treatment can influence the infectivity of these patients to the fly may be considered to be of importance. Other points arise from the consideration of this question, viz.:—Can one or more doses of a trypanocidal drug render a Sleeping Sickness patient non-infective to Glossina palpalis ? Does prolonged treatment during any stage of the disease render cases of Sleeping Sickness innocuous to the fly ? If it be proved that the treatment of Sleeping Sickness patients by certain drugs does not prevent them infecting Glossina palpalis , then what percentage of cases give a positive result ? and what percentage of flies are infected from these cases, as compared with the number of flies infected from untreated cases ?