CHAPTER X 



QUARANTINE IN THE CONTROL OF INFECTIOUS 

 DISEASES 



Quarantine, or isolation, as a method of controlling the 

 spread of infectious diseases dates from the efforts made by 

 Venice in 1403 to check the spread of the dreaded ^ 'Black 

 Death." All passengers arriving on ships at the port of 

 Venice were isolated in a special hospital situated on a 

 small island adjoining the city. Here they were kept for 

 forty days before being allowed to enter the city. This, 

 then, is the origin of the term "quarantine,'' quadrayinta 

 meaning forty. With increasing knowledge of the trans- 

 mission of infectious diseases there has come a change in 

 our methods of dealing with the spread of these diseases, 

 and this has markedly affected the duration of the period 

 of isolation enforced by health authorities. 



To a large extent the minimum period of enforced 

 isolation has been arrived at as the result of bacteriologic 

 investigations and animal experimentation. In addition 

 to this we are guided by disappearance of fever, freedom 

 from crusts or scabs, and the absence of catarrhal or sup- 

 purative processes. 



The period of isolation required in different diseases 

 varies considerably in different cities. In describing con- 

 ditions as they prevail in New York City at the present 

 time, therefore, we aim merely to give the student a 

 general idea of the considerations which guide health 

 officials in their action. 



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