406 



SCIENCE. 



[N. S. Vol. XXIII. No. 585. 



under medical supervision, in order that 

 any cases occurring among them may be 

 protected at once from mosquitoes. This 

 will insure that no secondary cases shall be 

 produced by infection from them. They 

 urge the necessity for protecting patients 

 from mosquitoes during the first three or 

 four days of the fever, because it is only 

 during this period that the mosquito can 

 acquire the infection. They state em- 

 phatically that in combating an epidemic 

 all preventive measures should be directed 

 against this insect and its relation to the 

 patient. After proper protection of the 

 patient all suspected mosquitoes must be 

 destroyed, and efforts should then be made 

 to exterminate all StegomyicB present in 

 the locality, if possible. 



Under the efficient management of the 

 director of public health, Dr. Oswaldo Cruz, 

 who is himself an experienced scientist, 

 over $65,000 per month was expended in 

 Rio de Janeiro, from April to December, 

 1903, in the war against mosquitoes. Even 

 the main sewers were fumigated and 

 myriads of mosquitoes destroyed in them 

 l)y the use of sulphurous acid. A sani- 

 tary brigade was organized into sections 

 for operation in the different districts into 

 which the city was divided. The person- 

 nel of this brigade comprised about 2,000 

 men, including 80 physician's. Their duties 

 Were specifically defined as : 



(1) The isolation of yellow-fever patients and 

 their protection from mosquitoes, including the 

 necessary arrangement of the isolation rooms; (2) 

 the destruction of mosquitoes in the house and its 

 surroundings and the destruction also of their 

 breeding places; (3) the removal of the patient 

 in a screened conveyance from his home to the 

 hospital, if he desired it, or if it were impossible 

 to isolate him in the house and the public interest 

 demanded it. 



All suspicious cases were treated as 

 though they were cases of yellow fever and 

 half-way measures were not tolerated. 



A manifesto setting forth the relation of 



the mosquito to the disease and the neces- 

 sity for the measures instituted was pub- 

 lished on April 26, 1903, for the instruction 

 of the people, and I can not do better than 

 cite a few extracts from it to show the 

 positive conviction of those in authority, 

 who had already witnessed the confirma- 

 tory experimental work of the French and 

 Brazilian commissions. 



EXTRACTS FROM THE MANIFESTO.^ 



2. Yellow fever is not conveyed from person to 

 person, nor is it transmitted by means of soil, or 

 articles used during illness, the sole means of 

 transmission is by the mosquito, as has been fully 

 determined. 



3. Several days after biting a case of yellow 

 fever the mosquito acquires the power to trans- 

 mit the disease, and it preserves that power for 

 some time, two and one half months or more. The 

 domestic habits of the mosquito explain sufficiently 

 why yellow fever is a disease that establishes it- 

 self in houses and why it is contracted only in 

 cities. 



8. During epidemics, when the disease is at 

 hand, all healthy persons should have mosquito 

 nets upon their beds at night, and they should 

 take care not to be bitten by mosquitoes during 

 the day, because yellow fever mosquitoes bite also 

 in the daytime. 



The new harbor regulations for vessels 

 entering with yellow fever on board are in 

 part as follows:* 



(a) The sick are immediately removed and iso- 

 lated with mosquito netting. 



(6) The mosquitoes in the entire vessel are 

 killed systematically and their breeding places are 

 destroyed. 



(c) Passengers who intend to stay in the har- 

 bor receive a health certificate and are subjected 

 to medical supervision for twelve days.' 



' J. Dupuy, ' Epidemiologic de la Fievre Jaune,' 

 Revue d'Hygiene et de Pol. San., Paris, 1905, 

 XXVIII., 13-29. 



' Otto and Neumann. 



^ This is baaed on the prolonged periods of in- 

 cubation reported by Marchoux, Salimbeni and 

 Simond, and is unnecessary, because it has never 

 been shown conclusively that an incubation period 



