Report on the etiology and prevention of yellow fever / by George M. Sternberg.

  • Sternberg, George Miller, 1838-1915.
Date:
24 cm
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Licence: Public Domain Mark

Credit: Report on the etiology and prevention of yellow fever / by George M. Sternberg. Source: Wellcome Collection.

Provider: This material has been provided by London School of Hygiene & Tropical Medicine Library & Archives Service. The original may be consulted at London School of Hygiene & Tropical Medicine Library & Archives Service.

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    itis necessary to establish a well-drawn distinction as to the blood; ILe blood of tlie general circulation sl.ows itself nuicb less charged with the microbes than the blood of the capillaries. Thus, if I could admit any preference on the part of the microbe xauthogenicus, I would say that it pleases itself better in the blood of the capillaries, in the blood which bathes immediately the anatomical elements. The occasion seems to us a favorable one in order to call attention to some indis- pensable precautions when the microbes of yellow fever are to be sought in organic tolids and liquids. While it is extremely easy to perceive the presence of the microbes of vellow fever in the urine and bile, for example, by placing a drop of these liquids upon a glass slide, covering it with a thin glass cover, and examining it with a power of 450 to 740 or 780 diameters, this proceeding can not be employed when the blood is to be examined. If we proceed in this manner the globules will hide nearly all of the microbes, and the observer will wrongfully conclude that they are very rare in this oro-anic liquid. Not only does the form of the microbe offer a certain resemblance to that^of the red corpuscles, but these latter in adhering together envelope the mi- crobiau cells, and on the other hand cast upon the cells a jet of light which makes them disappear from the field of the microscope. But if we dilute a little drop of blood in a pure solution of sulphate of soda and place it under thp objective, the microbes become visible and will appear in consid- erable quantity. It is likewise necessary to make a preparation previously for the examination of the cerebral mass and of the muscles. They should be triturated in a sterilized mortar and mixed afterward with distilled water entirely deprived of organisms, filtered through fine linen which has been passed rapidly through the flame of an alcohol lamp, and afterward a drop of the filtered liquid should be placed upon a glass slide. If we withdraw a little piece of brain or of muscular fiber, even triturated, we will not perceive anything abnormal under the microscope, unless it be the anatomical elements more or less deformed by trituration. It is not the same for the liver. It suffices to withdraw a bit of this organ and to crush it between two glass slides. Upon observing it under the microscope we perceive at once a multitude of microbes. This is because in the muscles the microbes are lodged between the fibrillse and in the substance which surrounds them; and in the braiu they are found in the interior of the nerve cells, which must first be destroyed by trituration in order that their parasitic hosts may become visible. Having made extended researches in Havana in 1879 and during the past year in Brazil and in Mexico, I am able to assert most positively that no such microorgan- ism as Dr. Froire has described is to be found in the blood and tissues of yellow-fever patients. I have examined blood from numerous cases drawn from the finger during life, both in the fresh condition, in preparations stained by various aniline colors, and by culture methods, and I have studied with great care a large number of thin sections of the liver and kidney, stained by the most approved methods, from a con- siderable number of typical cases of yellow fever, without having encountered the cryptococcus xauthogenicus. As Dr. Freiro asserts that his microbe is especially abundant in the capillary ves- sels, it should be easily demonstrated in thin sections of the various organs, made aecundem artem. As a matter of fact, my researches show that, as a rule, no microorganism demon- strable by known methods of staining is to be found in such sections. But here I must state that in certain cases microorganisms have been found. The one to which tlie most interest attaches is that described by Babes. This was discovered in 1864, iu material sent to Paris from the laboratory of Dr. Lacerda, in Rio de Janeiro. At the time of my visit to Brazil my friend Dr. Aranjo Goes gave me material from nine cases, which had been preserved in Dr. Lacorda's laboratory since the epidemic of 1884, and after my return to Baltimore I examined sections stained by Gram's