The leader., 1905-08-12
MOSQUITO THEORY PROVED
BEYOND SHADOW OF DOUBT
fIany Experiments by the Government Show
That Yellow Fever Can Be Transmitted
Only by the Mosquito

we give DetOW the details OF the
famous investigation made in Havana
in 1900 and 1901 by the American Mill
itary Commission, composed of Ma
jor w. Reed, M. D., and Drs J. Car
roll, A. Argamonte and !. W. Lazear,
which established the mosquito the
ory Of the origin of yellow fever be-
yond all question and paved the way
to the emancipation of Havana from a
disease which had prevailed there for
century and a half. In these exper-
lments Major Reed, with other Off
GERS and privates of the United States
army, risked their lives in the demon
stration. Assistant Surgeon Lazear
lost his life in the attempt. Major
Reed succumbed three years ago to
an attack of appendicitis in the city of
Washington.
The great work in Cuba, in demon
strating that yellow fever is transmit
ted by the mosquito, is thus briefly
described in memoir published last
year by the Walter Reed Memorial
Association at Washington:
The Study of Yellow Fever.
In June, 1900, Major Reed was sent
to Cuba as president of board to
study the infectious diseases of the
country, but more especially yellow
fever. Associated with him were Act
ing Assistant Surgeons James Carroll,
Jesse w. LaZear and A.. Argamonte.
At this time the American authorities
in Cuba had for a year and half en-
deavored to diminish the disease and
mortality of the Cuban towns by gen.
eral sanitary work, but while the
| health of the population showed dis
tinct improvement and the mortality
had greatly diminished, yellow fever
apparently had been entirely unaffect-
ed by these measures. In fact, owing
| to the large number of nonimmune
| foreigners, the disease was more fre-
auent than usual in Havana and in
| Quemados, near the camp of American
troops, and many valuable lives of
American officers and soldiers had
been lost Reed was convinced from
the first that general sanitary meas.
ures a'one would not check the dis
ease, but that its transmission was
partly due to an insect.
Cause of Yellow Fever.
To Reeds mind this indicated that
| the unknown infective agent has to
undergo a period of incubation of from
| ten to fifteen days and probably in the
body of the biting insect.
| Up to this time the most generally
accepted theory as to the causation of
| yellow fever was that of Sanarelli,
who claimed that the bacillus icete-
roids discovered by him was the spe-
cific agent of the disease. MajA'
Reed, in association with DR.. Carroll,
had, however, already demonstrated
that this bacillus was one widely dis
seminated in the United States and
bore no such relation to yellow fever.
In June, July and August, 1900, fhe
commission gave their entire atten-
tion to the meteorological study of the
blood of yellow fever patients and the
| post mortem examination of the or
gans of those dying of the disease.
| In twenty-four cases where the blood
was repeatedly examined, as well as
in eleven carefully studied autopsies,
| bacillus iceteroids were not discov-
cred, nor was there any indication of
the presence in the blood of a specific
cause of the disease.
| Application was made to Gen. Leon
ard Wood, the military governor of
Cuba, for permission to conduct ex-
periments on nonimmune persons, and
| a liberal sum of money requested for
| the purpose of rew4rding volunteers
who would submit themselves to ex-
periments.
1t was indeed fortunate that the mil
itary governor of Cuba was a man
who, by his breadth of mind and spe-
cial scientific training, could readily
appreciate the arguments of Major
| Reed as to the value of the proposed
work.
Money and full authority to proceed
were promptly granted, and to the ev-
erlasting glory of the American sol
der volunteers from the army offered
| themselves for experiment in plenty
and with the utmost fearlessness.
Death of Or. Lazear.
| Before the arrangements were en-
| tirely completed DR.. Carroll, a mem
Der of the commission. allowed him
self to be bitten by mosquito that
twelve days previously had filed it.
self with the blood of yellow fever
patient He suffered from a very Sc
we're attack. and his was the first ex-
perimental case. DR.. Lazear also ex-
/ perimented on himself at the same
4 time, but was not infected Some
days later, while in the yellow fever
ward, he was bitten by a mosquito
4 and noted the fact carefully. He ac-
| quired the disease in its most terrible
| form and died martyr to science and
a true hero.
No other fatality occurred among
| the brave men who in the course of
| the experiments willingly exposed
! themselves to the infection of the
dreaded disease.
The Camp.
/ A camp was especially constructed
| for the experiments, about four miles
lfrom Havana, christened Camp La
zear in honor of the dead comrade
1 The inmates of the camp were put in
| to most rigid quarantine and ample
time was allowed to eliminate any
possibility of the disease being
brought in from Havana.
The personnel consisted of three
nurses and nine nonimmunes, all in
the military service, and included two
| physicians.
From time to time Spanish immi-
grants, newly arrived, we're brought
son not known to be Immune was not
i dllUWSug w lSdFC Nc1ll4 pss VI IL u6 ulu
was forbidden to return
The most complete record was kept
i of the health of every man to be ex-
perimented upon, thus eliminating the
possibility of any other disease than
/ yellow fever complicating the case.
How the Experiments Were Made.
The mosquitoes used were especial
ly bred from the eggs and kept in a
building screened by wire-netting.
When an insect was wanted for an ex-
pertinent 1t was taken into a yellow
fever hospital and allowed to fill it,
self with the blood of patient; after
ward, at varying intervals from the
time Of this meal of blood, 1t was pur-
posely applied to nonimmunes in
camp.
In December five cases of the dis
ease were developed as the result of
such applications, IN January three