44 
Kayser, in 1905, reported two small milk outbreaks of typhoid 
fever traced to chronic bacillus carriers as the source of infection.® 
SOURCE OF MILK CONTAMINATION. 
(1) From hands of milker . — Many dairy employees take no pre- 
cautions to keep the hands clean, and in fact the milker who washes 
his hands before milking is the exception and not the rule. He may 
be a typhoid bacillus carrier and be discharging typhoid bacilli in the 
excretions, and any carelessness in toilet is apt to deposit bacilli on 
the hands and under the finger nails. In the act of milking it is 
more than likely that he will wash at least some of them into the milk 
pail, and especially so if he resorts to a custom, all too common, 
of moistening his hands by squirting milk upon the palms pre- 
liminary to milking. 
The milker’s hands may have become soiled in acting as nurse 
for some case of typhoid in the family. He may be a convalescent 
from scarlet fever and be shedding particles of epidermis into the 
milk, or he may have diphtheria, or possibly tuberculosis, and with 
every act of sneezing and coughing spray tubercle or Klebs-Loffler 
bacilli with particles of sputum. If he does, as is not entirely un- 
known among careless milkers, and moistens his hands by spitting 
into the palms to facilitate the action of the fingers upon the teats, 
it is easily seen how infective material may find its way into the milk. 
(2) Air and dust of the stable . — The stable dust may contain 
organisms eliminated by those working in it, and as some of this 
dust and other stable refuse adhering to the flanks, buttocks, and 
udders of the cows and floating in the air finds its way into the milk, 
under the conditions sometimes employed, it may carry with it these 
organisms. 
(3) The milk pail . — The milk pail may have been washed and 
taken care of by some person or member of the family suffering from 
a contagious or infectious disease and in the handling have received 
its quota of typhoid or other bacilli which thus find their way into 
the milk. 
(4) Water supply.— T \\q water supply of the farm or dairy may 
be at fault. Farms are often very unfortunate in the location of their 
wells, which very frequently become polluted by cases of typhoid on 
the premises. The privy vaults are at times not far distant and are 
apt to be leaky and subject to seepage, and when a case of typhoid 
®A further discussion of the subject of bacillus carriers and epidemics due 
to them^will be found in the chapter on “ The milk supply of cities in relation 
to the epidemiology of typhoid fever.” 
