22 MARKET DAIRYING 



be offered for sale except that produced from cows that 

 have been shown to be free from tuberculosis by the 

 tuberculin test. 



A common means of infecting milk is through the water 

 used in the dairy. Many typhoid fever epidemics have 

 been positively traced to milk infected with typhoid or- 

 ganisms through the water supply. The purity of the 

 water used in a dairy should be absolutely above sus- 

 picion. 



Another means of spreading, disease through milk is 

 the milk bottle. Every dairyman will, at some time, have 

 customers in whose families there is sickness, and bottles 

 passing unsterilized from such homes to healthy ones, 

 are often the means of communicating the disease to the 

 latter. Many instances of this kind are on record. The 

 absolute necessity of sterilizing the milk bottles to pre- 

 vent the spread of contagious diseases is too evident 

 to require further discussion. 



Milkers and attendants who come in contact with per- 

 sons suffering from contagious diseases, or who may 

 themselves be afflicted with disease, should be rigidly 

 excluded from the dairy. Over five hundred epidemics 

 of various diseases, such as scarlet fever, diphtheria, 

 typhoid fever, etc., have been directly traced to infected 

 milk. 



With the large number of bacteria ordinarily found in 

 milk and with the great variety of pathogenic organisms 

 that are often disseminated by means of it, it behooves 

 us to know under what conditions milk should be pro- 

 duced and handled to reduce bacterial contamination to 

 a minimum. These conditions will be discussed in the 

 following chapter. 



