TRYPANOSOMIASIS EXPEDITION TO THE CONGO 35 
We have not yet met with an epidemic of sleeping sickness in the Congo, although 
at least one has been recorded. 1 From the answers to inquiries, which we have received 
from state doctors and officials in different parts of the country, we do not think that 
the disease exists in any part of the Congo in a much more severe form than at 
Leopoldville, and certainly there is no epidemic comparable to that in Uganda. 
It will be noted that the Congo type of case, as we have described it, bears a close 
resemblance to some of the cases described by Bruce and Nabarro on the Victoria 
Nyanza, at a time many months alter the epidemic wave had passed eastward, and at 
a place Entebbe, situated at the extreme tail of the epidemic area. Moreover, one 
of us is able to recognize a similarity between many of the cases seen here, particularly 
those in which emaciation, lengthened period of illness, and absence of sleep, are the 
main features, and many of the cases seen by him on Buvuma Island, also situated in 
Victoria Nyanza, and towards the tail of the epidemic area. 2 
The Course of the Disease 
Duration. It has been impossible to decide for how long a period a native may 
be infected with trypanosomes and still show no definite signs of disease. One man 
already mentioned, is known to have been infected for over a year and is still perfectly 
well. It would appear from one or two early cases which have been observed that the 
transition from this 'latent' stage to one in which symptoms are noticed may be very 
gradual. We have only observed eight fatal cases of Congo sickness in which the 
necropsies showed no obvious secondary infection. The duration of the disease, dating 
from the recognition, either by the friends of the patient or by ourselves, of obvious 
signs of ill-health, has been from two to four months. 
Recovery. In our experience no native who has shown definite and constant signs 
of ill-health has recovered. 
Since we have been in Leopoldville we have frequently seen a case of trypano- 
somiasis in a European, reported by Dr. Broden 5 and Sir Patrick Manson. 4 
Mrs. M., a missionary stationed at Leopoldville, states that her illness commenced on October I, 
1900, with a fever which lasted for three months and was not amenable to quinine. Since that time 
she had not been free from constantly recurring fever, except for two periods, in 1901 and 1902, each of 
three months duration, up to March 19, 1903. Since the last date she has been absolutely free from 
fever or other signs of trypanosoma infection up to the present (April, 1904). She is apparently in 
perfect health and has increased in weight. The trypanosomes were found by Dr. Brodkn on February 
~, 1903, during an attack of fever which lasted for a few days. During the last year Dr. Brodln has 
seen no parasites in the blood of this case. 
Death. We do not think that we have sufficient evidence to state that death is 
produced by the trypanosomes alone. 
1. Bcrgh St. Marie in the Portuguese Comm'ssion's Report. 
2. Christy, Reports of the Sleeping Sickness Commission, Royal Society, No. III. 
3. Broden, Ibid. 
4. Manson, Ibid. 
