CHAPTER XXX. 
CONTROL OF CITY MILK SUPPLY. 
The need of safe-guarding the milk supply of towns 
and cities becomes evident when we consider the extent 
to which milk acts as a carrier of infectious diseases. 
During the past twenty years, more than one hundred 
and fifty epidemics of typhoid fever have been traced to 
milk infected with the typhoid bacillus. There are records 
of twenty-eight epidemics of diphtheria and eighty or 
more of scarlet fever. 
Besides these epidemics, it is difficult to estimate how 
many thousands of isolated cases of these and various 
other diseases have been caused by infected market milk. 
The prevalence of tuberculosis among dairy cattle, alone, 
calls for a rigid control of city milk supplies. As stated 
elsewhere in this chapter, a large percentage of 
market milk contains the tubercule organism, and that 
the bovine tubercle bacillus can and does produce tuber- 
culosis in man has been established beyond a doubt by 
the Royal Commission on Human and Animal Tuber- 
culosis and by other notable scientific bodies and individ- 
uals. 
In addition to the danger of infection with strictly 
pathogenic bacteria, milk produced and handled under 
uncleanly conditions contains organisms which, while 
not classed with the pathogenic kinds, are nevertheless 
the cause of a high mortality among children under 
two years of age. These organisms come from manure 
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