ASIATIC CHOLERA 



119 



which in some way has become infected and which 

 has not been sterilised by heat. The cholera spiril- 

 lum is so easily destroyed by heat that the prevention 

 of the disease is a comparatively simple matter. Any 

 article of food or drink which has been subjected for 

 a few minutes to a temperature of 140 Fahr. (60 

 C.) is absolutely safe, unless it has been reinfected 

 after such exposure. Such reinfection might occur if 

 the sterilised food or liquid is exposed to contamina- 

 tion by infected flies. These insects, without doubt, 

 not infrequently act as carriers of infection from ex- 

 posed cholera excreta on the ground or in shallow 

 pits to articles of food or drink which they light 

 upon or fall into. When the water supply of a town 

 becomes infected as a result of contamination by 

 cholera excreta, a general epidemic is almost sure to 

 occur, unless those using the water are sufficiently 

 intelligent and well informed to take the precaution 

 of sterilising, by heat, all water used for drinking 

 purposes. When this is done there is little liability 

 to infection through other channels, with the excep- 

 tion of the milk supply which should also be steril- 

 ised by heat and the danger from flies already 

 referred to. This latter source of infection is to be 

 guarded against by a strict sanitary police, by which 

 all exposed excreta are covered with earth or dis- 

 infected, and by the use of fly screens and other 



