The Democratic banner. (Mt. Vernon, Ohio) 1898-192?, 1915-11-09
HOOP AND MJUIH DISEASE
AND THE SERUM TESTS

manifested symptoms OF the disease.
All the animals were, however, slaugh-
tered at once. The three he. DIS in
which no disease was found were also
slaughtered without waiting to see
whether they would subsequently de-
velop the disease or not. This measure
was necessary on account of the risk
that the disease might be spread by
the animals while in the incubative
stage. AS a result Of the precaution no
further cases have been reported from
Michigan, Minnesota or Indiana.
In addition to these measures adopt.
ed to control the spread of the disease,
samples of the serum actually used
were procured from the owners OF the
infected herds and also samples of the
remaining stock of the Chicago Ser.
um Company. Pigs and calves, the ami
mails which are most susceptible to
foot-and-mouth disease, were inoculat-
ed with these samples. The results
were again negative and after two SER
les Of tests had been made. the United
States Public Health Service was ask.
ed to conduct a third series. This also
was negative.
Up to this time, therefore, four ser
les of tests had been made in which
total of So animals had been used.
None of these 81 animals developed
fonf.o nd m, oufh dtuaoso aud tho ,ooo,,
lation afforded no evidence that the
serum was In any way contaminated.
Each subsequent series apparently on
ly confirmed the original test made be-
fore the serum was permitted to be
placed upon the market. The fact re-
mained. however, that herds treated
commercially with the serum had de-
veloped foot-and.mouth disease. A
fifth test therefore was made and ten
days after incubation, the sixty-second
animal which had been used in the
tests, a calf which had received thir-
ty cubic centimeters, developed char
acteristic LESSONS. The diagnosis of
foot-and-mouth disease was subse-
quently confirmed by the incubation of
other animals with material from the
infected calf.
This Is regarded as proof that the
suspected serum actually was infect
ed. Why the standard tests used on 81
animals failed to reveal this fact is a
matter for scientific investigation and
the bacteriologists of the Department
are now at work upon the problem. At
the time OF manufacture, One-half of
one per cent OF carbolic acid was
mixed with the serum to act as pre-
servative. 1t is now believed that
the carbolic acid, acting as germi-
eide, may have attenuated or partially
destroyed the virus to such an extent
that what have previously been con.
sidered safe tests failed to establish
! the presence of the infection. 1t is
also possible that the virus instead of
being disseminated throughout the en-.
/ tire mass of serum. may have become
agglutnated. This has been known
to occur with germs OF other diseases
The result would be the formation in
the serum fluid of isolated clumps of
foot-and-mouth disease virus, while the
bulk of the serum remained free from
these tiny masses. If this were the
case, it Is obvious that certain animals
inoculated with the serum would de.
yelop foot-and-mouth disease and 9th
ers would escape. Up to the present
1t should be stated, scientists have not
been able to identify the germ of foot
and.mouth disease although the econ
omic Importance Of the plague in Eu
rope has caused It to be studied ex
haustively for many years.
In the Department, experiments are
now being vigorously prosecuted with
u view to discover means of treating
serum at the time OF its manufacture
which effectually will kill the virus OF
foot-and-mOuth disease. The results
SO far attained are promising and the
Department hopes that a successful
method will be evolved shortly. In the
meantime all the infected serum In
the hands of the Chicago Serum Com
pany has been detroyed without com
pensation. All other serum manufac
tured In Chicago. which 1t was believ
ed might contain possibilities OF dan
ger. has likewise been destroyed. Fur
thermore. the Department Is prohibit
Ing shipment Of any serum from Ii
censed establishments In the districts
that are under quarantine for foot-and
mouth disease.
The problem OF producing serum
which will be effective in controlling
hog cholera and at the same time will
be absolutely safe In general use l.
complicated by the fact that the De
partment OF Agriculture has no author
J ity over serum plants which dispose o
their products exclusively in the State