The Seattle star. [volume] (Seattle, Wash.) 1899-1947, 1916-07-28
Harmless
Tuberculin

iNt lN"ie . ~ va" 'NNH ~
piled To hundreds of thou
sands OF animals in this eoun-
try. Many of the best-known
herds of pure-bred cattle have
been tested yearly for two
decades. From this experience
the value of the test is we'll
established.
In making tubcrculin the
organism causing the disease
is employed. The tubercle
bacillus is grown in nutrient
solution until the maximum
growth is obtained. when the
solution with the organisms is
heated to the boiling point for
four hours. The growth is
then removed by filtration
through paper. The product
is evaporated to two-thirds OF
its original volume and one
half OF one per cent OF car
bolic acid is added. The prod
uet is then filtered through a
porcelain filter and is ready
for use.
Because the tubcrcie bacil-
lus is used in the preparation
of tubcrculin. many state
ments have been made in re-
gard TO injury that may re-
sui, from its injection. Ii has
often been claimed that tubcr-
eulin might produce tubcrcu-
losis in healthy animals. Such
statements are wholly without
foundation. II is impossible
for any tubercle baoilli to re-
main alive after the prolonged
heating. and thus the produc-
ton OF tuberculosis by its use
is wholly impossible. The adj
dition OF the carbolic acid
destroys other forms OF or
ganisms that may be intro
dueed during the iiltcring and
bot,ling OF the suberculin. II
is not proper to apply such
terms as Serum" or virus"
to tubereulin. II is simply an
extract OF the bacillus.
The firms making tubercu-
lin arc under the supervision
OF the Department OF Agrieul-
ture il their product is sold in
any state other than the one
in which il is made. This
supervision extends not only
to methods and equipment,
but determinations are also
made as to the value OF the
product by testing samples
purchased on the open mar
ket. Reports OF recent exam
nations have shown all sam
Piles examined to be satisfac-
tory. Without such control IL
is conceivable that methods
might be so altered as TO re-
duce the potency Of the prod
uet. The presence OF living
tuberclc bacilli in tuberculin
is inconccivable.
The appearance OF assesses
may sometimes follow the in
lection OF tubcrculin. Such a
result is due to careless and
dirty methods employed by
the person applying the test.
II the syringe has not been
cleaned and sterilizcd since it
was previously used, or If a
bottle has been opened and
then allowed TO stand some
DAYS before the tuberculin is
injected, trouble from ordin-
airy types OF infection may
follow.
Ii is often asserted that
tuberculosis has been trans
ferred from animal to animal
by the syringe, and the Their
momcters used in the test.
Such a thing is most improb-
able. Before beginning a test,
the syringe should be ster-
ilized by boiling or by the use
OF a disinfectant. The Their
mometers should be cleaned
and placed in a disinfectant.
There would seem to be little
use in disinfecting the needles
OF the syringe, or the Their
mometers, as they are used on
different members OF the same
herd. If any of the animals
are giving off the tubercle
bacilli, and thus an opportun-
ity is afforded for the organ
isms to be carried from ami
NAL to animal, there will be
a hundred factors in constant
operation in spreading the dis
easc-producing organisms, such
as direct contact, licking each
other. and air infection. The
part of the syringe and the
thermometer becomes of so
little importance as to be per-
fectly negligible.