Evening star., 1932-10-06


was stricken with the disease in much
the same way, but has completely re-
covered
The mortality of endemic typhus is
low At first it was feared that DR..
Dyer had contracted either infantile
paralysis or the even more dreaded
pSittacosis or parrot fever. since he had
come in contact with both organisms
recently. Dread of a renewed outbreak
of parrot fever among the laboratory
workers was especially great since this
disease assumed such serious proper
tions two Winters ago that it forced the
temporary closing of the laboratory.
Fairly Well Established.
Today, it was stated at the Public
Health Service, the diagnosis of endemic
typhus seems to be fairly well estab-
lished. The actual nature Of this dis
ease was first established by DR.. Dyer's
own experiments three years ago. The
European form of typhus, it is well
known, is spread by human lice and
throughout history has been terrible
scourge where men are congested IN
great numbers and under inSanitary
conditions-as in army camps or prls-
OnS
But when DR.. Dyer examined the rec
ords of American cases they oio not
seem to fit into this picture. They were
especially prevalent in the Central At
lantic States, appeared chiefly in
homes which, examination showed,
were exceptionally clean and where
no body lice could be found. and
resulted in lower mortality. DR..
Dyer finally demonstrated that this was
a slightly different disease, which was
spread by rat f1eas Rats captured IN
a Baltimore warehouse near which sew
eral cases had been reported yleldeo
feas with which it was possible to in
noculate guinea pigs and thus establish
strains of the deadly filterable virus.
Constant Flea Supply.
In order to continue the experiments
it was necessary to keep constant sup
ply of the fleas Various technical dill
ficulties arose in this work and Dr.
Over finally solved the problem, without
mentioning it to any of his associates, by
raising them in containers strapped 10
his own body so that they could feed on
his blood The first known about it was
one evening when he attended a social
function at the home of fellow medical
officer of the Public Health Service.
Throughout the evening" it was
noted. the doctor appeared very uncom-
Portable and was not joining in the
spirit of the occasion. His host Sus-
pected that he was sick and asked him
about it.
Its nothing" DR. Dyer IS quoted as
saying. I've got fleas and they're bit
ing particularly bad tonight"
Although he had established beyond
dispute that the disease could be given
to guinea pigs by the bites Of infected
rat fleas the experiment was not abso-
lutely perfect until the virus actually
could be demonstrated to have been
transmitted to a human being by flea
bite. This is now the case.
Vaccine Next Step.
After establishing the source Of the
disease, the next step was to produce
vaccine by which persons in an infected
territory could be protected. Endemic
typhus tends to have spotty distribu-
tion. DR.. Dyer sought to make vac
cine from the ground-up bodies of in
fected fieas, following the procedure
followed in making the highly success
full spotted fever vaccine by the Ma
tional Institute of Health.
Early this Summer, it was announced.
a vaccine had been made which met
with some success when used with
guinea pigs There was still long way
to go before it was perfected to a de-
gree which would make it safe to use
on human beings.