666 TRANSMISSION OF YELLOW FEVER BY MOSQUITOES. 



without effect, and Doctor Reed supposes that this individual '"■proba- 

 bly possesses a natural immunity from yellow fever." Doctor Reed 

 saj^s, with reference to these experiments: 



It is important to note that in the three cases in which the injection of the blood 

 brought about an attack of yellow fever, careful cultures from the same blood, taken 

 immediately after injection, failed to show the presence of Sanarelli's bacillus. 



Having- demonstrated the fact that j^ellow fever is propagated by 

 mosquitoes, Doctor Reed and his associates have endeavored to ascer- 

 tain whether it may also be propagated, as has been conmionly sup- 

 posed, by clothing-, bedding, and other articles which have been in use 

 by those sick with this disease. With reference to the experiments 

 made for the solution of this question, 1 can not do better than to 

 quote in extenso from Doctor Reed's paper read at the Pan-American 

 Medical Congress in Havana. He says: 



We believe that the general consensus of opinion, both of the medical profession 

 and of the laity, is strongly in favor of the conveyance of yellow fever by fomites. 

 The origin of epidemics, devastating in their course, has been frequently attributed 

 to the unpacking of trunks and boxes that contained supposedly infected clothing; 

 and hence the efforts of health authorities, both State and national, are being con- 

 stantly directed to the thorough disinfection of all clothing and bedding shipped 

 from ports where yellow fever prevails. To such extremes have efforts at disinfec- 

 tion been carried in order to prevent the importation of the disease into the United 

 States that during the epidemic season all articles of personal apparel and bedding 

 have been subjected to disinfection, sometimes both at the port of departure and at 

 the port of arrival, and this has been done whether the articles have previously been 

 contaminated by contact with yellow fever patients or not.- The mere fact that the 

 individual has resided even for a day in a city where yellow fever is present has been 

 sufficient cause to subject his baggage to rigid disinfection by the sanitary authorities. 



To determine, therefore, whether clothing and bedding which have been contami- 

 nated by contact with yellow fever patients and their discharges can convey this 

 disease is a matter of the utmost importance. Although the literature contains 

 many references to the failure of such contaminated articles to cause the disease, we 

 have considered it advisable to test by actual experiment on nonimmune human 

 beings the theory of the conveyance of yellow fever Ijy fomites, since we know of 

 no other waj' in which this question can ever be finally determined. 



For this purpose there was erected at Camp Lazear a small frame house consisting 

 of one room 14 by 20 feet and known as " Building No. 1," or the " Infected cloth- 

 ing and bedding building." The cubic capacity of this house was 2,800 feet. It 

 was tightly ceiled within with "tongue and-grooved" boards and was well battened 

 on the outside. It faced to the south and was provided with two small windows, 

 each 26 by .34 inches in size. These windows were both placed on the south side of 

 the building, the purpose })eing to prevent, as much as possible, any thorough circu- 

 lation of the air within the house. They were closed by permanent wire screens of 

 0.5 mm. mesh. In addition sliding glass sash were provided within and heavy 

 wooden shutters without; the latter intended to prevent the entrance of sunlight 

 mto the building, as it was not deemed desirable that the disinfecting qualities of 

 sunlight, direct or diffused, should at any time be exerted on the articles of clothing 

 contained within this room. Entrance was effected through a small vestibule, 3 by 

 5 feet, also placed on the southern side of the house. This vestibule was protected 

 without by a solid door and was divided in its middle by a wire-screen door, swung on 

 spring hinges. The inner entrance was also closed by a second wire-screen door. In 



