The Tupelo journal., 1905-08-11
MOSQUITO THEORY PROVED
BEYOND SHADOW OF DOUBT
r1any Experiments by the Government Show
That Yellow Fever Can Be Transmitted
only by the Mosquito.

Camp Lazear to a yellow fever hos
pital, one mile distant. Every person
in camp was rightly protected from
accidental mosquito bites, and not in
O single instance did yellow fever de-
velop In the camp except at the will
of the experimenters. The expert
ments were conducted at a season
when there was the least chance of
naturally acquiring the disease and
the mosquitoes used were kept active
by maintaining them at a summer
temperature. A completely mosquito
proof building was divided into two
compartments by a wire screen parti-
ton; infected insects were liberated
on one side only. A brave non-immuna
entered and remained long enough to
allow himself to be bitten several
times. He was attacked by yellow fe-
yer, while two susceptible men in the
other compartment did not acquire the
disease, although sleeping there thir-
teen nights. This demonstrates in
the simplest and most certain man
ner that the righteousness of the
building was due only to the presence
of the insects.
every attempt was made to infect
individuals by means of bedding,
clothes and other articles that had
been used and soiled by patients suf-
fering with virulent yellow fever.
A Convincing Report.
Naturally yellow fever is transmit
ted by the mosquito. The harmless
ness of fomites has been fully demon
tsrated by our experiments in 1900
and 1901, in which three young Ameri-
oa-- -1Art &c., voy 4o@,D4srn
nights in a room from which mosqui-
toes were excluded garnished with ar
ticles soiled with discharges from ia.
tai and other cases of yellow fever.
Three and four large boxes were
packed and unpacked each morning
by these nonimmunes, who suffered
no disturbance of health from these
exposures. The room was twenty
feet by fourteen feet, double walled,
tightly sealed, heated to above 80 de-
grees Fahrenheit and dark.
1.-TWO other nonimmunes then occu-
pied the room for twenty nights, while
additional articles of bedding and
clothing were added. They slept in
the garments and between the sheets
that had covered cases of yellow fe-
yer, some of which were fatal. The
result of the second attempt was nil.
A third attempt was then made with
two additional nonimmunes, equally
without success. Not the slightest in
disposition followed close and inti-
mate contact with this repulsive mate
rial in any case. Temperatures and
pulse rates were recorded at regular
and frequent intervals. Four of these
seven nOnimmunes were subsequently
infected by blood injections and by
means of infected mosquitoes.
Another kind of experiment was
included in the Cuban Investigations
of yellow fever. A room was pre-
pared so as to preclude the possibility
of infection by fomites (infected arti-
cles). Every article contained in the
room had been previously disinfected
Land was thoroughly clean. The only
possible mean of infection with yeE
low fever was by infected mosquitoes,
liberated in the room containing the
human subjects of the experiment.
Yellow fever promptly followed the
introduction of mosquitoes into the
room.
What Experiments Proved.
Besides the experimental cases
caused by mosquito bites. four non
immunes were infected by injecting
blood drawn directly from the veins
of yellow fever patients in the first
two days of the disease, thus demon
strating the presence of an infectious
agent in the blood at this carly period
of the attack.
Even the blood serum of a patient,
passed through a bacteria-proof filter,
was found to be capable of causing
| yellow fever in another person.
1.-THE details of the experiments are
most interesting, but it must here suf-
fee to briefly sum up the principal
conclusions of this admirable board
of investigators of which Reed was
the master mind:
81. The specific agent in the causa-
ton of yellow fever exists in the blood
of a patient for the first three days of
his attack, after which time he ceases
to be a menace to the health of 9TH
ers.
"2. A mosquito of a single species.
stegomyia ~faciata, ingesting the, blood
of the patient during this infective pc
riod is powerless to convey the disease
to another person by it's bite until
about twelve days nave elapsed, but
can do so thereafter for an indefinite
period, probably during the remainder
of it's life.
"3. The disease cannot be spread
in any other way than by the bite of
the previously infected stegomyia. Ar
ticles used or soiled by patients do not
carry infection.
these conclusions pointed so clear
ly to the practical method of extermi-
mating the disease that they were at
once accepted by the sanitary author
tiles in Cuba and put to the test in
Havana, where for nearly a century
and a half, by actual record, the dis
ease had never failed to appear an
nually.
Havana Free From Fever.
"In February, 1901, the chief SAM
tary officer In Havana, Major w. C.
Gorgas, Medical Department of the
United States Army, instituted meas
| ures to eradicate the disease, based
entirely on the conclusions of the COM
mission. Cases of yellow fever were
required to be reported as promptly as
possible, the patient was 1T first rigid
ly isolated, and Immediately upon the
report a force of men from the mill
tary department visited the house. All
! the rooms of the building and of the
n%eighboring houses were sealed and
fumigated to destroy the mosquitoes
present. Window and door screens
we're put up. and after the death or
recovery of the patient his room was
fumigated and every mosquito de-
stroyed. A war of determination was
also waged against mosquitoes in gen.
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