New-York tribune., 1916-07-14


t;cal d;stribution irrespective of the
types or severity Of cases OF infantiie
paralvsis. Whether the cases cor
respond with tke so-called abortiVe
forms of the disease in which DEFINITE
naralysis of the muscles does not oc-
chr at all, or is so slight and fleet
ing as often to escape detection'
whether they correspond with the
meningeal forms in which the symp'
toms resmble those of acute meningi-
lis. with which muscular paralysis may
or NAV not be associated; or whetnei
they consist Of the familiar paralyt,e
condition, the virus is present not only
within the nervous organs Dut aiso
upon the mucous mebranes OF the nose
throat and intestines.
Escape of the Virus from the Body.
Micro-organisms which convey dis
ease escape from the body Of an In
fected individual in a manner en-
abling them to enter and multiply
within fresh or uninfected individuals
in such a manner as to cause Iurthei
disease. The virus OF lntantile
paralysis is known to leave the IN
fected human body in the secretions
of the nose, throat and intestines. IL
also escapes from contaminated
healthy persons in the secretions OF
the nose and throat. Whether 1t ever
leaves the infected body In other
ways is unknown. At one time Ger.
tain experiments seemed to show tna'
biting insects, and particularly the
stable fly, might withdraw the VIRUS
from the blood of infected persons ana
inoculate it into the blood of healthy
! persons. But as the virus has never
been detected in the blood of human
beings and later experiments WIN inc
stable fly have not confirmed the
earlier ones, this means OF escape OF
the virus must be considered ooupt-
full. On the other hand, 1t has been
shown by experiments on animals SO
that the same facts should be regard
ed as applicable to human beings, that
the virus seeks to escape from the
body by way of the nose and throat,
not only when incubation takes place
through these membranes, but also
when the incubation is experimentaiiy
made into the abdominal cavity, the
blood or the brain itself. From TINS
il is concluded that the usual means:
of escape of the virus is by way OF
the ordinary secretions of the nose
and throat, and, after swallowing
these, with the discharges OF the IN
testines.
The virus enters the body, as a rule
mucous membrane of the nose and
throat. Having gained entrance to
those easily accessible parts of the
body, multiplication of the virus oc-
ours there. after which it penetrates
to the brain and spinal cord by way
of the lymphatic channels which con-
meet the upper nasal membrane with
the interior of the skull. Whether
the virus ever enters the body in any
other way is unknown. Certain expert
ments already alluded to make it pos
sible that it may be inoculated into
the blood by insects, and other expert
ments have shown that, under peculiar
and extraordinary conditions, it may
in monkeys enter through the intes-
tines. But, while the latter two modes
Of infection may operate sometimes,
observations upon human cases of in
fantile paralysis and upon animals all
indicate that the main avenue of en-
trance of the virus into the body is
by way of the upper respiratory mu-
cous membrane-that is, the men,
Drdne OF INe nose anu tliOdI.
Resistance of the Virus.
The physical properties of the virus
of infantile paralysis adapt it well for
conveyance to the nose and throat.
Being contained in their secretions, 1t
is readily distributed by coughing,
sneezing, kissing, and by means OF
fingers and articles contaminated with
these secretions, as we'll as with the
intestinal discharges. Moreover, as the
virus is thrown off from the body
mingled with the secretions, 1T with
stands for long time even the highest
summer temperatures, complete drying
and even the action of weak chemicals
such as glycerin and carboiic acid,
which destroy ordinary bacteria. Hence
mere drying of the secretions is no pro.
lection; on the contrary, as the dried
secretions may be converted into dust
which is breathed into the nose and
| throat, they become a potential source
OF infection. The survival Of the virus
in the secretions is favored by weak
! daylight and darkness, and hindered by
bright daylight and sunshine. 1t is
readily destroyed by exposure to sun
light.
Conveyance by Insects.
Since epidemics of infantile paraly
| sis always arise during the period o.
warm or summer weather, they have
been thought of as possibly being con
nected with or dependent on insect life
| The blood-sucking insects have espe
cially come under suspicion. Expert
ments have been made with biting flies
bed-bugs, mosquitoes and with lice
Neither mosquitoes nor lice seem able
to take the virus from the blood of in.
! fected monkeys or to retain 1t for 9
! time in living state. In one instance
bed-bugs have been made to take VI
the virus from the blood of monkeys
but they did not convey it by biting t.
healthy monkeys. Certain experiments
did indicate that the biting stable fly
could both withdraw the virus from the
blood of infected and reconvey it to the
blood Of healthy monkeys, which be-
i