Published online by Cambridge University Press: 15 May 2009
The origin and object of the following paper can be explained in a few words. In April, 1904, the writer published a series of 280 blood examinations (to which were added about 150 more) of natives of southern Angola (Portuguese West Africa) without recording a single instance of the presence either of trypanosomes or of spirochaetes in the circulation. Quite recently in the course of an investigation of the endemic malaria of the same district, 513 examinations made among the same people and with the same technique revealed 3 individuals harbouring trypanosomes and 4 showing spirochaetes in their blood. These observations, together with the fact that a year or so ago the natives reported no cases of Tick Fever, while recently statements are made by them that the Tick Fever of the upper Zambezi has reached Angola, and also the fact that Sleeping Sickness is reported to be advancing southward through the province, have led me strongly to suspect that these diseases have lately begun to spread markedly in my part of the colony, and that one or both of them may not inconceivably assume in the near future epidemic proportions.