THE TRANSMISSION OF INFECTIOUS DISEASES 57 



persons rather than by things — by contact with others, 

 by certain discharges of those who are infected, and by 

 insects and vermin. 



Terminal Fumigation 



The question Avhich at once arises is as to the need of 

 terminal room fumigation in infectious diseases. If such 

 diseases are not carried by fomites, why go to all the 

 trouble of room fumigation? As a matter of fact, a num- 

 ber of progressive health departments have discontinued 

 most of the terminal fumigations formerly done after con- 

 tagious diseases. Among these may be mentioned the 

 health departments of Providence, New York City, Bos- 

 ton, and INIilwaukee. In New York a very interesting 

 experiment was conducted in 1914 and 1915, fumigation 

 being discontinued in some of the boroughs and continued 

 in the others. No increase in the prevalence of the con- 

 tagious disease followed the discontinuance of terminal 

 fumigation. It should be understood, however, that in 

 discontinuing fumigation, increased stress is laid on other 

 and more efficient methods of disinfection, namely, 

 thorough cleaning, fresh air and sunlight, and particularly 

 renovation (i. e., repainting and repapering) when neces- 

 sary. IMoreover, the reader must bear in mind that fumi- 

 gation is still necessary in such diseases as typhus (to kill 

 vermin), yellow fever (to kill mosquitoes), and plague 

 (to kill rats). 



Insects as Carriers of Infectious Diseases 



Before leaving this subject, it will be well to devote a 

 little attention to the role played by insects and vermin 

 in the transmission of infectious diseases. This r6le may 



