The diagnostics and treatment of tropical diseases

by E. R. Stitt

Consequently, while in possession of full energy and zeal one should cultivate thorough and modern methods of study of his cases and make these matters of routine, to use in the listless period to follow.

We do not usually fully appreciate the assistance the history of the present illness as well as personal and family history of a patient gives us, although it is generally recognized as the first line of approach in diagnosis. In the tropics, when dealing with natives, we have the difficulty of language to contend with as well as with native superstition and popular ideas as to nature and causation of disease. When employing a native interpreter it is always well to keep in mind the fact that such assistants will rarely admit of ignorance of the language of the medical man and, furthermore, they try to twist the answers of the patients to make them agree with what they may think is in accordance with the desire of the examiner. Again in carrying out the physical examination it is difficult to be certain that the findings as to location or degree of pain, sensations, or time of appearance of lesions, as well as data as to pulmonary, renal and alimentary tract disorders, are correct.

For these reasons it would seem advisable to reverse the ordinary methods of diagnosis when employed in the tropics. Instead of making a tentative diagnosis following the physical examination, and then confirming or adding to evidence with laboratory data, it is better to first secure the findings as to blood, faeces, urine, sputum, etc., and then check up such indications as to the diagnosis by a final and thorough physical examination.

This method of procedure has been criticised by some of my friends and in fact is a source of criticism on my part when, as a laboratory worker, I have been asked by a purely clinical colleague to make a routine laboratory examination of one of his patients without any previous study of the case on his part. Every laboratory man recognizes the assistance a tentative diagnosis on the part of the clinician gives him in that it suggests the examinations which should be gone into with particular care.

The present trend, even in temperate climate practice and always with the tropical internist, is to have familiarity with laboratory technique and interpretation as well as with the methods of physical diagnosis; consequently the tropical practitioner makes no dividing line between the diagnostic information obtained in the laboratory and that gotten at the bedside.

It is not difficult to train a native helper to make and stain good blood smears as well as to examine such preparations, and the same holds for the urine and faeces preparations. The skill in making preparations, the familiarity with pathological findings and the patience in studying a preparation on the part of these assistants is at times a matter of surprise. Thus in a few minutes the physician can check up these findings or the lack of findings and have them at hand to assist him in his study of his case.

Laboratory Examination.—In the laboratory the routine examination should embrace, first, a study of a stained blood smear. It is essential that the smear be well made and the Romanowsky stain used a good one.

While more difficult to make than a smear on a slide the cover-glass smear method of Ehrlich has the advantage that the white cells are more evenly distributed and consequently the differential count more reliable. Furthermore, after a little practice, one can approximate the white count of a patient by examining the stained smear with a low power objective (16 mm). In my experience I get a better general impression of a large mononuclear increase with the low power than I do with the oil-immersion. As a matter of fact one can make his differential count with a low power objective after some practice. Next, using a high dry or immersion objective, we search for malarial parasites. It must be remembered that even when there is nothing diagnostic in a stained blood smear there is much information to be obtained in the way of diagnostic exclusion. Furthermore, while looking over the preparation some diagnosis may suggest itself and there is nothing more important in diagnosis than to have possibilities of diagnosis in mind. It is often stated in connection with the diagnosis of liver abscess that one should always suspect liver abscess in a tropical patient and this will hold for other diseases and thus the careful examination of a blood smear may be suggestive if not diagnostic.

Next the faeces should be examined both in an ordinary preparation and in one mounted in Gram’s iodine solution.