Montana oil and mining journal., 1938-03-19

Recent warm spring weather, II 1t
continues, win bring Rocky Mountain
wood ticks out OF Information, launch
ing the season for what was once one
Of the vests most dreaded diseases
Rocky Mountain spotted fever.
What this season viii bring forGh Is
unpredictable, since spotted fever seems
to run in cycles. Some years there IS
q large number of cases and a high
percentage Of fatalities reported, while
the following year both the number OF
cases and the percentage Of fataltles
may decline.
During 1887, there were 237 cases Of
spotted fever recorded, with 80 cases
resulting fatally. Montana, Wyoming,
OREGON and Idaho reported the largest
number of cases and the most fatal
tiles, and approximately three-fourths
of all of the spotted fever cases in the
United States were found in these four
states. In 1885, one of the worst years
recorded for spotted fever, these four
states reported 304 cases and 49 IA
talities.
suit of patient work by comparatively
small group of scientists, persons who
might be exposed to ticks have a meas
lIre of protection. This protection Is a
vaccine, extensively and laboriously
prepared from the tissues OF injected
ticks in the only spotted fever research
laboratory in the United States, located
at Hamilton, Mont.
for the last 13 years but has been
used extensively only in recent years,
has proven to be full protection against
the less virulent strains Of Rocky
Mountain spotted fever, and materially
lowers the death rate in the highly
fatal type of the disease.
Doctor Discusses Vaccine
Discussing the vaccine in an article
which will soon be published IN the
Journal of the American Medical as
sociation, DR. r. r. Parker, director
of the laboratory at Hamilton, says:
"The United States public health
service vaccine for Rocky Mountain
spotted fever is prepared at and dis
tributed from, the Rocky mountain
laboratory of the National Institute OF
Health at Hamilton, Mont. Insofar as
it is available, 1t should be used by
those who live in or frequent danger
GUS areas. Unfortunately, this vaccine,
which is prepared from the tissues OF
infected Rocky mountain wood ticks,
Is difficult and expensive to produce
and at the present time 1t is possible
to manufacture annually enough for
only about 10000 persons. The cost ex-
ceeds $500 liter.
"This vaccine is used in two doses
of two cubic centimeters each, given
five days apart :. The data indicate
that the majority of persons are fully
protected against the less virulent
strains of Rocky Mountain spotted
fever, but that the average person is
only partially protected against the
highly fatal type. The maximum de-
gree of protection conferred is retained
for less than one year.
During the IS years in which the
vaccine has been in use, there have
been So cases in persons infected the
same year vaccine was administered.
Thirty-three cases of this group were
adults infected in the western Montana
area of highly fatal infection us were
laboratory cases, 18 infected spontan-
eously); three have proved fatal, a
case fatality rate of 900 percent. Dur
ing the same period in the same area
there have been so cases in nonvac-
cinated adults; 38 have died, case
fatality rate of rs percent. The fatality
rate In this area, therefore, has been
approximately 66 percent lower in the
Vaccinated group. The remaining rs
cases infected the same year as vac
cinated acquired infection in areas
where the disease is less severe; none
have died"
Cost to Public Nominal
Despite the difficulty and expense
of preparing the vaccine for use in