FOR THE YEAR ENDING THE 31ST MARCH 1938.                          19

General Remarks on Disease Control.—The results of the inoculation
campaign against Rinderpest with Goat Vaccine have now reached a
stage when it is possible to estimate the value of the vaccine as an
immunizing agent, the probable extent of its application in the districts
in the future and the difficulties which the Department will be faced
with in carrying out inoculations.

The inoculations carried out during the last two years in clean and
outbreak areas have had the effect of reducing the mortality in 1937-38
to 11,161 from 31,071 in the previous year. The graph shown in
Appendix A of the Annual Report indicates that since 1930-31 there
has been a decided tendency for the disease to show a recrudescence
similar to that shown in the years 1908-09 to 1910-11, 1916-17 to
1919-20 and 1924-25 to 1925-26. The work of control of the Depart-
ment, assisted very materially by vaccination with Goat Vaccine, has
depressed the curve due to have reached its peak about 1936 and
prevented the disease from assuming the proportions shown in the
graph in previous periods of periodic recrudescence.

Reference to the mortality figures for the various Veterinary Circles
shows that in the two Circles where Cattle Breeding is not generally
practised and in which cattle are mostly purchased for cultivation work
(South-Eastern Circle Tenasserim and South-Western Circle, Irrawaddy)
the prevention of the introduction of diseases into the Circles as far as
has been possible, together with the general immunization of animals by
vaccination, has reduced the incidence of disease in these Circles during
the year to a few sporadic outbreaks involving very little mortality.

In Upper Burma where susceptible young stock are constantly being
bred, where good roads favour cattle movements in herds and in carts
and where there is a continuous introduction of cattle from infected
trans-frontier areas with imperfect supervision at importation, the
results of the inoculation work have not been so satisfactory. Cattle in
Upper Burma are more difficult to collect for inoculation owing to larger
numbers of animals in the herds and also to the fact that a considerable
proportion of all village herds are untrained young stock and wild cows.
In consequence of this and the general apathy of owners, the percentage
of cattle which can be inoculated in the herd may vary from 20 per
cent to 75 per cent.

As their percentage rises these unvaccinated cattle progressively
reduce the value of the protection given to the herd by artificial
immunization and they have been the cause of frequent recrudescence
of the disease in the Yamèthin, Meiktila, and Toungoo Districts during
1937-38. Under present rules it is only possible to insist on immuniza-
tion of all animals in the affected herd in the presence of an actual
outbreak and it is then too late to prevent spread of infection as the
staff is unable at present to cope with all demands for inoculations when
the disease is widespread.