41 
Among the well to do therefore it frequently happens that infectious 
milk finds more victims, while among the poor the children are the 
' ones most likely to suffer. 
(e) Age and sex . — Women and children are usually credited with 
I drinking more milk than men, and it is generally believed that a 
I greater incidence of the disease in them is a characteristic of milk- 
' borne outbreaks. 
BACILLUS CARRIERS. 
The term “ bacillus carrier ” is most commonly associated with 
carriers of typhoid or Klebs-Loffler bacilli, and is used to designate 
persons who discharge the former in their feces or urine, or both,. or 
harbor Klebs-Loffler bacilli in their nose or throat. They may be 
acute or chronic carriers depending on whether they carry the organ- 
isms for short or long periods of time. 
Diphtheria carriers may become such from having had an acute 
attack of the disease, or by associating with others having acute 
attacks, or with other bacillus carriers. Klebs-Loffler bacillus carriers 
have undoubtedly frequently infected milk, and thus produced epi- 
demics of milk diphtheria. This in all probability is more likely 
to happen when the carrier is a milker at a dairy farm. 
Typhoid carriers are of particular interest because it has been 
found that an appreciable number of typhoid convalescents® dis- 
charge typhoid bacilli in the urine or feces, or both, and that from 
2 to 4 per cent continue to do so and become chronic typhoid bacillus 
carriers, that some continue so for years and some during the re- 
mainder of their lives. It is now known that not only may convales- 
cents become carriers, but that nurses and those coming in contact 
with the sick or with other carriers may in turn become typhoid ba- 
cillus carriers for longer or shorter periods of time and that, at times, 
without themselves falling victims to the disease. 
Undoubtedly these bacillus carriers constitute one of the important 
factors in the spread of typhoid fever by milk. Individuals in the 
early stages of typhoid may be physically well enough to continue at 
work milking or handling milk; others with very mild attacks may 
not cease work at all. Both may be discharging typhoid bacilli in 
the excretions. On the other hand, the chronic typhoid bacillus car- 
riers may continue to discharge bacilli not only for weeks but for 
®W. T. Graham, C. L. Overlander, John E. Overlander, and M. A. Dailey 
found 23 per cent. (Boston Med. and Surg. Journ., Jan. 14, 1909.) Officers 
of the medical and sanitary departments of the Government of India at the 
Central Research Institute at Kasauli found 11.6 per cent. ( Scientific Memoirs, 
No. 32, “An enquiry on enteric fever in India,” p. 7.) 
