At the recent Medical Congress in London, Professor Klebs undertook to
answer the question: "Are there specific organized causes of disease?"
A short historical review of the various opinions of mankind as to the
origin of disease led, the speaker thought, to the presumption that
these causes were specific and organized.
If we now, he said, consider the present state of this question, the
three following points of view present themselves as those from which
the subject may be regarded:
I.--We have to inquire whether the lower organisms, which are found in
the diseased body, may arise there spontaneously; or whether even they
may be regarded as regular constituents of the body.
II.--The morphological relations of these organisms have to be
investigated, and their specific nature in the different morbid
processes has to be determined.
III.--We have to inquire into their biological relations, their
development inside and outside the body, and the conditions under which
they are able to penetrate into the body, and there to set up disease.
_First_.--With regard to the first question, that of the possibility of
spontaneous generation, the speaker gave a decided negative.
_Second and third_.--There is in microscopic organisms a difference of
form corresponding, as a rule, to difference of function. The facts
regarding these various lower forms are briefly reviewed.
"Three groups of hyphomycetae, algae, and schizomycetae, have been
demonstrated to occur in the animal and human organism in infective
diseases. Their significance increases with the increase of their
capacity for development in the animal body. This depends partly upon
their natural or ordinary conditions of life, but partly also, and that
in a very high degree, upon their power of adaptation, which, as Darwin
has shown, is a property of all living things, and causes the production
of new species with new active functions.
"1. The hyphomycetae, on account of their needing an abundant supply
of oxygen, give rise to but few morbid processes, and these run their
course on the surface of the body, and are hence relatively of less
importance. It will be sufficient here to refer to the forms, achorion,
trichophyton, oïdium, aspergillus, and the diseases produced by them,
favus, ringworm, and thrush, to show this peculiarity. Nevertheless, we
see that these organisms also (as was proved by the older observations
of Hannover and Zenker) may, under certain circumstances, penetrate into
the interior of the organs. Grawitz, moreover, has recently shown that
their faculty of penetrating into the interior of the organism, and
there undergoing further development, depends on their becoming
accustomed to nitrogenous food.
"2. Only one of the algae, viz., leptothrix, has as yet acquired any
importance as a producer of disease. It gives rise to the formation of
concretions, and that not only in the mouth, but also, as I have shown,
in the salivary ducts and urinary bladder.
"Another alga, the sarcina of Goodsir, may indeed pass through the
organism, without, however, producing in its passage either direct
or indirect disturbances. It seems more worthy of note that many
schizomycetae, and especially the group of bacilli, are evidently nearly
allied to the algae in their morphological and vegetative relations--so
as to be assigned to this class by several authors, and especially by
Cienkowski.
"The schizomycetae furnish, without doubt, by far the most numerous
group of infective diseases. We distinguish within this group two
widely different series of forms, which we will speak of as bacilli and
cocco-bacteria respectively. The former, which was first exhaustively
described by Ferdinand Cohn, and the pathological importance of which,
especially in relation to the splenic disease of cattle, was first shown
by Koch, consist of threads, in the interior of which permanent or
resting-spores are developed. These spores becoming free, are able,
under suitable conditions of life, again to develop into threads. The
whole development of these organisms, and especially the formation
of spores, is completed on the surface of the fluids, and under the
influence of an abundant supply of oxygen.
"The number of affections in which these organisms have been found,
and which may be to a certain extent produced artificially by the
introduction of these organisms into healthy animal bodies, has been
largely increased since the discovery of Koch, that the bacteria of
splenic fever (anthrax) belong to this group. Under this head must be
placed the bacillus malarise (Klebs and Tommassi-Crudeli), the bacillus
typhi abdominalis (Klebs, Ebert), the bacillus typhi exanthematici
(Klebs, observations not yet published), the bacillus of hog-cholera
(Klein), and, finally the bacillus leprosus (Neisser). It would exceed
the time appointed were I to attempt to describe these forms more
minutely. This may, perhaps, be better reserved for discussion and
demonstration.
"Alongside of these general infective diseases produced by bacilli,
local affections also occur, which indicate the presence of these
organisms at the point where disease begins. As an example of these
processes, which probably occur in various organs, I would mention
gastritis bacillaris, of which I shall show you preparations. In this,
we can trace the entrance of the bacilli into the peptic glands, as well
as their further distribution in the walls of the stomach, and in the
vascular system.
"The second group of the pathogenetic schizomycetae I propose to call,
with Billroth, cocco-bacteria, because they consist of collections of
micrococci, which are capable of transforming themselves into short
rods. The former usually form groups united by zoögloea; by prolongation
of the cocci rods are formed, which sprout out, break up by division
into chains, and further lead again to the formation of resting masses
of cocci. I distinguish, further, in this group, two genera--the
microsporina and the monadina; in the former of which the micrococci are
collected into spherical lumps, in the latter into layers. The one class
is developed in artificial cultivation fluid, the other on the surface.
The former requires a medium poor in oxygen, the latter a medium rich in
oxygen, for their development.
"Among the affections produced by microsporina, I reckon especially the
septic processes, and also true diphtheria. On the other hand, to the
processes produced by monadina belong especially a large series of
diseases, which according to their clinical and anatomical features,
may be characterized as inflammatory processes, acute exanthemata, and
infective tumors, or leucocytoses. Of inflammatory processes, those
belong here which do not generally lead to suppuration, such as
rheumatic affections, including the heart, kidney, and liver affections,
which accompany this process, sequelae which, as is well known,
lead more especially to formation of connective tissue, and not to
suppuration. Here, also, belong croupous pneumonia, the allied disease
erysipelas, certain puerperal processes, and finally, parotitis
epidemica, or mumps.
"Among the acute exanthemata, the following may, up to the present time,
be placed in this group; variola-vaccina, scarlatina, and measles.
"The group of infective tumors is represented by tuberculosis, syphilis,
and glanders. Throughout the whole group of cocco-bacteria the
demonstration of organisms in the diseased parts encounters difficulties
which vary considerably in the different kinds."
The speaker concluded by describing the methods (now well known) by
which the powers of the different organisms are tested.
He also referred to Pasteur's, Chauveau's, and Toussaint's recent
experiments.
His conclusion was that the specific communicable diseases are produced
by specific organisms.
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