7.36 The Current State of the Struggle against Tuberculosis
Robert Koch
Robert Koch
Nobel Lecture
Nobel Lecture, December 12, 1905
Twenty years ago, tuberculosis,
even in its most dangerous form, consumption, was still not considered
infectious. Of course, the work of Villemin and the experimental investigations
by Cohnheim and Salomonsen had already provided certain clues which suggested
that this conception was false. But it was only with the discovery of the
tubercle bacillus that the aetiology of tuberculosis was placed on a firm
footing, and the conviction gained that this is a parasitic disease, i.e. an infectious,
but also avoidable one.
In the first papers concerning
the aetiology of tuberculosis I have already indicated the dangers arising from
the spread of the bacilli-containing excretions of consumptives, and have urged
moreover that prophylactic measures should be taken against the contagious
disease. But my words have been un-heeded. It was still too early, and because
of this they still could not meet with full understanding. It shared the fate
of so many similar cases in medicine, where a long time has also been necessary
before old prejudices were overcome and the new facts were acknowledged to be
correct by the physicians.
However, quite gradually the
understanding of the infectious nature of tuberculosis then spread, taking root
ever more deeply, and the more the conviction of the dangerous nature of
tuberculosis made headway, the more was the necessity of protecting oneself
against it thrust on people.
First of all, efforts directed
to this end attracted attention in papers giving information and warnings.
Shortly after this there came into existence, provoked by the successes which
Brehmer obtained with the dietetic-hygienic treatment of patients with lung
complaints, sanatoria for consumptives, to which were added convalescent homes,
seaside resorts, out-patient clinics and similar establishments. An extremely
rich corporate activity developed. International congresses took place. In some
places the obligation to give notice to the authorities was introduced, on an
optional or compulsory basis. In some states and cities thoroughly worked-out
laws were enacted against the tuberculosis menace. Hardly a country remains
where, in one way or another, the struggle against tuberculosis has not been
taken up, and it is extraordinarily gratifying to see how the campaign is now
waged quite generally and with considerable vigour against this dangerous
enemy.
But taken as a whole, all these
efforts were quite dissimilar in character, though they all pursued the same
aim, but chose quite different approaches to it. In one country people wanted
to achieve everything by instruction, in another they hoped to be able to
remove tuberculosis by therapeutic measures, and again in another people turned
exclusively against the supposed menacing dangers of bovine tuberculosis. Of
late a certain adjustment has, indeed, made its appearance, in so far as
individual countries no longer proceed in quite such a biased way as before,
and one takes over from another whatever seems to be well tried in the way of
means of defense. However, amidst the persistently great variety in the ways
and means of combating tuberculosis, it is yet necessary to ask what measures
do indeed best satisfy the scientific requirements and general findings in the
fight against contagious disease.
But, before we come to answer
this question, we must make perfectly clear to ourselves how infection is
brought about in tuberculosis, i.e. how the tubercle bacilli invade the human
organism; for all prophylactic measures against an infectious disease can only be
directed towards preventing the germs of disease from invading the body.
In relation to tuberculosis
infection so far only two possibilities have offered themselves: first,
infection by tubercle bacilli which come from tuberculous people, and second,
by those that are contained in the milk and meat of tuberculous cattle.
As a result of investigations
which I made together with Schütz into the relation between human and bovine
tuberculosis, we can dismiss this second possibility, or look upon it as being
so small that this source of infection is quite overshadowed by the other. We
arrived in effect at the conclusion that human and bovine tuberculosis are
different from one another, and that bovine tuberculosis cannot be transmitted
to a human. With regard to this latter point, I would, however, like to add, so
as to obviate misunderstandings, that I refer only to those forms of
tuberculosis which are of some account in the fight against tuberculosis as an
epidemic, namely to generalized tuberculosis, and, above all, to consumption.
It would take us too far here, if I were to go more closely into the very
lively discussion which has developed over this question; I must keep this for
some other occasion. I would just like to observe in addition to this that the re-examination
of our investigations, which was undertaken in the Imperial Department of
Health in Berlin with the greatest care and over a wide area, has led to a
confirmation of my view, and that the harmlessness for humans of the bacilli of
"pearl disease" is directly proved, in addition, by inoculating
humans with material from it, as was done by Spengler and Klemperer.
Consequently, only the tubercle bacilli coming from humans are of consequence
in the battle against tuberculosis.
But the disease does not in all
tuberculous patients take such forms that tubercle bacilli are discharged to a
noteworthy extent. It is really only those suffering from tuberculosis of the
larynx and lungs who produce and disseminate considerable quantities of
tubercle bacilli in a dangerous way. But it is as well to note that not only is
the secretion of the lung called sputum dangerous by reason of its bacillary
content, but that, according to the investigations of Flügge, even the smallest
drops of mucus expelled into the air by the patient when he coughs, clears his
throat, and even speaks, contain bacilli and can cause infection.
We come therefore to this
fairly sharp demarcation, that only those tuberculous patients comprise an
important danger to the people around them, who suffer from laryngeal or
pulmonary tuberculosis and have sputum which contains bacilli. This type of
tuberculosis is designated "open" as opposed to "closed",
in which no tubercle bacilli are discharged into the environment.
But even in patients with open
tuberculosis there are still distinctions to be made regarding the degree of
danger due to them.
It can indeed very often be
observed that such patients live for years with their families, without
infecting any of them. Under some circumstances, in hospitals for consumptives
infections among the nursing staff can be totally absent, or indeed so rare
that it was even thought that in this was to be seen a proof of the
non-contagiousness of tuberculosis. If, however, such cases are looked into
more thoroughly, then it turns out that there are good reasons for the apparent
lack of contagiousness. In such cases one is dealing with patients who are very
careful where their sputum is concerned, who value the cleanliness of their
home and their clothing, and in addition live in well-aired and well-lit rooms,
so that the germs, taken up in air, can be rapidly carried away by the flow of
air or killed by light. If these conditions are not fulfilled, then infection
is not lacking in hospitals and the homes of the well-to-do, as experience
teaches us every day. It becomes more frequent, the more unhygienically the
patients handle their expectoration, the more there is a lack of light and air,
and the more closely the sick are crowded together with the healthy. The risk
of infection becomes particularly high if healthy people have to sleep with the
sick in the same rooms, and especially, as still unfortunately happens with the
poorer section of the population, in one and the same bed.
In the eyes of careful
observers, this sort of infection has acquired such importance that
tuberculosis has been called plainly, and quite justly, a disease of
accommodation.
To recapitulate briefly, the
circumstances relating to infection in tuberculosis are as follows.
Patients with closed
tuberculosis are to be regarded as quite harmless. Also people suffering from
open tuberculosis are harmless as long as the tubercle bacilli discharged by
them are prevented from causing infection by cleanliness, ventilation, etc. The
patient only becomes dangerous, when he is on his own unclean, or when, as the
result of advanced disease, he becomes so helpless that he can no longer see to
the adequate disposal of the expectorated material. At the same time the risk
of the healthy being infected increases with the impossibility of avoiding the
immediate neighbourhood of the dangerous patient, thus in crowded rooms and
most particularly when these are not only overfull, but are badly ventilated
and inadequately illuminated as well.
I now come to the problem of
examining the measures currently in use to see to what extent they take account
of the aetiological factors, as I have just described them. If I prefer to
confine myself in this to the conditions in
The starting-point in the fight
against all contagious diseases is the obligation to report, because without
this most cases of the disease remain unknown. So we must make this a
requirement for tuberculosis as well. But in this particular disease, out of
consideration towards the patients, there has been some reluctance to require
the notification to be given by the doctors or those otherwise under an
obligation to do so. However with the correct realization that it is not just a
question of considerations applying to the sick here but also of the protection
of the healthy, the obligation to notify has been introduced in several places,
at first on an optional basis, and then, when it transpired that the
disadvantages feared did not materialize, on a compulsory basis. Since,
therefore, experience has already testified to the feasibility of registration
in tuberculosis, it should be introduced everywhere. It can, however, without
prejudicing the objective, be restricted to those cases which constitute a
danger to their acquaintances and so to patients with open tuberculosis in
hygienically unfavourable conditions.
If we lay the responsibility for
notification on doctors, then we must at the same time ensure that they can
judge the cases in question correctly, in particular with respect to the
presence of open tuberculosis. This can only happen with the establishment of
centres where the patient's sputum is examined without cost for tubercle
bacilli. These could exist independently, or, what is perhaps more practical,
in association with hospitals, policlinics, or with social-welfare centres,
which will be mentioned later. So far such places for investigations have
already been established in some countries, but in far too small numbers. It
will be necessary in future to take this need into consideration adequately.
Now what is to happen to the
patients who are to be regarded as dangerous, after they have been identified?
If it would be possible to
place all these people together in hospitals and thus make them relatively
harmless, then tuberculosis would decrease very rapidly.
But this, for the moment at
least, is out of the question. The number of people with tuberculosis for whom
hospital treatment would be necessary is in
However, it is by no means
necessary that all tuberculous patients should be brought into hospitals at
once. We may count on a decrease in tuberculosis, albeit a slower one, if a
considerable fraction of these patients are admitted into suitable
institutions.
In connection with this, let me
remind you of the exceptionally instructive example of the fight against
leprosy in
One should proceed in the fight
against tuberculosis along the lines suggested by this example. And, if it is
not possible to deal with all consumptives, then as many as is humanly
possible, including the most dangerous, i.e. those who are in the final stages
of consumption, should be accommodated in hospitals.
In this respect, however,
already there is more happening in some places than is usually supposed. In the
city of
The number of consumptives who
are brought in this way into a situation where they can no longer spread
infection, is indeed fairly considerable and cannot remain without influence on
the progress of this infectious disease.
In relation to this, I would
like to draw your attention to a phenomenon which deserves the greatest
consideration. This is the uniform and significant falling-off of the mortality
due to consumption in several countries.
In
It is difficult to say what has
brought about this characteristic behaviour of tuberculosis in the countries
named. One supposes that several factors have worked together. The improvement
in the situation of the lower strata of society, in particular with regard to
housing conditions, and the improved knowledge of the risk of infection, which
dissuades the individual from exposing himself unsuspectingly to infection any
more, have certainly played their part in bringing about the decline in
tuberculosis. But I am firmly convinced that the better provision for
consumptives in the terminal stages, namely their accommodation in hospitals,
which is happening to a relatively large extent in
From this we must draw the
lesson that the greatest emphasis must be placed on these measures in the fight
against tuberculosis, namely on the accommodation of consumptives in suitable
institutions, and much more care than before should be taken to insure that
consumptives do not die in their homes, where they are moreover mostly in a
helpless state, without adequate nursing.
When consumptives are no longer
turned away, as before, by the hospitals as incurable, and when, on the
contrary, we afford the best treatment conceivable and free of charge, and can
even offer the prospect of a cure in a few cases, when in addition provision is
made for their families during the illness, then there will be no need for any
compulsion at all to make many more of these unfortunate sick people come to
the hospitals, than is already happening now.
Now I am going to turn to the
discussion of a measure which will combat tuberculosis in quite a different
way. This is the matter of sanatoria. Sanatoria were established in the
expectation that a great part, perhaps even the majority of consumptives can be
cured in them. If this supposition were to be correct, then sanatoria would
decidedly be one of the best weapons in the struggle against tuberculosis. But
there is a good deal of argument as to the results of the sanatoria. By one
side it is affirmed that they have had up to 70% of successful cures, while the
other side disputes every success. Now it must be conceded that the 70% of
successes does not refer to real cures, but only to the recovery of earning
capacity. But from the standpoint of prophylaxis there is no gain in this,
since a patient who is not completely cured but is only improved to the extent
that he is capable of earning again for a while, later develops the condition
of open tuberculosis, and succumbs to all its consequences, as were depicted
earlier.
The reason for the relatively
small number of real cures obtained in the sanatoria evidently lies in the fact
that the duration of the treatment in these institutions is much too short, and
that very many of the patients accepted are in such a far-advanced stage that
the dietetic-hygienic treatment is no longer sufficient to cure them. Many
doctors in sanatoria have also correctly recognized this already. For this
reason they take care that only such patients are accepted as are in an early
stage of tuberculosis, and in addition to the sanatorial treatment they
administer tuberculin preparations, in order to achieve swifter, and, in
particular, more lasting cures. In this way considerably better results than
before have already been obtained in several sanatoria, and it is to be
supposed that sanatoria, if they go on in this way, will make quite a
substantial contribution to the fight against tuberculosis, at least in
Germany, where already about 30,000 patients are now getting treatment each
year in over a 100 sanatoria.
If in this way the greatest possible
proportion of consumptives in an advanced state are taken care of by admission
into the hospitals, and if the earliest stages of the disease are taken care of
by the sanatoria, then there is still a large number of patients left, who must
at all events be taken into account too. These are the ones in advanced stages
of the disease who remain at home, and those consumptives whose illness has
progressed too far for treatment in the sanatoria, but yet still not so far
that they are incapable of working and have to go to a hospital. If these
tuberculous people, whose numbers, as I have said, are truly considerable, are
abandoned to their fate, then a great gap in the battle against tuberculosis
would result from this.
To have filled in this gap is
the merit of Calmette, who had the happy idea of taking care of this category
of patient with the out-patient clinics which he had organized. This stimulus
provided by Calmette has met with approval everywhere, especially in
In such ways these institutes
provide the poor consumptives with a true welfare service, and on this account,
with full justification, they have been called "social welfare
centers". I consider these arrangements to be one of the most powerful
weapons, if not the most powerful, which we can bring into use against
tuberculosis, and I believe that the social welfare centres, if, as is to be
hoped, they spread over the country in a close network, are destined to
exercise an extremely beneficial effect.
The measures which have been
mentioned so far, namely duty to registrate, hospitals, sanatoria, and social
welfare centres, comprise the heavy artillery in the fight against
tuberculosis. But besides these, other lighter weapons are available to us,
which can not produce any such decisive effect on their own, but whose aid we
cannot dispense with.
Among these I mention in the
first place all the efforts which have been directed at instructing the people
on the danger of tuberculosis by means of popular publications, lectures,
exhibitions and other media of that kind, and at keeping alive the interest of
all social classes in the fight against tuberculosis. Later, when the social
welfare centres are available in sufficient numbers, instruction will be
dispensed on such a generous scale from these institutes, that we will hardly
need special arrangements for this any more then; but for the present we cannot
dispense with them.
In addition the numerous
societies and associations provide very valuable help, which participate in the
fight against tuberculosis by supplying money with which to found sanatoria and
convalescent homes, to endow free beds, and to support the families of poor
consumptives, etc.
We should not close our eyes to
the fact that the fight against tuberculosis needs quite considerable financial
resources. Basically it is only a question of money. The more free beds for
consumptives that are endowed in well-equipped and well-run sanatoria and
nursing-homes, the more adequately the families of the tuberculous are
supported, so that the sick are not dissuaded from going into hospital out of
concern for their relatives, and the more social welfare centres are set up,
the more rapidly will tuberculosis decrease in importance as a wide-spread
infectious disease.
Since, however, it is hardly to
be expected that communities, which have already now often made generous
sacrifices on behalf of their tuberculous members, will be able to meet all the
requirements in this respect in the immediate future, it follows that help
coming from private quarters is much to be desired. But care must be taken that
the funds raised by societies and associations, or made available by individual
benefactors, do not find employment on matters of secondary importance, but
that they should be used to further the most effective measures, above all the
institutes for the accommodation of the sick and the social welfare centres.
In the fight against
tuberculosis, as it has been depicted so far, hardly anything remains to be
done by the State, and yet, for its part, it can contribute to it in an
effective way. This can happen by the State introducing legislation for
compulsory registration for tuberculosis, which already is in force for all the
other important wide-spread infectious diseases. In several countries this has
already happened, and it is to be hoped that the other civilized countries will
soon follow this example. Often a legislative foundation as well has been
required for the compulsory isolation of such sick people, who are particularly
dangerous to those surrounding them. According to my experience in the fight
against contagious diseases we can, however, dispense with these stem measures.
If we only make the admission of consumptives into suitable hospitals easier in
the way indicated earlier, then we will achieve all we need.
But the State can interfere
particularly usefully in one respect, namely as regards the improvement of
unfavourable housing conditions. Private action is virtually powerless against
this nuisance, while the State can easily remedy the situation with suitable
laws.
If we look back on what has
happened in recent years in the fight against tuberculosis as wide-spread infectious
disease, then we cannot help but gain the impression that quite an important
beginning has been made.
The struggle against
tuberculosis is not dictated from above, and has not always developed in
harmony with the rules of science, but it has originated in the people itself,
which has finally correctly recognized its mortal enemy. It surges forward with
elemental power, sometimes in a rather wild and disorganized fashion, but
gradually more and more finding the right paths.
The struggle has caught hold
along the whole line and enthusiasm for the lofty aim runs so high that a
slackening is no longer to be feared.
If the work goes on in this
powerful way, then the victory must be won.
From Nobel Lectures, Physiology or Medicine 1901-1921,
Elsevier Publishing Company,
