H. L. Duke 359 
to about 6000, of whom very many came from Sesse and the lake-shore region. 
A very large number died en route. 
0 
( b ) Acute type of the disease in the early days of the epidemic. 
A perusal of the early Uganda reports (Greig, 1905) reveals the rapid 
course of the disease in many of the cases examined during the early days of 
the epidemic, although some patients, such as Kamsasabba, lived for several 
years. It is to be noticed that at the time of admission most of these acute 
cases had trypanosomes in their cerebrospinal fluid, though the parasites 
were not so frequently seen in the blood. Post mortem, the body was often 
not emaciated. The patient’s account of his symptoms usually included 
headache and general limb pains. In cases 69 GT, a male of 16 years, and 
69 FV, a male of 12 years, the disease lasted about six weeks and 3J months 
respectively. Case ZM 69 male of 35 years, is described on admission as 
“appears to be in early stage” on 6. vii. 1904, but he died on 22. viii. 1904. 
His body was not emaciated. He said he had been ill for three months before 
admission, and this makes the total course about 4J months. 
Enquiries among old Basesse who lived through the epidemic on the 
Islands all point to the disease having been very acute in the early days, the 
limits given being 14 days to 6 months from the time it was first noticed in 
the sick person. Those lived longest who suffered at the same time from other 
diseases such as chronic gonorrhoea. This last statement is interesting, as it 
was volunteered spontaneously and not in response to a leading question. 
The virulent nature of the disease in some of these early Uganda cases 
is thus different from what is ordinarily expected with T. gamhiense in African 
natives. 
(c) Direct-transmission hypothesis as an explanation of the 
virulence of the epidemic. 
In a paper published in 1919 (Duke, 1919 b) a hypothesis was advanced 
to account for the extraordinary wave of virulent trypanosomiasis which 
constituted the Uganda epidemic. The contention was that, given a certain 
degree of contact between G. palpalis and man, direct as opposed to cyclical 
transmission might lead to the development of a strain of enhanced virulence 
which would persist until it automatically died out with the removal, by 
death or other causes, of the degree of contact necessary for its propagation. 
Such a strain when cyclically transmitted, might present a very different 
degree of virulence. Attention was directed to the drop in the annual death-rate 
per thousand in the fly area, a drop which had commenced before any de¬ 
population measures were started. To-day we have a flourishing and, according 
to all accounts, an increasing population along the lake-shore of British East 
Africa, where no organised measures for depopulation or segregation were 
taken. The East African coast line suffered very severely in the epidemic. 
The Germans instituted limited deforestation measures combined with segre- 
Parasitology xm 
24 
