INFECTION. 275 



to pass through the stomach and to reach the intestinal tract, 

 where it finds a lodgement and develops. The bacillus usually 

 gains entrance into the body through the agency of food or 

 drink, or infection may occur by coming in contact with any 

 article which has become contaminated by the discharges of a 

 person sick with typhoid, such as clothing, bed-linen, or eat- 

 ing utensils. 



Epidemics of typhoid fever are usually due to contamination 

 of drinking-water or milk by the alvine discharges of typhoid 

 patients. The washing of milk-cans with water contaminated 

 with the excreta of typhoids or with the typhoid bacillus is 

 a common mode of infection. Several epidemics of unusual 

 severity have been recorded which had their origin in the 

 water used to wash milk-cans or to dilute milk. In such 

 epidemics the cases of typhoid are usually scattered or occur 

 in groups, distributed along the route of the milkman. 

 Garden vegetables which have been sprinkled with infected 

 water may also convey the disease ; they should never be 

 eaten uncooked. 



Insufficient disinfection or careless disposition of the feces 

 and urine of typhoids is the source of contamination of the 

 water-supply. If the excreta of every case of typhoid fever 

 were thoroughly disinfected before they are disposed of, the 

 disease could be stamped out. Infection of the water-supply 

 may occur in many ways. Occasionally it is extremely diffi- 

 cult to account for the occurrence of epidemics of typhoid 

 fever, but a diligent search will always result in locating 

 the source of the infection. It must be borne in mind that 

 when the excreta are thrown on the ground or into a privy 

 vault they invariably filter through the ground and in that 

 way may reach the water-supply. Of course, modern sani- 

 tation and efficient drainage have done much to eradicate 

 this evil, but in rural districts these do not obtain. A well 

 or rain-water barrel may be on a lower level than the privy 

 vault or sewer, or not far away from it, and the water- 

 supply be polluted in that way. Every case of typhoid fever 

 has its origin in a previous case, and it is important to find 

 the source of contamination to prevent an epidemic of the 

 disease. 



