PROOF OF MOSQUITO ROLE 243 
DEMONSTRATION BY THE UNITED STATES ARMY COMMISSION. 
In 1900 the facts were determined by scientific methods. An American 
army being at that time stationed in Cuba, a medical board was appointed by 
Surgeon-General Sternberg for the purpose of investigating the acute infectious 
diseases prevailing in the Island. The Board consisted of Walter Reed, James 
Carroll, Jesse W. Lazear and Aristides Agramonte. Dr. Reed was the chairman 
of the Board. In the course of the work yellow fever naturally received the main 
share of attention. The claims of Sanarelli’s Bacillus icteroides were disproved, 
and Reed and his associates began a careful and thoroughly scientific investi- 
gation of the possibilities of mosquito carriage of the disease. The experiments 
carried on by the Board were as perfect in their methods as it was possible for 
scientific acumen and hard common sense to make them. Every possible element 
of error seems to have been guarded against. The final and conclusive tests, 
made during the autumn of 1900, were conducted with a spirit of earnestness, 
self-sacrifice and enthusiasm, which affected every one connected with the work, 
even in the most subordinate positions, private soldiers not only offering them- 
selves for the presumably dangerous test, but insisting that they should be 
accepted as subjects for experimentation. Dr. Reed, the master spirit of the 
investigation, was, moreover, the man above all men for this work, no less in 
his ability to compel the greatest confidence and enthusiasm, than in the abso- 
lutely complete manner in which the experiments were conducted. While the 
work was going on, criticism was invited and urged from Havana physicians, 
from visiting surgeons, and from every one interested, but so perfect were the 
plans that it seems impossible that any criticism could have been made. 
An experimental sanitary station was established in the open, a mile from 
Quemados. Two houses were built, tightly constructed, with windows and doors 
protected by wire screens. In one of these houses soiled sheets, pillow-cases, and 
blankets were used as bedding, and this bedding was brought straight from the 
beds of patients sick with yellow fever at Havana. For sixty-three days these 
beds were occupied by members of the hospital corps for periods varying from 
twenty to twenty-one days. At the end of this occupation the men, who were all 
non-immunes, were taken to quarantine for five days and then released. Not one 
of them was taken ill. All were released in excellent health. This experiment 
is of the greatest importance, as it demonstrates that the disease is not conveyed 
by fomites. Hence the disinfection of clothing, bedding, or merchandise, 
formerly supposed to have been contaminated by contact with yellow-fever 
patients, is unnecessary ; the disinfection work, which has been carried to the 
extreme in cases of yellow-fever epidemics in our southern States, has been 
perfectly useless. 
In the other house, which was known as the “ infected mosquito building,” 
were no articles which had not been carefully disinfected. The house contained 
two rooms, and non-immunes were placed in both rooms. In one room, sepa- 
rated from the other by wire-screen partitions only, mosquitoes which had bitten 
yellow-fever patients were introduced. In the other room they were excluded. 
In the latter room the men remained in perfect health; in the mosquito room 
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