Great Falls tribune. [volume] (Great Falls, Mont.) 1921-current, 1922-07-12
RODENTS ADD
TO MENACE OF
FEVER TICKS
Doctor Says Gophers Response.
BILE for Many Cases in
the Bitter Root.

Addresses by Drs. r. r. Parker and
r. r. Spencer of the United States
public health service on the condition
of spotted fever in the Bitter Root
valley of Montana. near Hamilton,
were of chief interest ION Tuesday
mornings program of the public health
administration section of the fourth
annual convention Of the State Public
Health association in the Junior high
school.
DR.. Parker discussed THE Entomo-
logical Phase of the spotted fever in
~vestigationS now being conducted. and
DIR. Spencer gave an address on The
Psychological Phase
DIR. Parker said that in 1915 there
were 81 cases of spotted fever in Mon
tana and this year there are 90. In
1915. there were also cases of this
disease caused by virtually the same
conditions in Wyoming, California. Ida
no, Colorado, Nevada. South Dakota,
Washington and Utah. This year. he
said, he knew of six cases in n local
ity alone in the state of Washing
ton.
In eastern Montana. there were sew
eral cases in 1915, but little trouble
has been experienced there lately. The
principal cause of this disease seems
to be of some natural effect, which is
vet to be determined. 1t is expected
that soon it will be possible to sue
c~essfully vaccinate people against spot
ted fever. he stated.
DR.. T.. b. Beatty, state health COM
missioner of Utah. supplemented the
two addresses on spotted fever by a
description of the work being carried
on in Utah against the disease.
DIR. A. Dolan. assistant medical di-
rector of the United States Veterans
bureau at Helena. spoke briefly on
The Limitations and Medical Care of
United States War Veterans"
DR.. Spencer's address follows:
Offers Many Problems
The problems involved in working
out a successful method Of control or
prevention of Rocky mountain spotted
fever are many and varied. For this
reason. our work was initiated last
spring on a rather broad basis. At
the present time. however. the i~nyesti-
cation has resolved itself into two main
lines: first. the study Of the relation
ship the disease bears to ticks and
animals in nature. with the idea of
evolving a practical method of control
VI tiouiIutlou ol tut ulStdSt dfIlOi
animals; and second. the study Of the
phases Of the virus occurring in ticks
with the hope of so modifying or alter
mating the virus that il will lose its
infectivity and yet retain its immun-
lzing properties. ! am concerned here
only with the progress that has been
made along the latter line of study.
Rocky Mountain spotted fever falls
under the classification of insect borne
diseases or diseases dependent for their
transmission upon some intermediate
host. Other diseases Of this nature
are malaria. yellow fever. typhus fever.
bubonic plague. trypanosomiasis or
sleeping sickness, African tick fever.
cattle tick fever Of Texas and psut-
sugamushi or river fever of Japan.
From an chronological standpoint.
Rocky Mountain spotted fever may be
classed with those maladies which con
fer a lasting immunity. In this con-
~nection it resembles smallpox. typhus
fever. yellow fever. bubonic plague and
some others which confer immunity in
a less degree. With this in mind. il
always has been felt that the chance
of evolving a successful method Of i'm
munization is greater than in those
diseases which fall outside of this cate
CORY.
teSleu by lhnocutdti0n
Our original plan included. among
other things. the determination of the
percentage of infected ticks in nature
and the relation Of tick infectivity to
the number and species of animals.
Since tick infectivity can be tested
only by the innoculation of mascpratei
tick contents into susceptible animals
or by the feeding of ticks upon ami
mails. a preliminary experiment was de-
vised to indicate which Of the two
methods was the more reliable.
From this experiment it was
thought reasonable to conclude that
the innoculation of the tick contents
was the more reliable method of testing
infectivity of ticks. In this, !
however. we were greatly disappointed. !
Over 1.5D ticks secured from well
known infected areas in the Bitter
Root valley were innoculated into
guinea pigs without once producing |
spotted fever. Yet. it was surprising !
to find that. in many instances, these |
lamentations did produce immunity.
BY way of explanation, it may be said
that animals are considered immune |
when no fever follows an intraperito-
neal injection Of known virus.
"Our procedure was then changed so
that all drag ticks tdrag ticks are Sc
by dragging a white muslin flag
over the underbrushl were first fed
guinea pigs and if DO fever devel-