Evening star., 1925-11-15
SPOTTED FEVER VACCINE
BY FREDERIC J. HASKIN.

Therapcutical circles are attaching
no small amount of Importance to
brochure on spotted fever vaccine re-
Gently published by the United States
Public Health Service. This work
prepared by r. X. Spencer and r. r.
Parker. surgeon and special expert,
respectively, OF the service. holds
promise of important results in the
immunizing of persons against this
disease which hitherto has been fatal
to most of its victims.
Spotted fever is peculiar to one
section only. 1t occurs nowhere but
in the Northwestern States. Idaho
and Montana are it's principal foci, al
though cases have been found In other
Northwestern States. In Montana
and Idaho ii is found in two or three
zones. the chief one being the Bitter
root Valley In Montana. In these
zones death rates vary, peculiar
phenomenon which shows that the
disease Is not constant in its actions.
II may be that 1t is susceptible to
different climates. In Bitterroot Val
ley 80 per cent of the cases are fatal.
Ticks Carry Disease Germs.
The disease is carried by ticks
which live on large and small animals.
including domestic beasts. 1t appears
only in Spring and Summer, at which
times ticks abound. 1t is not fatal
to animals, laboratory animals being
the sole exception. 1t Is not contagious
in the sense that one person may
convey it to another, the presence Of
the tick being necessary for contrac-
ton.
1t is less fatal in children, some
thing that has not been explained
There is no specific In curing 1t. Most
! of the cases that have recovered have
| been persons who developed a natural
immunity to it.
1t begins with a fever. Following
the inception a rash appears on the
second or third day. This rash breaks
| out all over the body. The patient.
| unless he develops the immunity
spoken of. usually dies some time be-
tween the fifth and tenth days. These
facts, and the character of the disease
appeared in medical annals some 40
years ago, but prior to the findings of
| Spencer and Parker there was nothing
Of note discovered in it's treatment or
prevention.
Three men, DIR. T. b. McClintoc
and two laboratory assistants of the
| Public Health Service, have died in
the work of investigation. These
! men were working in the laboratory
| maintained by the service at Hamil
| ton, Mont, when they were stricken.
DIR. McClintoc, desiring to be brought
| East again, was taken as far as Chi
| cago. where he died. No one In his
| company caught the disease. further
proof that 1t is not contagious.
Tourists May Be Endangered.
| With the construction Of road.
| through the zones in which spotted
| fever occurs, the danger of additional
| exposures arises. These roads Gu,
| across the tick infested territory and
! tourists will be threatened. Hence
| the work of Spencer and Parker IS
hailed by medical men. Through the
| use of the vaccine the disease may
| be controlled or prevented. At least
! there is hope of this being brought
about.
These men have shown that guinea
pigs could be inmunized against
spotted fever. Their recent expert
| ments show that this vaccine also
! will protect monkeys and that it
will confer immunity upon man.
Ticks. especially prepared, are per-
mitted to feed on guinea pigs for three
days, and then eviscerated, one by
| one, and ground in a mortar for 10 or
! Is minutes with sterile sand and q few
CUBIC CenIlInetefS OF salt solution, In
this manner the desirable substan noes
are obtained, the other fragments set.
tling to the bottom. and fairly homo.
geneous emulsion is the result. The
minimal infectious dose for guinea
pigs is determined by the injection of
graded dilutions, using 10 guinea pigs
for the test. If any of the guinea pigs
receiving one-thousandth Of tick fails
to develop spotted fever, the material
is not considered suitable. The ma.
| terial then Is run through other proc.
esses and is shown to have protective
qualities. 1t Is then re-emulsifled and
injected into guinea pigs.
In Investigations of Rocky Noun
| tain spotted fever, or other disease
transmitted by insect vectors, no at.
| tempt hitherto has been made. as far
as is known, to protect man by vacci-
nation. Thirty-four people, chiefly
laboratory and field workers in Rocky
| Mountain spotted fever, and others
whose occupations expose them to in.
| fection. have now been vaccinated.
Each lot of vaccine was first tested for
sterility and protective qualities by In.
lection into guinea pigs.
! The vaccine was administered sub