The Republican. [volume] (Oakland, Md.) 1877-current, 1906-06-28
TRANSMISSION OF TUBERCULOSIS
Dangers Of Infection From Dairy
Cows to Persons Using the niIk.

troubling the medical profession for
many years. Ever since Villemin, a
French scientist, demonstrated the in
fectiousness of tuberculosis in the COS,
the question of human infection from
animal sources has been receiving con-
slant attention. Some of the foremost
scientists of the last half century have
devoted years to its study and investi-
cation and it is indeed strange that no
conclusive results have been obtained.
The investigation has produce an abund-
ance of information as to the nature,
habits and wide range of infection of the
disease but no positive evidence has yet
been produced that the disease is COM
municable from animals to man through
natural or normal means. Direct ex-
perlments to show whether man can be
infected with animal tuberculosis are
for obvious reasons impossible and the
deductions from clinical observation
are uncertain and often misleading.
Opinions must therefore be based upon
| the general knowledge of the behavior
of tubercle bacilli as they are studied.
lnnumerable experiments have shown
that human bacilli will infect 'other
species such as dogs, sheep, goats, cat
tie and even birds and fish. These in
fections were all made by direct inocu-
latlon and not by normal means of in
lection was complete in a very large
number of cases, there is still doubt as
to the tuberculosis of man and other
animals being one and the same disease.
The difficulty in Identification is the dis
ease is increased by the fact that differ
ences in the tubercle bacilli of different
animals are too slight to be character
istic. Hence the only available means
of determining whether or not bovine
tuberculosis is communicable to other
animals through the natural source of
consumption of milk is by experimental
ton on the lower animals. This is the
line followed by the present-day scier-
fist.
The report of the Bureau of Animal
Industry, Department of Agriculture,
for 1904, contains a discussion of such
experiments carried on by DR.. E. C.
Schroeder and ". E. Cotton, superin-
tendent and expert assistant, respec-
lively, at the government experiments,
guinea pigs and hogs were used. These
animals had been raised at the station
and as far as known were entirely free
from disease. The guinea pigs used
were divided into lots A. B. C. and d.
Lot A received tra-obdominal mice
tons of milk from tubercular cows.
Lot B was fed on the milk of tubercu-
lar cows. Lot was confined in cages
fasten to the walls of the box stalls oc-
cupied by tubercular cattle, at right
angles to the walls against which the
hangers were located. The cages had
open sides and closed bottoms. They
were placed above the level of the cow
head when in position of coughing
This form of exposure was called'room
exposure and was supposed to cores
pond to the occupancy of rooms in COM
mon by healthy and tuberculag-dis-
eased individuals. Lot D was confined
in cages constructed under the hangers
in stalls occupied by tubercular cattle.
The arrangement was such that small
amount of feed sifted from the hangers
to the cages while the cattle were eat
ing, This was called manger exposure
and was calculated to give the best pos
sible condition for infection from ex-
posure to diseased individuals.
The first COW used in the experiment
had been SO with tuberculosis for several
years and at the time of her death was
s emaciated and suffering so severely
with respiratory difficulties that it
would have been cruel to prolong her
life. The autopsy showed an advanced
generalized tuberculosis of the abdomi-
nal and thoracic organs. The total
amount of disease was so great that
it was difficult to understand its CON-
patibility with the persistence Of life.
The udder and milk glands were unaf-
fected. Eight guinea pigs were fed
milk from COW No. for a period of 100
days. On post norton examination
all were found to be in excellent cond.-
ton and free from all LESSONS of disease.
Five guinea pigs were given room ex-
posture to cow No. and none develop
ed lesion Of disease. Eight guinea
pigs were given manger exposure to
this cow and one was found upon post
mortem examination to be effected with
tuberculosis of liver, spleen mesenteric
glands: the others were free from
LESSONS of disease.
Cow No. was still alive when the
report was made, but showed all the
common symptoms of generalized dis
ease-emaciation, weakness, cough, etc.
Five guinea pigs were fed or the milk
from COW No. and were found on post
norton examination to be in excellent
condition and free LESSONS of disease.
Four guinea pigs were given manager
exposure and none developed LESSONS of