It is anticipated that if this disease obtains a foothold
in any district it will especially affect "insanitary
areas such as are peopled by the poorest class, and where
overcrowding of persons in houses, and dirt and squalor of
dwellings and of inhabitants tend to prevail."
It is also pointed out that the hygienic conditions in
this country and the methods of dealing with infectious
diseases have been improved to so great an extent that
there has been a large diminution in the mortality from
most infectious diseases, and that typhus fever, " which
as regards the conditions under which it becomes
prevalent most clearly resembles plague," has been almost
exterminated, and it is anticipated that the same measures
will be equally effectual against plague.
The four following facts are insisted upon—
" (1) Plague has an incubation period of 3 to 5 (in exceptional
cases of perhaps 8 to 10) days.
" (2) Plague is wont, especially in its earlier manifestations,
to assume a mild form, or even to present
anomalous symptoms, tending to confound it with
other and more innocent diseases.
" (3) Plague in all its forms must needs be regarded as
"(4) Plague affects rats as well as the human subject;
it may, indeed, be found causing mortality among
these lower animals antecedent to its definite invasion
of the population. There can be no doubt
that the rat and man are, as regards plague, reciprocally
Plague is made a notifiable disease, and with a view to
assisting medical attendants in its diagnosis the symptoms
of the disease are described in detail.
Besides the general methods of precaution set forth in
the General Memorandum, " the prompt destruction of all