Fleas and Plague 143 



During this time new centers of infection were 

 established, and since then it has been carried by 

 the commerce of the nations to all parts of the 

 world. It is not restricted, as many other epidemic 

 diseases, to the tropics or semi-tropics, although as 

 a matter of fact we find it is more prevalent in these 

 regions on account of the sanitary conditions. 



HOW PLAGUE WAS CONTROLLED IN SAN 

 FRANCISCO 



Attention is called to these things in order that 

 we may compare past conditions with present. 

 During the last few years San Francisco has been 

 fighting an outbreak of plague that in other days 

 would have been nothing less than a national 

 calamity. But with modern methods of handling 

 it, based on knowing what it is, what causes it and 

 how it is spread, the authorities there have been 

 able not only to hold the disease in check, but 

 practically to stamp it out with the loss of com- 

 paratively few lives. 



Dr. Blue of the Public Health and Marine Hos- 

 pital Service and his co-workers directed their 

 whole energy toward controlling the rats. A small 

 army of men were employed, catching rats in 

 every quarter of the city. Dr. Rucker reports that 

 fully a million rats were slain in this campaign. 



