Typhoid Fever from Milk. i qi 



Since the acidity varies immediately after milking, after lac- 

 tation, among individuals, and even in milk from different teats, 

 and from interrupted milkings, the immediate measuring of the 

 degree of acidity constitutes no proof of the age of the milk. The 

 periodically continued titration of the same sample may, however, 

 be a good indication as to whether the milk has passed the incu- 

 bation phase and thereby afford an approximate indication of 

 the "age." By "age" is not understood the difference in time 

 between milking and examination, but a condition which may ap- 

 pear in milk sooner or later, depending on the cleanliness in its 

 preparation and handling, and on the outside temperature. This 

 condition is effectively determined by the reduction of methylene 

 blue. If the milk has once passed the incubation time the curve 

 of acidity rapidly and progressively rises, when the milk is kept 

 subsequently at temperatures at which lactic acid bacilli grow pro- 

 lifically (20 to 37 deg.). 



Koning made a test of milk which at delivery gave a degree 

 of acidity of 15.8 ( T V n Na OH :100), 



And showed after at 10 deg. 22 deg. 37 deg. C. 



1 day 16.4 28.8 96.0 



2 days 16.7 91.1 92.8 



3 days 17.2 102.4 105.2 



4 days 17.9 96.4 144.0 



5 days 26.2 105.6 184.0 



6 days 39.2 103.2 219.6 



7 days 57.6 102.8 241.6 



8 days 65.2 106.0 261.6 



Since, however, the amount of lactic acid formation does not 

 depend on the time and temperature alone, but also on the variety 

 of bacteria growing in the milk, only general conclusions as to 

 the aging of the milk can be drawn. 



Subsequent Contamination With Infections of Man. 



The occurrence of disease producing agents in milk is of 

 interest from the standpoint of tracing the origin of disease, 

 but from a milk inspection standpoint it is a most thankless field. 

 These disease producers may originate from affected persons, or 

 from healthy bacilli carriers, or they may reach the milk through 

 infected material, as, for instance, infected water used in washing 

 utensils, or as an adulterant, or in the treatment and preparation 

 of milk products. 



That milk may become a transmitter of disease has been posi- 

 tively proven. 



1. Typhoid Fever. The causative agent may contaminate 

 the milk through infected water, through vessels which were 

 returned without cleaning from houses harboring persons affected 

 with typhoid, through affected and convalescing patients who are 

 employed in producing or in the subsequent handling of milk, and 



