Report on the public health / Southern Rhodesia.

  • Southern Rhodesia. Department of Health.
Date:
[1935]
Catalogue details

Licence: Public Domain Mark

Credit: Report on the public health / Southern Rhodesia. Source: Wellcome Collection.

    31/42 (page 27)
    Schick Tests : 455 Schick Tests were performed during1 the year using the material supplied by the South African Institute for Medical Research, each test con¬ sisting of a test and a control injection. These tests were carried out on children of school age and the following results were obtained: — Positive, 236; Negative, 219. In the course of the year an attempt was made by means of the Schick Test to assess the immunising value of the diphtheria anatoxine in common use throughout the country. The results obtained are being investigated by the Serology Department of the South African Institute for Medical Research. Clinical Pathology : Haematology.—A steady increase has taken place in routine hematolog¬ ical investigations during the last two years due to a keener appreciation of the significance of the anemic states in the causation of conditions of vague ill-health, particularly amongst Europeans. Thus 745 blood counts were carried out during the year, as follows: — Europeans : Complete counts, 72; red cell counts, 200; total white cell counts and differential counts, 173; differential counts on smear preparations, 187. Natives: Complete counts, 9; red cell counts, 29; total white cell and differential counts, 9; differential counts on smear preparations, 66. Attention has already been drawn to the incidence of anaemic states amongst Europeans resident in Southern Rhodesia and the wmrk of the cur¬ rent year confirms the earlier findings. The subject has been discussed in general terms in a recent publication—vide list of publications at the end of this Report. Reticulocyte Counts.—A special investigation of the reticulocytes in experimental trypanosomiasis was carried out during the year. A strain of T. brucei recovered from a dog was inoculated intraperitoneally into guinea pigs, white rats and rabbits and the reticulocyte response studied in the two latter animals. In the white rat with its highly plastic marrow a vigorous reticulocytosis occurred approximately seven days after an intra- peritoneal injection of infected blood. Coincident with reticulocytosis, nucleated red cells appeared in the peripheral circulation. The reticulocyte response was sustained for a few days, then as the trypanosomes continued to increase the percentage fell away rapidly to sub-normal levels and the animal eventually succumbed to trypanosomiasis. In the rabbit the hsematological response to infection with T. brucei was studied in greater detail. Full blood counts were carried out at intervals and the Van den Bergh reaction ascertained with a view to determining the mechanism of the blood changes. It is not possible in the space available to give detailed accounts of the findings, but it may be stated that a reti¬ culocyte response was observed to occur about 14 days after inoculation, and as in the case of the white rat, the response was sustained for a week or ten days and was subsequently maintained at a level which fluctuated slightly above normal values. The red cells counts fell rapidly soon after the infection had established itself, to rise again in response to the reticulocytosis, but as the reticulocyte counts fell an anaemia gradually developed and persisted until death or until the infection had been cut short by an injection of trypar- samide. It is proposed to discuss the subject in greater detail in a paper to be produced at a later date. Blood Grouping and Blood Transfusions.—The blood group was ascer¬ tained on 38 occasions mainly in connection with cases for blood transfusion but also in relation to an investigation into the blood groups of the native races of the country. The demands on the Blood Transfusion Service, organised by the Laboratory, have been heavier than in previous years, the total number of transfusions arranged for numbering 22. Urine Analysis.—A full cytological and chemical analysis was carried out on 2,252 specimens of urine. The rule in this Laboratory is that all specimens of urine are subjected to a full analysis whether specifically asked for or not, with the result that on three occasions during the year unsuspected cases of diabetes mellitus were brought to light.