i 4 THOMPSON YATES AND JOHNSTON LABORATORIES REPORT 
The following table indicates the results of examinations of cover-slip preparations 
of finger blood taken from four hundred and sixty-five natives at Leopoldville. The 
results of similar examinations, made in the region lying between Stanley Pool and 
the sea, are appended in order to present a concise idea of the prevalence of human 
trypanosomiasis in the Congo : — 
Class of Native 
Number examined 
Number with 
Trypanosomes in 
Finger Blood 
Number of Cases 
somes previously 
diagnosed as sleep- 
ing sickness 
Healthy labourers, prisoners, women, 
and children, all resident for varying 
periods in or near Leopoldville, but 
many of whom are natives of distant 
parts of the Free State 

255 
6 
O 
State Doctor at Leopoldville and 
chosen for examination because of 
their miserable appearance ... 
53 
3 
2 
Patients admitted by State Doctor to 
native hospital 
i57 
+5 
3+ 
Total for Leopoldville 
465 
5 + 
36 
Total of previous examinations at Boma, 
Matadi, and in the Cataract Region . 
707 
49 
2 1 
Totals ... 
1,172 
103 
57 
In the British Colony of the Gambia only six cases of human trypanosomiasis were 
found among 1,043 natives. 1 These cases presented no definite symptoms of illness 
and nothing abnormal was detected, with the possible exception of an occasional 
rise in temperature and increase of pulse frequency. 
In the Congo we have also seen examples ot the mild Gambian type, but the 
majority of our cases have shown marked symptoms of illness. From a close study 
of these cases it becomes evident that there is no well-defined line of demarcation 
between these two forms of the disease, though for descriptive purposes we propose 
to consider them under three main headings, A, B, and C : — 
Type A. Cases with no definite symptoms of illness. 
,, B. Cases with few symptoms. 
,, C. Fatal cases showing well-marked symptoms, the most notable being 
fever, lassitude, weakness, and wasting. 
1. Dutton, J. E., Todd, J. L., First Report of the Trypanosomiasis Expedition to Settegamiia (1902), Liverpool School of 
Tropical Medicine, Memoir XI. 
