TRYPANOSOME OCCURRING IN THE BLOOD OF MAN 463 
Veterinary Surgeon J. H. Steel, A.V.D.,' in 1885, described very fully a disease 
occurring among the transport mules in British Burma, in which he found 
organisms in the blood of these animals, shown later to be identical with those found 
by Evans in India. The symptoms were very similar to those described by Evans. 
Steel shewed that the fever was of a relapsing character. In inoculation experiments 
under the skin, the incubation period was five days ; the first acute febrile attack lasted 
three days with an interval of five days before the next, when the temperature would 
remain about normal, with, perhaps, slight evening rises. In these apyrexial periods 
the symptoms abated somewhat, and the blood was free from detectable parasites. 
Besides the anaemia, swellings, petechiae and ulcers, etc., associated with general 
wasting, he pointed out the enlargement of the spleen as a constant feature in the 
disease, and some enlargement of the lymphatic glands. Ulceration of the stomach 
was found after death with a general oedematous and congested condition of the 
organs and areolar tissues. 
Surgeon-Major Bruce, 2 in 1896, has described the symptoms of Nagana in various 
animals. 
In the horse, the first noticeable features are that his coat stares, and there is a 
watery discharge from the eyes and the nose ; shortly afterwards there appears a 
slight swelling under the belly or a puffiness of the sheath may be noticed, and the 
animal falls off in condition, hind extremities tend to become swollen, at times more 
marked than at others, the animal becomes more emaciated ; eyes and gums are pale, 
and probably a slight milkiness of the cornea is observable ; no symptoms of 
pain ; up to the last a fairly good appetite ; animal falls down, unable to rise 
and dies of exhaustion. Other points recorded in his notes on the cases are 
the anaemia, red cells decreasing from 5,500,000 to 2,500,000; petechial spots on the 
mucous membranes, swollen glands. He describes the temperature as very irregular ; 
in a temperature chart given of a horse which had been taken into the ' Fly country ' 
and there contracted the disease, it is interesting to note the close relation between 
the presence and number of parasites in the blood to the rises of temperature. 
The disease started on October 4, temperature reaching 104*8 next day ; with 
numerous parasites in the blood, on October 21 and 22 temperature was normal 
(varied from 90 0 to 102°) ; on these days the blood was examined, and no 
parasites found. On the evening of October 23 temperature arose to 107 0 , and 
numerous parasites were present in the blood. Next day temperature dropped to 
100 0 ; no parasites were found. On subsequent days the parasites increased from 
four hundred to five thousand on October 28 ; the evening previous there had been 
a rise of temperature to 106 0 . After the rise the parasites diminished slightly, with, 
at the same time, a slight diminution of temperature, until October 31, when 
1. Report of Vet. Surgeon J. H. Steel, A.V.D. , on his investigations into an obscure and fatal disease among transport 
mules in British Burma. 1885. 
2. Tsetse-fly disease or Nagana in Zululand, Durban, 1894. Further report on tsetse-fly disease in Zululand, London, 1897 
