View report page

102
long as fourteen days, but more commonly from
one to three days.
In the case of diphtheria, the frequent discovery
of the living bacillus diphtheria in the throats of
persons presenting no clinical symptoms of the disease,
greatly complicates the question of incubation. In
the absence of any systematic bacteriological examination
of the throats of the patients and the other
members of the household, it is impossible to eliminate
errors due to the conveyance of infection by
persons apparently quite well. As, however, a working
standard is requisite, a period not exceeding three
weeks will be taken as the incubation period of
diphtheria, and the possibility of conveyance of
infection by the method already alluded to set aside
for the present.
In connection with diphtheria and diphtheritic
membranous croup, there is one other circumstance
having a very important relation to this inquiry. As
has already been stated, systematic bacteriological
examination of the throats of patients is not carried
out. The result is that as regards the majority of the
patients treated at home, the medical attendants have
to rely on the indications visible to the naked eye in
deciding as to the freedom of their patients from
infection. It is almost universally agreed that the
throats of such persons, while presenting no indications
of diphtheritic inflammation, may still
contain the bacillus diphtherice in an active and