342
noticed on high magnification. This striation, however, I was not able to make out, nor do I think it has been confirmed. There are generally four or more spirals, sometimes as many as twelve, in each organism. It is said to have cilia, and its mobility outside the body may be preserved for from 30 to 130 days: though with my specimens I was able to keep them alive for 11 days. No method is known by which it can be cultivated. As to its nature SCRAUDIN shers that the Spirocheta Ziemmani is a phase of a trypanosome, that it has a large nucleus and a micro-nucleus or blepharoplast-neither of which is present in a bacte- rial spirillum and further, that it alters its shape; and he judges from analogy that the Spirillum Obermeiris is a protozoan parasite and a phase of a trypansone. Its presence in the blood is noticeable when the temperature rises and during the time it remains elevated, but its variation in numbers does not bear any relation to the elevation of temperature though there is a progressive increase till about 20 hours before the crisis. As soon how- ever as the temperature falls no more spirilla can be found in the peripheral blood. What happens to them? METCHNIKOFF has shewn that they are gathered in the spleen where they are destroyed by the microphages and the macrophages; and this has been confirmed by the fact that monkeys into whom Relapsing Fever blood was injected and in whom the spirilla were found in the peripheral blood shewed none after the crisis if the spleen was present, but abundance when the spleen was extirpated. It would thus seem that the spleen was chiefly concerned in their destruction. GABRITCHEYSKY states that bactericidal substances appear at certain determinate periods in the blood, and that thus the spirilla are got rid of. The following experiments led him to this conclusion;—
(1.) To blood containing the spirochetæ he added blood taken from a case of Relaps- ing Fever immediately after the paroxysin, and the result was that the spirochetæ became immobile; changed form and died.
(2.) To blood containing spirochetæ he added normal serum, and the spirochetæ lived from 2 to 4 days.
(3.) Preventive inoculation with serum of a convalescent case was effective to a certain
extent.
Then also it is known that temperature influences the mobility and the life of the spirochete. They live longest, outside the body, at the room temperature. As the tem- perature is raised they become immobile and then die and contrary to what we may ex- pect, a very low temperature may suspend life, or at any rate does not cause rapid death.
:
Thus there are three factors which assist in the disappearance of the spirochete, at all events temporarily, namely, the elevation of the temperature, the formation and development of the natural immunising power of the blood of the patient, and, lastly, the peculiar parti- cular action of the spleen.
Their Absence after Death. The spirochetæ are not found in the blood of a patient who dies of Relapsing fever, whether death takes place during the febrile period or during the afebrile period. This is the general rule.. Exceptions very exceptionally occur.
In my case I could find nothing whatever in the blood, the bone marrow, or any of the organs. What happens when they disappear, and where do they disappear? I grew them for 11 days in a solution of normal saline. They did not apparently increase in numbers, but they lived and were active. On the 12th day haemolysis set in, and on the 13th day only granular debris could be found on examination. Hence I conclude that a bactericidal action of the blood is produced as a result of the secretion of some toxin by these spirilla, and that when this becomes powerful enough it causes a disintegration of them without, however, the accompaniment of hemolysis in the living body.
Methods of Transmission.-What is the method by which these spirochetæ are con- veyed from an infected to a non-infected person? It is known of course that Relapsing Fever is a very infectious malaiy (and it is one of the notifiable diseases in Hongkong), and that widespread epidemics arise and are propagated from small foci.
Various experiments have been conducted with the object of demonstrating how this transmission of the disease is effected, and what animals are susceptible to it. I carried out a few experiments with this view and summarise the results :-
Page 465Page 466