Browning chief. [volume] (Browning, Mont.) 1941-1953, 1941-07-11

made as a result of the joint study
carried on with the Montana livestock
sanitary board and the Montana fish
and game commission, was the discov-
cry in certain Montana streams of the
occurrence Of the bacterium which
causes tularaemia Just how dangerous
contaminated stream water may be as
a source of human infection is still
to be determined, but the evidence
thus far obtained suggests that the in
fictitious agent of tularaemia is most
likely to be found in stream water dur
ing the fall, winter and early spring,
i. e., during the seasons of the year
when there is less likelihood of such
water being used by picnickers. camp
ers and other persons who are inter-
ested in outdoor life.
Relapsing Fever
Another disease of particular inter-
est to the western United States Is
relapsing fever. This disease was not
known to be endemic in the United
States until about 1880, when the first
evidence that it was a native disease
was obtained as result of cases &C.
curing in Texas. RelapSing fever is
another tick-transmitted disease, but
the group of ticks that carry this in
lection are known as the "Soft-shelled"
ticks which feed and drop off quickly
after the manner of bed bugs and do
not remain attached for days as do
the "hard-shelled" ticks that transmit
spotted fever and tularaemia. Since
1880 this disease has been found to
occur in most of the western and in
several of the central states. At least
two, and probably three, different spe-
cieS of ticks are concerned in its trans
mission. Many of the discoveries con-
corning this disease in the United
States and the ticks that transmit it
here have been made at the Rocky
Mountain laboratory, particularly by
DR.. Gordon E. Davis. Relapsing fever
is most prevalent in Texas and Cali
fornia, but new foci are being found
each year. Wyoming and Montana are
the only Rocky mountain states from
which authentic human cases have not
been reported although infected ticks
have been found in both. The danger
of infection is greatest in poorly con-
structed cabins and summer homes to
which rodents that carry the ticks can
gain easy entrance.
Study Bubonic Plague
Bubonic plague is another disease in
which the laboratory is interested. This
disease was brought into the San Fran
cisco bay region from the orient about
1900 and shortly thereafter the plague
bacillus, which most people are in
clined to associate with rat populations
in cities, became established in the
local rodent population, particularly in
ground squirrels. An intensive fight
against this infection was carried on
for number OF years and those as
ISOLATED with its study became con-
vinced that there was little danger of
its spread to other parts of the country.
However. in 1885, DR.. William L. Jelli-
son and other members of the labor
atory staff found the sylvatic plague,
as plague in wild rodents Is called,
was decimating the ground squirrel
population in southwestern Montana.
Thus plague was found to be endemic
in native rodents hundreds of miles
east Of any point where it had previ-
ously been found. Since that time, 1t
has been found to be present in ground
squirrels and other rodents in all the
Pacific coast and Rocky mountain
states. It now appears that during
the past four decades, there has been
a gradual insidious outward spread Of
this infection through the medium of
rodents from the original endemic area
near San Francisco bay until 1t Is now
present in nature over . vast region.
Plague is acquired by the bites Of
Heas rather than ticks and to some
extent through the handling of in
fected rodents and perhaps occasion
ally from scavenger birds that feed ON
the carcasses Of rodents dead Of this
disease. However, with the present-day
knowledge Of preventive measures
there Is no apparent occasion to fear
that there will be any extensive out
breaks. Nevertheless, it is . potential
MANAGE that should INST be minimised
Human cases 1t present are not nu-
mcrous, and though there are some
fatalities, tho evidence suggests that
tho strains now resident IN nature IN
Tie wet are not q maximum virul-