TYPHOID FEVEE IN DISTEICT OF COLUMBIA. 
55 
of the factors learned of which may have applied to the given case 
and then attributed the infection to the factor which seemed most 
probably applicable. 
In 45 houses more than one case occurred within a period of three 
months, and in these 45 houses there were, all told, 103 cases. Of 
these, 35 were attributed to milk infection, 28 to infection by con- 
tact, direct and indirect, and 40 to factors undetermined. The largest 
number which occurred in one house was 6 ; all of these 6 cases were 
attributed to milk. In fact, the occurrence of several cases, especially 
among children, within a few days in the same house was often found 
to be a good indication of a milk outbreak, and it was through such 
an occurrence in an institution, tow'ard the latter part of our studies, 
that our attention was first attracted to the outbreak among the 
customers of milk dealer No. 4. 
Among the many kindly suggestions given us by those interested 
in the typhoid fever situation in the District of Columbia w^as one 
(from Mr. MTiipple) that possibly many of the cases among white 
persons in Washington were contracted from colored servants. This 
point was considered in connection with the 306 cases last studied. 
Of these cases, 237 were at homes at which there were no servants. 
Three were at homes where white servants were employed and 
resided ; 22 were at homes where colored servants were employed and 
resided; 1 was at a home where a white servant was employed, but 
who went to his own home at night ; 43 were at homes where colored 
servants were employed, but who went to their own homes at night. 
Two of the cases were in the persons of colored servants who resided 
at the homes where they were employed. In no instances were his- 
tories obtained of cases of typhoid fever existing among the persons 
in the homes of colored servants during the 3 or 4 weeks prior to 
the onset of the cases in the families of their white employers. The 
reluctance with which servants usually gave information regarding 
illness in their homes led us to believe that their statements should 
be accepted with considerable reservation. 
PROPHYLAXIS. 
Of the 866 cases, 374, or 43.18 per cent, were treated at hospitals. 
The time of admission to hospitals of cases which were considered as 
having contracted the infection in the District of Columbia was as 
follows : 
Cases. 
Within 5 days after onset of illness 190 
Within 10 days after onset of illness 69 
Within 15 days after onset of illness 18 
Within 20 days after onset of illness 4 
Within 25 days after onset of illness 4 
