Abstract:
Sleeping sickness or Human African trypanosomosis (HAT) is a protozoal disease that is
transmitted by tsetse fly vectors in Africa. Sleeping sickness due to T. b. gambiense is a major
public health problem in countries in central and western Africa including Angola, Uganda,
Democratic Republic of Congo (DRC) and Sudan. High rates of relapses (>20%) following
melarsoprol treatment have been reported in many treatment centres including the MSF-F
treatment centre at Ibba in south Sudan. The treatment failures could be due to individual
(patients) variation in the drug pharmacokinetics, the patient’s immune responses, or drug
resistant parasites.
There is a growing interest in the elucidation of the reason(s) for relapses after melarsoprol
treatment. Since the drug levels in blood or CSF do not differ between relapse and
successfully treated patients, drug resistance has been suggested as a likely cause for
melarsoprol treatment failures. There are no recently isolated parasites from high-relapse
areas and hence detailed studies have been hindered. The objective of this PhD study was to
isolate and characterize (phenotypically and genotypically) T. b. gambiense from HAT
patients in the MSF-F treatment centre at Ibba.
