282 



YELLOW FEVER 



these, the majority gave a negative result, and 

 were found susceptible to infection, at a later 

 date, from the blood of a yellow-fever patient. 

 Two gave a positive result. In the course of these 

 experiments, Dr Lazear, a member of the Commis- 

 sion, died of the disease. In February 1901, and 

 again in July, the Commission published further 

 reports, emphasising the fact that the mosquito 

 conveys the disease, and denying that the disease 

 can be conveyed in clothing, bedding, and so 

 forth : — 



"Our observations appear to demonstrate that 

 the parasite of this disease must undergo a definite 

 cycle of development in the body of the mosquito 

 before the latter is capable of conveying infection. 

 This period would seem to be not less than twelve 

 days. 



"We also consider the question of house infec- 

 tion, and are able to show that this infection is 

 due to the presence of mosquitoes that have previ- 

 ously bitten yellow-fever patients ; and that the 

 danger of contracting the disease may be avoided in 

 the case of non-immune individuals who sleep in this 

 building, by the use of a wire screen. 



" We also demonstrate, by observations made at 

 this camp (Fort Lazear), that clothes and bedding 

 contaminated by contact with yellow-fever cases, 

 or by the excreta of these cases, is absolutely with- 

 out effect in conveying the disease." 



In February 1901, Dr H. E. Durham published 

 an abstract of an interim report of the Liverpool 

 School Yellow Fever Commission. He and Dr 



