Trypanosoma brucei sensu lato [T. brucei s.l.] drug resistance: A roaming impediment to sleeping sickness eradication plan

Treatment of sleeping sickness and nagana is threatened by drug resistance. To guide drug use in sleeping sickness control, we set out to determine if cattle-derived drug resistant sleeping sickness causing parasites spill-over to humans as drug resistant; causing sleeping sickness treatment failure. We screened cattle (n= 2,750) and sleeping sickness patients (n=147) from south-eastern Uganda for drug resistant sleeping sickness [T. b. rhodesiense]] and nagana causing parasites [ T. brucei s.l. ] and hence determined their prevalence in either populations using sound statistical means. One in three cattle [949/2,750] was positive for T. brucei s.l. and about 90 of every 100 of these parasites had changes in their genes induced by drug use. More than half of the sleeping sickness patients carried T. b. rhodesiense with changes in their genes induced by drug use and their occurrence was spatially related to those in cattle. Drugs are still effective in both nagana and sleeping sickness control in south-eastern Uganda since the genetic changes in nagana and sleeping sickness causing parasites detected in this study do not reduce drug effectiveness against these parasites. It is very likely that genetic changes in T. b. rhodesiense occur in cattle and are then transmitted to humans.