14 YELLOW FEVER PROPHYLAXIS IN NEW ORLEANS 



The symptoms of disease will also not declare themselves in man 

 at once, for as just seen in the case of the mosquito, an incubation 

 period is also necessary in the case of man and the period is usually 

 five days. Consequently an interval of a little over two weeks 

 usually occurs before secondary cases manifest themselves in 

 fumigated houses. 



Difficulties of Combating the Disease in the Past. 



It can be readily understood from the preceding remarks how 

 hopeless and ineffective were the measures of prevention used in the 

 past, and that, too, in spite of the fact that in the more recent periods, 

 Listerian principles of disinfection were applied, carbolic acid and 

 perchloride of mercury being freely used as disinfectants. For 

 instance, although Major Gorgas had, previous to the advent of 

 Reed, Carroll, Agramonte and Lazear, made a vast change in the 

 sanitary condition of Havana, Yellow Fever was, nevertheless, not 

 affected, it only ceased after ejn-ploying methods directed against 

 the mosquito, viz. : fumigation and screening. In Belize, during 

 the recent (1905) epidemic, cases of Yellow Fever occurred amongst 

 the best cared-for class of people living in the best residential houses, 

 where the sanitary arrangements were excellent. 



In the past from want of knowledge of the true method of trans- 

 mission, rigorous house quarantine was enforced in the epidemic of 

 1878 in New Orleans, and vast quantities of disinfectants were used, 

 clothing and baggage was disinfected or destroyed, but nothing but 

 the frost — the natural means of preventing the activity and breeding 

 of the mosquito — stopped the fever. Ships have been turned away 

 with the dying on board or subjected for long periods to quarantine, 

 thousands of tons of harmless stone ballast have been thrown over- 

 board or disinfected, lest they should spread contagion. 



Prejudice against Excavating and -Dredging. 

 Excavations and dredgings from early periods have been regarded 

 with the greatest suspicion, and by a New Orleans Ordinance it is 

 forbidden to make excavations, clean out canals, or tear up the streets 

 from May 1st to September ist. This Act is a survival of the old 

 theory of miasmata, and it has led to the postponement of most 

 useful operations for the general good of the community. In his 



