Jesse William Lazear
(1866 - 1900)
rather think I am on the track of the real germ," Jesse W.
Lazear wrote his wife from Cuba on September 8, 1900. Seventeen days later, the fulminating
case of yellow fever Lazear had contracted just over a week after
writing Mabel H. Lazear suddenly ended the young scientist's life.
He was 34 years old. Unlike so many other yellow fever fatalities,
however, this one would lead to a direct and highly successful assault
on the disease itself. Yellow fever's ascendancy, endemic in Cuba,
was about to be undermined.
Lazear had reported
to Camp Columbia, Cuba in February 1900 for duty as an acting assistant
surgeon with the U. S. Army Corps stationed on the island. Here
he undertook bacteriological study of tropical diseases, particularly
malaria and yellow fever, and in May he was named to the Army board
charged with "pursuing scientific investigations with reference
to the infectious diseases prevalent on the island of Cuba."
placed him officially in the company of Walter
Reed, James Carroll, and Aristides Agramonte -- the U.S.
Army Yellow Fever Commission -- though Lazear had already met
Reed the preceding March on a project to evaluate the efficacy of
electrozone, a disinfectant made from seawater collected off the
Cuban coast. While Reed was in Cuba that March, Lazear discussed
with him the recent discovery of British scientist Sir Ronald Ross
concerning the mosquito vector for malaria. At Johns Hopkins Hospital
in Baltimore, where he was first a medical resident and later in
charge of the clinical laboratory, Lazear had followed Ross's accomplishments
with great interest, and pursued field work and experimentation
on the Anopheles mosquito with fellow Hopkins scientist William
S. Thayer. Lazear was thus the only member of the Commission who
had experience with mosquito work, and was consequently the most
open to the possible verity of Cuban scientist Carlos
Juan Finlay's theory of mosquito transmission for yellow fever.
record is apparently silent as to when Lazear first visited Finlay.
Certainly by late June Lazear was beginning to grow mosquito larvae
acquired from Finlay's laboratory, the first specimens brought to
him by Henry Rose Carter, of the United
States Public Health Service.
Not long after arriving in Cuba Lazear met Carter, whose own
observations on yellow fever strongly suggested an intermediate
host in the spread of the disease. However, Army Surgeon General
George Miller Sternberg, who organized the Yellow Fever Commission,
first charged the board members to investigate the relationship
of Bacillus icteroides to yellow fever -- proposed by the
Italian Scientist Giuseppe
Sanarelli as the actual cause of the disease. "Dr. Reed had
been in the old discussion over Sanarelli's bacillus and he still
works on that subject," Lazear wrote his wife in July, "I
am not all interested in it but want to do work which may lead to
the discovery of the real organism."
Soon he would have the opportunity. The relatively quick
failure of the Bacillus icteroides inquiry opened the door
to what became the ground-breaking mosquito work, and Lazear was
well placed to begin.
project started in earnest on August 1, 1900. In a small pocket
notebook Lazear noted the preparatory work of raising and infecting
mosquitoes, and subsequently recorded the series of eleven experimental
inoculations made from the 11th to the 31st of August, the last
two producing cases of full-blown yellow fever. These two positive
cases developed from mosquitoes allowed to ripen over a period of
12 days, and this was Lazear's crucial discovery. The epidemiological
pattern was thus entirely consistent with Carter's observations
of a delay between the primary and secondary outbreaks of yellow
fever in an epidemic, and, in addition, explained why Finlay's experiments
had been largely unsuccessful -- he had not waited long enough before
inoculating his subjects.
Lazear never directly admitted to experimenting on himself, when
Reed reviewed Lazear's sketchy notations he evidently found entries
strongly suggesting Lazear's case was
not accidental, as officially reported. Unfortunately, the little
notebook so crucial to the preparation of the Commission's famous
initial paper, "The Etiology of Yellow Fever -- A Preliminary
from Reed's Washington office after his own untimely death in 1902.
Still, Lazear's invaluable contribution to the Commission's victory
was widely recognized and elicited tributes from many quarters:
"He was a splendid, brave fellow," Reed said of his young
colleague, "& I lament his loss more than words can tell;
but his death was not in vain- His name will live in the history
of those who have benefited humanity."  "His death was a sacrifice to scientific research of the
highest character," stated General Leonard Wood, military Governor
of Cuba. "Your husband was a martyr in the noblest of causes,"
Dr. L. O. Howard wrote to Mabel Lazear, "& I am proud to
have known him. . . . His work contributed towards one of the greatest
discoveries of the century, the results of which will be of invaluable
benefit to mankind." And so they were. Though Lazear's one-year-old
son and newborn daughter never knew their father, they grew up in
a world liberated -- almost in its entirety -- from the disease
that killed him.
 Letter fragment from Jesse W. Lazear to Mabel Houston
Lazear, 8 September 1900, Philip S. Hench Walter Reed Yellow Fever
Collection, Claude Moore Health Sciences Library, Department of
Historical Collections and Services, accession number: 00344001.
 Military Orders for Walter Reed, James Carroll,
Aristides Agramonte, and Jesse W. Lazear, 24 May 1900, Hench
Reed Collection, accession number 02019001.
 "Conversation between Drs. Carter, Thayer,
and Parker," 1924, Henry Rose Carter Papers, Claude Moore
Health Sciences Library, Department of Historical Collections
and Services, Box 1.
 Letter fragment from Jesse W. Lazear to Mabel Houston
Lazear, 15 July 1900, Hench Reed Collection, accession number:
 Walter Reed, James Carroll, Aristides Agramonte,
Jesse W. Lazear, "The Etiology of Yellow Fever -- A Preliminary
Note," Proceedings of the Twenty-eighth Annual Meeting
of the American Public Health Association Indianapolis, Indiana,
22, 23, 24, 25, and 26 October 1900.
 Letter from Walter Reed to Emilie Lawrence Reed,
6 October 1900, Hench Reed Collection, accession number: 02135001.
 Letter from Leonard Wood to the Adjutant-General,
United States Army, November 1900, Hench Reed Collection, accession
 Letter from Leland Ossian Howard to Mabel Houston
Lazear, 7 February 1901, Hench Reed Collection, accession number: