6()8 TRANSMISSION OF YELLOW FEVER BY MOSQUITOES. 



Froui January 11 till January 31, a period of twenty days, " Building No. 1 " con- 

 tinued to be occupied by two other nonimmune Americans, who, like those who 

 preceded them, have slept every night in the beds formerly occupied l)y yellow-fever 

 patients and in the nightshirts used by these patients throughout the attack, without 

 change. In addition, during the last fourteen nights of their occupancy of this house 

 they have slept each night with their j)illows covered with towels that had been 

 thoroughly soiled with the blood drawn from both the general and capillary circula- 

 tion, on the fir.«t day of the disease, in the case of a well-marked attack of yellow 

 fever. Notwithstanding this trying ordeal, these men have continued to remain in 

 perfect health. 



The attempt which we have therefore made to infect "Building No. 1" and its 

 seven noninunune occupants, during a period of sixty-three days, has proved an 

 absolute failure. We think we can not do better here than to quote from the classic 

 work of La Roche.' This author says: "In relation to the yellow fever, we find so 

 many instances establishing the fact of the nontransmissibility of the disease through 

 the agency of articles of the kind mentioned, and of merchandise generally, that we 

 can not but discredit the accounts of a contrary character assigned in medical writ- 

 ings, and still more to those presented on the strength of popular report solely. For 

 if, in a large number of well-authenticated cases, such articles have been handled 

 and used with perfect impunity — and that, too, often under circumstances best cal- 

 culated to insure the effect in (pie.stion — we have every reas(m to conclude that a 

 contrary result will not be obtained in other instances of a similar kind; and that 

 conseciuentiy the effect said to have been i)roduced by exjiosure to those articles 

 must, unless established beyond the jiossibility of doubt, be referred to some other 

 agency." 



The question here naturally arises. How does a house become infected with yellow 

 fever? This we have atteuipte<l to solve by the erection at Camp Lazear of a se(;ond 

 hou.«e, known as " Building No. 2," or the "Infected Mosquito Building." This was 

 in all respects similar to "Building No. 1," except that the door and windows were 

 placed on opposite sides of the building so as to give through-and-through ventilation. 

 It was divided, also, by a wire-screen ]iartition, extending from floor to ceiling, into 

 two rooms, 12 by 14 feet and 8 by 14 feet resj)ectively. Whereas, all articles admitted 

 to "Building No. 1" had been soiled by contact with yellow-fever patients, all arti- 

 cles admitted to "Building No. 2" were first carefully disinfected by steam before 

 being placed therein. 



On Decemlier 21, 1900, at 11.45 a. m., tluTc were set free in the larger room of tiiis 

 l>uilding fifteen mos<|uitoes — ('. /(7.Nc/(f/((.s- — which had previously been contaminated 

 l>y biting yellow-fever patients, a.« follows: 1, a severe case, on the second day, 

 November 27, IHOO, twenty-four days; 3, a well-marked ca.><e, on the first day, Decem- 

 l)er 9, 1900, twelve days; 4, a mild case, on the first day, ])eceml)er 13, 1900, eight 

 days; 7, a well-marked cuse, on the first day, December 16, 1900, five days — total, 15. 



Only one of these insects was considered capable of conveying the infection, viz, 

 the mosquito that had bitten a severe case twenty-four days before; while three 

 others — the twelve-day insect.^ — had })ossibly reached the dangerous stage, as they 

 liad been kept at an average temperature of <S2° F. 



At 12 noon of the same day John J. Moran — already referred to as case 2 in this 

 report — a nonimmune American, entered the room where the mosquitoes had been 

 freed, and remained thirty minutes. During this time he was bitten about the face 

 and hands by several insects. At 4.30 p. m. the same day he again entered and 

 remained twenty minutes, and was again bitten. The following day at 4.30 p. m. 

 he, for the third time, entered the room, and was again bitten. 



('((>ie 7. — On December 25, 1900, at 6 a. m., the fourth day, Moran complained of 

 slight dizziness and frontal headache. At 11 a. m. he went to bed, complaining of 



*R. La Roche: Yellow fever, vol. ii, p. 516, Philadelphia, 



