107 
the hands of persons, flies, and barely possibly from contamination 
of the water supply used for washing the milk cans. 
Neither dairymen No. 59 nor No. 11 mixed the milk from the various 
farms supplying them before bottling and delivering it to their cus- 
tomers. Had they followed this custom, which is rather general at 
the other dairies in Washington, there might have been a much 
larger number of cases in this outbreak. They both bottled directly 
from the cans as the cans came from the different farms. 
Dairyman No. 11 stated that he was quite sure that all the milk 
which he received from Mrs. X he sold to a bakery, where it was 
cooked. However, in view of all the evidence, it seems probable 
that he was mistaken and that some of the milk from the farm of 
Mrs. X was bottled at his dair}^ and delivered to his retail customers. 
As he acknowledged that he used the same scorning cloths and 
brushes on the milk cans w^hich had contained the milk from the 
farm of ^Irs. X, and on those in which the milk he bottled and retailed 
was stored, it is possible that the infection was so transferred from 
the cans of Mrs. X to the other cans. 
The positive finding of typhoid bacilli in the feces of Airs. X was 
determined on October 16, and on that date the sale of milk from 
her farm was discontinued by order of the health officer. Eight days 
later — October 24 — the last cases occmring among the customers of 
dairymen Nos. 59 and 11 had their definite onset of t}q)hoid fever. 
In each of the three years in which we have studied the typhoid- 
fever situation in Washington one or more pronounced and easily 
recognized milk outbreaks have occurred. The number of cases 
definitely traced to milk infection has amounted to about 10 per 
cent of the cases originating in the District of Columbia diuing the 
periods (Alay 1 to November 1) of all tlu*ee years. 
Besides the cases occurring in the course of the pronounced out- 
breaks there were very probably scattering cases due to infected milk 
which could not be traced. This surmise is supported by the fact 
that, coincident with the periods of these milk outbreaks, there have 
been increases in the number of cases not definitely attributable to 
any of the known factors. (See Chart No. 2.) 
A pernicious custom among the milk dealers of Washington is the 
exchange and use of unsterilized milk bottles. Bottles used for 
serving milk by a certain dealer on one day may be used by other 
dealers on the next day. Only two or three of the milk dealers make 
any pretense of sterilizing the bottles after collecting them from the 
various households and before refilling them with milk. It is readily 
conceivable, therefore, how bottles which have contained the infected 
milk of a certain dairy may carry infection to milk supplied by other 
dairies and so be responsible for scattering cases of typhoid fever 
among persons receiving milk from these other dairies. 
