6

REPORT OF THE KING INSTITUTE, GUINDY

    10. Primary vaccination.—The case success rate this year is 96.4 which is
the same as last year. The insertion success rate was 87.6 as against 88.8 last
year. So the general standard of vaccination success has been maintained.

    Table IV gives the monthly success rates. The worst month was May with
case and insertion success rates of 90.3 and 78.3, respectively. The figures from
July onwards are uniformly good. Table V-A gives the district rate in descend-
ing order of case success. Very good results were obtained in the following
districts:—

    As was pointed out in the Annual Report last year these districts have
given uniformly good results since 1923. In the following districts a success rate
below 95 per cent was obtained:—

    It is noteworthy that " Municipalities " with which Madras City is now for the
first time included give a record success rate of 98.6—without Madras it is still a
record of 98.4. The results from Municipalities which on the whole are usually
very much better than those from the districts, have been further analysed for the
first time this year and are given in Table V-B. This has been done in order to
get evidence on the reasons for variations in results in districts, particularly as
to whether such variations are due to changes in the lymph before arrival or to
local causes. Columns 5 and 6 give the crucial comparison between each muni-
cipality and the district in which it is situated as regards the case success rate.
The municipalities are arranged in the order of their districts with descending
success rates as in Table V-A, so in Table V-B, the comparison of columns 5 and
6 in the first portion of the table does not yield any difference of importance, for
though the municipalities have better results than the districts, yet the difference
is not great because the district results are also good. It is when we examine the
latter half of this table that we get the differences that are noteworthy, e.g.,
compare the municipal results with the districts for the five worse districts
already mentioned, viz., Vizagapatam, Guntūr, Nellore, Gōdāvari and Ganjām.
While the rate for the districts runs from 92.9 to 94.5, the majority of munici-
palities in the same districts have rates of 99 per cent or more. To the extent
that these high returns can be relied upon it is probable that there is practically
no variation in the quality of the lymph as received by vaccinators, despite the
variations in time and condition in transit which may be a partial explanation
of local differences in results. There remains therefore to account for the great
variations in districts apparently mainly two explanations and a possible third:—

           (1) Variations in the deterioration of lymph in the hands of the vaccina-
tors during use due to different circumstances,

           (2) Variations in skill including care of lymph,

           (3) Variations in deterioration of lymph during transit before receipt by
vaccinators.

    11. Revaccination.—Details for months and districts are given in Tables VI
and VII. The total number of re-vaccinations was 371,443, i.e., practically the
same as last year, viz., 373,262. The case and insertion success rates are 33.6
and 20.9 per cent respectively.

(B) GENERAL BACTERIOLOGICAL WORK.

    1. Stock vaccines.—Table VIII gives details. The total number of doses
issued is 88,964 which is about 6,600 more than last year. The increase is mainly
due to more cholera and typhoid prophylactic vaccines being supplied.