14
Some Aspects of Anthrax in Bengal [VOL. XVIII, PART I
second on 12 January 1947. The diagnosis in both cases was confirmed on microscopical examination
of films from peripheral blood of the carcases.
It is not desired to draw any conclusions from the small experience with these two herds. It
tends to show, however, that the new Indian Veterinary Research Institute spore vaccine is
perfectly safe for use in cattle and buffaloes in that, it does not give rise to much systemic disturbance
or local swelling, and that the immunity following vaccination may not be expected to last for more
than five months or so.
INADVISABILITY OF LARGE-SCALE ANNUAL VACCINATION
(a) Economic considerations. It has already been stated that the average recorded mortality
due to anthrax amounts to only about 2.6 per cent of the total mortality due to contagious disease
in bovines. While it is neither possible nor advisable to vaccinate every year the entire stock of the
Province (over 30 millions), even in smaller areas such vaccinations are economically unjustified.
Below are examined some data for two small Thana areas in Jhargram Sub-division of Midnapore
district, localities which in the recent past have been affected with anthrax comparatively more
frequently:
—
Total bovines (1945)
Annual mortality due to anthrax (five years' average) .
.
.
.
.
This means one death due to anthrax for every .
.
.
.
.
.
Cost of vaccine for every death due to anthrax .
.
.
.
.
.
Jhargram Thana
52,154
under 5
10,000 bovines
Rs. 2,500
Nayagram Thana
41,037
under 12
3,500 bovines
Rs. 875
(b) Technical considerations. There are scarcely any rural areas, well-defined and limited in
extent, such as villages or small groups of villages, where the disease may be said to be endemic so as
to break out every year or so. Records obtained from the district veterinary assistant surgeons for
the five-year period ending in 1944-45, and covering over 150 villages affected with anthrax, show that
except two villages and one self-contained dairy herd, where the disease broke out twice, the out-
breaks were not repeated in any village. This makes the task of undertaking large-scale controlled
field trials of the vaccine as well as routine vaccination inadvisable. It must, however, be noted that,
in view of the already stated difficulties in the way of correct diagnosis, the possibility of the disease
becoming enzootic in some localities cannot altogether be ignored.
In the past, and even at present, the main suspected causes of widespread epizootics of anthrax
have been lack of (a) prompt diagnosis and control of outbreaks and (6) proper hygienic measures,
chiefly relating to disposal of carcases. For these reasons, it seems, the most profitable method of
tackling anthrax in Bengal would be, one consisting of early diagnosis and institution of immediate
combative measures, including judicious vaccinations and serum inoculations, as well as some well-
organized attempts to ensure proper disposal of carcases. Prophylactic vaccinations on any large
scale are not indicated, either on technical or on economic grounds, except in the case of valuable stock
and, if required in future, in some badly affected localities.
SUMMARY
1. Some aspects of anthrax in Bengal are described and certain relevant features discussed.
2. Anthrax was recognized to occur in Bengal at the inception of the Civil Veterinary Department
in 1892.
3. Since then it has caused mortality chiefly in cattle, but to some extent also in other animals.
4. On several occasions the infection has spread to human beings.
5. Generally speaking, the extent of affection and mortality has been low and the outbreaks have
been small in size.