Evening star., 1953-12-18
Some Serious MuIudies
Found Closely Related
FiIterobIe Viruses Cuuse
Them, Foundation Reports
By Thomos R. Henry


Yellew fever. the various forms Of
encephalitis which occur all over the
world, dengue or break-bone fever and
probably several other serious maladies
are quite closely related.
All these diseases are caused by III
terable viruSeS, most minute forms OF
life. The virus causing one can, under
certain circumstances, be changed so
as to produce the same effects as an
other. Thus the virus of yellow fever
can readily be changed from an agent
that kills monkeys by damage to the
liver to one that is fatal. like the en-
cephalitiS cauSerS, because of infection
of the brain.
This far-reaching discovery of dis
ease relationship hitherto unsuspected
has just been announced by the Rookie
feller Foundation.
For some years study of viruses has
been one of the foundations major
projects. It has brought about the dis
covery Of a group of hitherto unknown
forms, isolated from animals in African
jungleS. which appeared quite similar
to the types known to cause fatal brain
lntlammationS. No human disease was
known to be caused by these viruses,
although it was found that they were
spreading. Some finally turned up in
South America.
Size Varies Considerably.
They are so small, as are all organ
iSmS OF this type, that they are invisible
under any microscope. The Rockefeller
scientists. however, by a newly devised
method of f1ltering, were able to de-
termine their size.
1t developed that there were giants
and dwarfs in this submicroscopic
realm of life. The midget of the lot,
one of the African pseudo-encephaliti
organisms, was 10 millimicrons in
diameter. or about a thirteenth Of a
millionth of an inch. The diameter
of the largest. 122 millimicrons, makes
almost the difference between a man
and an elephant.
From this came the discovery that
most OF the encephalitis group, the
yellow fever and the dengue viruSeS,
belonged among the dwarfs. This led
to the unexpected finding of a prob
able relationship.
"Of the methods available for claSSi-
fy!ng viruses," says the foundations
annual report, "the immunological ones
appear to have the most promise.
These rely on the fact that animals
which have been infected with a virus
develop antibodies which circulate in
the blood. These antibodies react spe-
officially with the agent causing the
Infection. A monkey is immunized
with given virus. After it has de-
veloped protective antibodies q sample
OF its blood. together with another
virus, is injected into mice II the
mice live, it means that one virus must
have stimulated the production of both
its specific antibodies and antibodieS
Tor the other virus. Therefore the two
vlruSes must have some antigenes in
common.
by this means the laboratory staff
have found large group of viruses all
immupologically related. The group
comprises well-known viruses such as
yellow fever, dengue, Russian spring.
summer encephalitis, japanese en-
cephalitis, ST. Louis encephalitis and
several of the newly discovered viruses."
Curious Relationship Found.
BY this method definite relation
and several kinds of encephalitis.
Dengue serum, as rule, gave clear-cut
protection against st. Louis encepha-
litis. Yellow fever serum gave complete
protection against one of the African
viruses of the encephalitis group. This,
in turn, gave some protection against
yellow fever.
"These findings" says the report,
definitely relate diseases like yellow
fever, which cause death by damage to
the liver. to diseases which cause death
by infection of the BRAIN
curious relationship was found be-
tween louping ill. serious malady of
sheep in Scotland, a form of human
encephalitis carried by a tick-born
virus in Siberia, and an encephalitis
transmitted by East African mosquitoes.