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CHAPTER II.

Autumnal Epidemic Malaria.

   The Punjab has always been looked upon as malarious and though it is so dry
a tract the recorded death rate from fevers is higher than that for most parts of
India.

   A marked feature of Punjab malaria is its seasonal character. During the cold
weather months and the very hot weather following them very little rain falls, and
it is not until June when the monsoon sets in that the conditions become favour-
able to the breeding of anopheles.

   Whether or not from this cause malaria remains in abeyance in the Punjab
until the autumn when in greater or less degree it becomes prevalent.

   The admissions for malaria among troops stationed in unhealthy places in the
Punjab show very regularly an increase commencing in July or even June and
reaching its greatest height in October or November. Investigations at Mian Mir
show that this increase in admissions for malaria is associated with a greater
prevalence of anopheles and a rise in the spleen rate in the native bazaars of the
cantonment. With regard to the infection among troops and the prevalence of
anopheles Wilson1 has shown the same thing for Ferozepore.

   As observations at Mian Mir have now extended over a number of years we are
able to say in regard to this station that there occurs a regular fluctuation in the
level, so to speak, of malaria as shown by the spleen rate and parasite rate.

   This level is lowest during the months of June, July and rises highest in Octo-
ber, falling again during the winter months.

   If we examine the mortality records of the Punjab we shall be struck by an
almost exact repetition in most years of this curve. Especially before plague
appeared and so profoundly modified the seasonal prevalence of deaths we find
the number of deaths lowest in June and July, rising in September, highest in
October and November and falling again through the early months of the year.

   In a paper attached to this report2 is given the result of a preliminary study
of the mortality statistics with reference to the investigation of epidemic disease.
The principle made use of depends upon the fact that if for any given community
the number of total weekly or monthly deaths is plotted out in the form of a curve
this will maintain an approximately level line except when epidemic disease makes
its effects seen in the form of an "epidemic rise." This result of epidemic disease
in India is so enormous that we can study records of its effects even should our

   1 Wilson: Notes on the fevers prevalent at Ferozepore in the Punjab.—Jour. Royal Army Medical
Corps, No. 6, June 1909.

   2 Christophers: Suggestions on the use of available statistics for studying Malaria in India.—Paludism,
No 1, July 1910.