THE INFECTED STEGOMYIA 137 



tion to rid yellow fever countries of a pest wliicli 

 causes so much suffering and cripples commerce. 



THE INFECTP:I) STEGOMYIA CALOPUS 



A knowledge of tlie following facts is necessary 

 to understand the application of the prophylactic 

 measures which are now employed. The yellow fever 

 patient is only capable of infecting the stegomyia 

 during tlie first few days of the onset of the disease ; 

 the period usually given is the first three days, although 

 the French authorities extend the infective period. 

 The yellow fever cadaver after the first three days 

 of illness is non-infectious ; in consequence the 

 separate burial ground for yellow fever cases is need- 

 lessly harsh, quite unnecessary, and unscientific. At 

 710 late stage can the yclloiv fever patient or tlie 

 cadaver infect man directhj. In common with many 

 other non-immuncs I was almost daily in the Yellow 

 Fever Emergency Hospital examining patients and 

 assisting at post-mortems, but no case of infection ever 

 occurred amongst us. The well-screened Emergency 

 •Hospital, although crowded with patients and extremely 

 hot, was, nevertheless, one of the safest places in New 

 Orleans, because the stegomyia was effectively shut out. 

 No case of direct transmission from the patient to man 

 has ever been recorded. The only means is through 

 the mosquito, as Ross has proved in tlie case of malaria. 



When the stegomyia has taken a meal of blood 

 from a patient in the infective stage, it is not at 

 once capable of transmitting by its bite the virus to 

 a healthy individual. A very definite number of days 



