View report page

39
It is of interest to note that experience in the vaccination of
the population against Cholera, Enteric Fever, Small-Pox, and
Plague, suggest that it is not necessary to completely immunise
each individual or all individuals to prevent spread. Thus the
attainment of the ideal may not be so difficult as was at one time
thought.
It will be noticed that nothing has been said relative to the
possibility that the cow through the various food products
obtained from that animal, may be the source of infection in man.
To put the matter briefly, it may be stated that the type of
parasite found in each is distinct, though each variety may
be found in either. Further, it is a fundamental principle of Isolation
Hospitals, and the handling of all infectious ailments, that if
an individual is attacked by any variety of a particular organism
he is immune to any further infections of all varieties of that
organism. This is not strictly true, but it is sufficiently so for
administrative purposes. Hence the segregation of all varieties of
Measles, Scarlet Fever, Diphtheria, etc., in one Ward. Now, if
the two commonest varieties of tubercle bacilli (there are many
others) compete for the occupation of a particular human being,
that derived from human source is, in the majority of cases, implanted
on the growing child before the bovine variety, and the
latter is probably prejudiced on that account alone; as a consequence
the number of cases which seem to be due to the bovine
variety are not so numerous as that derived from human sources.
In so far as all mixed milk, and much of the meat, can be regarded
as infected, and the cooking in many instances is not sufficient
to kill the organism, the dosage must be very massive, yet
it produces a relatively small effect.
The bovine variety is probably not an important factor
because the available field has been previously occupied by strains
of human origin. So long as human tuberculosis occupies the
position it does, bovine Tuberculosis must assume a subsidiary