1. The object of the paper is to record some
clinical observations made during the study
of 94 consecutive cases of Rhodesian Sleeping Sickness.
2. The main factor in the epidemic spread was
man-fly-man transmission. The occurrence of
human cases with no history of contact and
the high T.bracei infection rate among the
local fauna are recorded, as the possibility
of there being some reservoir cannot be excluded.
3. The incubation period is probably between
4. The average duration of the illness is five
5. There was an acute febrile onset in 24/£ of
cases. Variations in the subsequent course
are found and it is considered that these are
due to the existence of strains of trypanosoines of different virulence.
6. The central nervous system may be involved at
a very early stage. This results in grave pathological changes, but the virulence of
the infection is such that symptoms arising
from its effect on the heart and other viscera predominate over those due to central
nervous system involvement until the last few
weeks of the illness. Cardiac symptoms are
important and the essential lesion is a toxic
7. The axillary group of glands are those most
8. It is in cases which have relapsed after treatment that mental symptoms are most pronounced.
In relapse a new strain of trynanosames has
been created, of lowered virulence but resistant to the action of drugs.
9. 'Bayer 205' has a strong and immediate effect
oh infections of the peripheral blood but its
action is not always permanent and it cannot
penetrate into the deeper tissues. Tryparsamide is slower in action but it maintains a
sterilization made by 'Bayer' and it can exert a beneficial action on the central nervous system.
10. Treatment by * Bayer* should he followed immediately by Tryparasmide • A routine treatment
by this method gives satisfactory results if
treatment is started early in the course of
the illness, hut even the most intensive and
prolonged doses of the two drugs in combination cannot he relied upon to effect a cure
if the disease is well established.