2 59 
VII. DIAGNOSIS 
An absolute diagnosis, of course, depends upon the demonstration 
of the parasite. The charts of the Kasongo cattle show that every 
means may frequently fail to show the parasites in infected animals. 
Of all the methods gland puncture was the most successful. In 
thirty consecutive examinations, at which parasites were detected 
either in the gland juice or in the blood, gland puncture was successful 
twenty-nine times, the examination of cover-slip preparations of blood 
thirteen times ; on one occasion trypanosomes were present in the 
blood and were not seen in the gland juice. T he same precautions 
must be taken in puncturing the glands of cattle as in those of men. 3 
The records of the animal inoculations (particularly at Kasongo, 
page 243) show that the animals we employed frequently remained 
uninfected after the inoculation of large quantities of blood containing 
living parasites. As a diagnostic test the sub-inoculation of laboratory 
animals was therefore often less sensitive than the examination of 
cover-slip preparations of blood. 
If we except the cattle at Romee (seven laboratory animals, all infected), the 
bovine trypanosomes (i.e. , first passages) were remarkable for their slight virulence 
in direct inoculation. Of twelve rats, four guinea pigs, two rabbits, two monkeys 
and four dogs inoculated at various stations, only one rat ever became infected. 
It is noteworthy that at present sub-inoculations into ordinary laboratory animals 
°f the strain derived from this rat are always successful. The virulence of this 
trypanosome in direct inoculations therefore seems to have increased for the 
animals employed. The original strains of trypanosomes obtained from the 
antelope and from Commandant Sillye’s stallion at Kasongo were much more 
•irulent in the first passages. 
No idea was formed of the absolute efficiency of gland palpation 
as a diagnostic test. In the animals found to be infected the 
superficial lymphatic glands were usually considerably enlarged ; some 
" ^em, not advanced cases, however, bad no evident glandular 
en largenient. Many of the animals examined once, and not found to be 
infected, had glands as large as, or larger than, those seen in the 
'nfected animals (this was especially so at Kasongo). 
. In the Gambia 6 it was noted that a heightened temperature 
urnished a valuable indication of possible trypanosome infection in 
^■ Charts I, II, HI, IV and V fully confirm this observation; 
° Ul a h, g h temperature observed once in an animal just thrown after 
a stru ggle in the sun has but little value. In such circumstances 
Stares of from ioic°F. to I03°F„ or more, were noted in 
Q 
