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APPENDIX A.
[See Standing Order 2.]
Memorandum on Plague Preventive Measures.
Plague, as we know it in India, is a disease of rats in which man
and a few of the lower animals participate. The disease is caused by
the invasion of the body by the plague bacillus. The plague bacillus
is spread from rat to rat, and from rat to man, and to certain other
of the lower animals, by the bite of the rat-flea. The fact that man
is susceptible to the disease is the reason of course that the disease
is of such importance to the public health of India, but it must be
remembered that from the point of view of the plague bacillus, if
such an expression be permitted, man is relatively of small account.
An epidemic of plague among men is but an index of the epizootic
that is raging among the rat population of the community. Were
there no rats, or were rats less " domesticated," or were the habits
and customs of people in this country such that rats found it difficult
to obtain food and shelter in human habitation, plague, as a human
disease, would disappear from India. The fact that the association
between rats and man is so close in this country is the sole reason why
plague is so serious a factor in our vital statistics.
If the significance of these simple facts be grasped, measures for
the eradication of plague as a human disease suggest themselves.
Every effort should be made to induce the people of this country to
\ill\alize that the apathy with which they gladly suffer the rat to share
their food, and find shelter in their homes, is directly responsible for
the fact that they suffer and die from this disease. Once this lesson
has been driven home plague as a human disease will cease to afflict the
converted community.
In the meantime, it is necessary to consider what measures can be
undertaken most profitably to save the people in spite of themselves,
realizing that the degree of success obtainable must depend in some
measure on the amount of co-operation secured.
One of the most remarkable facts about outbreaks of plague in
India is the remarkably constant seasonal prevalence that the disease
exhibits in any given part of the country. For example, plague
epidemics always reach their height in the Punjab and the west of the
United Provinces in the month of April; in the east of the United
Provinces and in Bihar in the month of March; in the south of the
Bombay Deccan about October; in Bombay City, about March. This
phenomenon is explained by the fact that the rat plague, on which
the human epidemic depends, is most acute at that season of the year
when rat-fleas are most numerous. The number of rat-fleas is de-
pendent upon conditions of atmospheric humidity and temperature.
This dependence upon climatic conditions explains, not only why plague
has a constant seasonal prevalence in any given area, but also why the
disease is much more virulent and widespread in some years than in
others. Thus severe epidemics in the north of India have always been
preceded by abnormally damp weather in the cold weather months,