Yellow Fever and Other Diseases 107 



quitoes. Non-immunes with business in Rio make 

 it a habit to sleep at Petropolis, and thereby escape. 



The authorities at Rio are perfectly convinced of 

 the truth of the mosquito theory. Dr. Oswaldo Cruz, 

 Director of Public 

 Health, conducted a 

 most vigorous cam- 

 paign against the 

 insects in the year 

 1903, spending over 

 $65,000 per month 

 from April to De- 

 cember on the work 

 of the sanitary bri - 

 gade of about two 

 thousand men, which 

 thoroughly and sys- 

 tematically went over 

 the city, isolating and 

 screening patients, 

 destroying insects in 

 the infected houses, 

 wiping out breeding 

 places, moving pa- 

 tients to hospital, 

 and even fumigating 

 the main sewers. 



From vessels en- 

 tering the harbors 

 any patients are at 

 once removed and secluded, the vessel rid of mos- 

 quitoes and their breeding places, and all passengers 



Fig. 22. — Stegomyia calopus, female 

 (greatly enlarged). 



