5
It must be understood that virulent rinderpest material, both plain and
hill, cannot always be obtained when most needed for laboratory purposes.
In future, however, efforts will be made to maintain the intensity of the virus,
by securing fresh virulent material at short intervals, whenever possible.
Tests made with this material (in virulent form) should insure the immediate
detection of any deterioration which may possibly have occurred, and thus
the potency of the serum prepared would be assured.
19. The above discovery is one of great importance to us in the preparation
of rinderpest sera and, of necessity, materially reduced the total output during
the past 12 months. But this reduction is compensated for by the knowledge
that the dose of serum, as now issued, is probably capable of combating the
most virulent form of the disease as met with in India (hills).
It may be argued that most probably the doses of serum as issued were
sufficient to protect the great majority of animals against rinderpest in the
plains, but it is an extraordinary occurrence that full doses of the sera in
question failed to protect plains animals by the simultaneous method when
the new strain of rinderpest blood was used for the purpose, in experiments at
the Laboratory. Further, that plains animals with much enhanced doses to
those primarily injected succumbed to the disease, until a dose was arrived at,
equivalent to 1/18 the dose of serum required to protect hill cattle, when the new
strain of virulent rinderpest blood was utilized.
20. It is a source, however, of great satisfaction to record that no com-
plaints of insufficient doses of serum have been received, in any instance, from
Superintendents, during the issue of No. XXIV serum. From the researches
made at the Laboratory, I find that hill cattle which succumb to fairly large
doses of anti-rinderpest serum when tested by the simultaneous method (i.e.,
blood and serum at the same time on opposite sides of the body) do not
succumb when animals are first injected with a small quantity of serum and
at a later period (48 hours), receive virulent blood or are driven amongst an
infected herd as in the plains, in order to contract the disease and undergo
the simultaneous method in a modified form. These results may explain in
the case of plains animals, (which generally exhibit much less susceptibility to
rinderpest than the hill cattle,) why the small dose of serum when injected
into the former was sufficient to guard against infection. On the other
hand, from a practical point of view, it is probable that of a large number
of plains cattle injected with anti-rinderpest serum, only a small number of
them would come in contact with infected members of such herd in the field
and, therefore, the majority would run but a minimum chance of infection.
21. Experiments were initiated and continued with a view to the produc-
tion of a prophylactic capable of conferring immunity on bovines, etc., in order
to avoid the necessity of hyper-immunizing cattle with large quantities of
virulent blood, but nothing can of course be stated at this stage with regard to
the results, etc., until something conclusive is arrived at.
22. As desired by Government, the serum in dry form was prepared for
experimental purposes by Captain Holmes and its utility tried in the field.
The results submitted by the respective Superintendents who utilized the
serum will be found in the following section.
One great advantage in its favour is that the serum in powder can be
distributed in much smaller bulk. A great disadvantage, however, is that no
carbolic or other antiseptic can be added to this in dry form, and the powder
must be used within 24 hours after solution has been made. Thus, it will
throw much work and responsibility on the Superintendents, as it would be
impossible to trust the majority of Veterinary Assistants for this particular
work in the field.
The use of this powder is distinctly indicated in cases where the services
of officers or trained and trustworthy subordinates can be ensured for the
preparation of the solution for subcutaneous injection, and further, I should
imagine that its greatest use will be found to be in the case of expeditions—
military or otherwise—where large numbers of transport animals are employed.
23. Rinderpest in camels.—The question has often been asked; are camels
in India susceptible to spontaneous or inoculated rinderpest or both ? Unfor-
tunately, no literature in this country bearing on this subject is forthcoming