CHAPTER I 



GENERAL REMARKS UPON INFECTION 



J\ A UCH confusion exists in the popular use of the 

 * " term " infection." By many it is supposed to 

 be synonymous with contagion. But this is not in ac- 

 cordance with established usage among well-informed 

 physicians. It is a far more comprehensive term ; 

 for, while all contagious diseases are infectious, not 

 all infectious diseases are contagious. A contagious 

 disease is one which may be transmitted by personal 

 contact, as, for example, smallpox, measles, scarlet 

 fever. These diseases may also be communicated, 

 indirectly, through the medium of objects which have 

 been in contact with infected individuals, such as 

 clothing, bedding, etc. (" fomites "). While the con- 

 tagious diseases mentioned and others which are gen- 

 erally recognised as liable to be contracted by contact 

 with the sick are also infectious, there are numerous 

 diseases which are infectious but not contagious. As 

 examples of this class we may mention the malarial 



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