10

SUPPLEMENT TO THE ANNUAL REPORT OF THE

          2.  Well irrigation which lowers the sub-soil water level should be encourag-
ed. We suggest that it is a measure generally applicable that when canal irrigation
raises sub-soil water level, well irrigation which then is easier should be insisted
on and thus canal water would be saved for use elsewhere.

          3.  In the new situation caused by the proposed change to dry crop irrigation
such obvious minor anti-malarial measures as remain should be carried out, e.g.,
the draining or filling up of any breeding places near villages and the clearing
away of jambo grass from canals.

          4.  A temporary dispensary should be established in the area and that before
September. The most suitable village seems to be Botlagudur which is fairly
central. Perhaps a travelling dispensary would serve.

          Conclusion.—This survey, subject to confirmation by a second visit in the
autumn, shows that great changes have been produced in the Mopad area by
irrigation of wet crops leading to the area becoming highly malarious. The
history appears to afford another instance of the absolute necessity for early
co-operation between the Engineer and Agriculturist on the one side, public
health workers on the other.

          Addendum.—The report on Duttalur should be read along with this report
because it gives good evidence of the degree of malaria in control dry crop
villages.

SECOND REPORT ON MALARIA IN MOPAD (NOVEMBER 1926)

By LIEUT.-COL. H. H. KING, I.M.S.

AND

CIVIL ASSISTANT SURGEON M. K. RAMASWAMI AYYAR.

          1.  Introduction.—The first report dealt with conditions in March 1926, so
final conclusions were withheld until another visit could be made in the autumn
during or just after the monsoons when malaria was at its worst. Accordingly
an investigation unit under Assistant Surgeon M. K. Ramaswami Ayyar went to
Mopad in November 1926 and has submitted a report on which this is based. In
December the unit was assisted by Mr. P. V. Sitaram Ayyar, who is an Entomo-
logist and Zoologist in this Institute. Tables, etc., in this report are numbered
consecutively with those in the first.

          2.  Monsoon conditions.—Unfortunately for some of the objects of the second
enquiry not only had the south-west monsoon been deficient but the north-east
monsoon, the principal monsoon in these parts, practically completely failed. The
rainfall for 1926 for the whole year was only 15.8 inches, while the average in the
last decennium was 32.2 inches. The rainfall in October, November 1926 was
only 3.09 inches as compared with the decennial average for these two months
together of 16 inches—see chart 1 (not reproduced) of the previous report.

          3.  Malarial conditions in November and December 1926.—Villagers stated that
malaria at this season was less prevalent than in previous years. Though this
was the case, yet, the conditions for epidemic malaria were still eminently
suitable. Adult anophelines existed almost in clouds. Assistant Surgeon Rama-
swami Ayyar says that he had never before seen so many mosquitoes together as
he saw in the Mopad area, and that judging from the mosquito population he
would have expected to find a very severe epidemic going on. Fresh infections
were still occurring so much so that a member of the unit got malaria, but not to
the extent of causing a severe epidemic. The reasons for this probably were
firstly the atmospheric conditions were less favourable than in previous years due
to the failure of the monsoon, and secondly the increased quinine treatment.
received at the time of and since the visit of the previous unit. This quinine was
supplied by the District Board through the Health Officer, Nellore. We find it