In Brazil there is a disease caused by a flagellate, Schizotrypanum cruzi, which resembles a trypanosome and is transmitted by a bug, Lamus megistus. The disease runs an acute course with a high fever and great mortality in infants showing chiefly manifestations of involvement of brain or thyroid gland. In adults it runs a chronic course showing neurological manifestations or signs of myxoedema or even of Addison’s disease.
Synonyms.—Sleeping sickness; Negro lethargy. French: Maladie du sommeil. German: Schlafkrankheit. For the Brazilian trypanosomiasis, Schizotrypanosomiasis; Chagas’ disease.
History and Geographical Distribution
History.—In describing sleeping sickness, in 1803, Winterbottom brought out the importance of enlargements of the posterior cervical glands (Winterbottom’s sign).
In 1880 Evans had found a trypanosome in the blood of horses affected with surra and several years afterward Bruce discovered that nagana, a fatal disease of cattle, was due to a trypanosome, T. brucei. In 1890 Nepveu found a trypanosome in the blood of a man in Algeria but owing to vagueness of description the discovery did not attract attention.
Fig. 25.—Geographical distribution of African trypanosomiasis.
In 1901, Forde found a parasite in the blood of a patient in the River Gambia Colony who had a fever and in 1902 Dutton recognized the parasite as a trypanosome and gave it the name T. gambiense. In 1902, Castellani, finding a trypanosome in the cerebro-spinal fluid of a patient with sleeping sickness, brought about the establishment of the connection between the trypanosome in the blood (trypanosome fever) and the trypanosome in the cerebro-spinal fluid (sleeping sickness). In 1903, Bruce and Nabarro reported that this disease was spread by a tsetse fly, Glossina palpalis.
In 1910 Stephens and Fantham brought forward the existence of a more virulent trypanosome, T. rhodesiense.