8
Septicæmia serum, 3,133 doses of which are now available for immediate issue,
and a much larger supply will be forthcoming in a few weeks' time for use
during the coming rainy season.
At present, a series of experiments are being prosecuted with a view to
ascertain the period during which immunity persists, when animals are
injected with serum only, as is carried out in the case of bovines and buffaloes
exposed to the virus of rinderpest in various epizootics.
31. A separate brochure will be submitted detailing the points of interest
observed in the course of Hæmorrhagic Septicæmia in this country, as soon
as time will permit.
32. Surra in camels.-Of the three camels, the subjects of surra placed
under daily observation from 23rd November 1902, up to date, two succumbed
to surra during the rains of 1903, while the third, attacked during the rains of
1902, survived but exhibited trypanosomata in its blood at intervals up to the
5th April 1904, and probably through the rains. Between this latter date
and November 14th, 1904, the blood was not examined. But from the 15th
November, a systematic examination was conducted daily and it elucidated the
fact that the trypanosoma was absent on the first examination and ever since ;
further, that equines inoculated with 20 c. c. of blood drawn from the. general
circulation, failed to contract the disease. This experiment proves that the
general opinion held by the camel sowars, viz., that camels if capable of
passing through a period of Surra lasting three years and termed by them
Tibursa, will eventually recover, was quite correct.
33. An extensive series of experiments with regard to the etiology, etc.,
of the camel trypanosoma have been undertaken and the results when ready
for publication, will be submitted to the Government in a separate report.
34. To attempt a prophylactic or curative serum.—As early as 1894, I
treated equines (Surra) with the intermission blood, and also hyper-immunized
cattle with equine surra blood drawn during both paroxysms and intermissions
of the disease, but the curative effects of the respective sera were found to be
inefficient with regard to bringing about a cessation of the T. Evansi in the
equines thus treated. More extensive experiments were conducted during
1897—1902, with the result that sera respectively obtained from numerous
bovines, previously hyper-immunized during long periods with defibrinated
horse blood, were found to possess the power of destroying vast numbers of
trypanosomata after an exposure of 2½ minutes "in vitro." Repeated doses
of these sera injected subcutaneously with equines suffering from surra, were
found to possess the power of destroying the mature flagellates present in the
circulation of the host. But although they kept the disease in abeyance for a
time apparently, nevertheless, in the end these sera utterly failed to destroy
the immature forms of the flagellates " in vivo, " and the animals thus treated
ultimately succumbed to Surra.
35. Further trials, however, will be conducted with hyper-immunized
bovine serum, in combination or concurrently with other forms of treatment .
and later, the preparation of a prophylactic will be entertained.
36. To attenuate the trypanosoma by means of cultures.—During the past
six months of the year under review, large numbers of experiments have been
conducted with a view to obtain pure cultures of the T. Evansi, T. Equiperdum
and T. Lewisi under various conditions as regards culture media. A certain
proportion of the experiments have been successful and the best results have
followed the use of equine, instead of rabbit defibrinated blood, as recom-
mended.
This line of investigation is only in its infancy and much remains to be
accomplished before anything worth recording can be looked for.
37. To attenuate the trypansoma by passing though the body of animals
other than equines.—Surra (T. Evans) is an absolutely fatal form of disease
in equines, death occurring in the majority of cases within 50 days. Attempts
were, therefore, made to attenuate the virus by the passage of the trypanosoma
through some other species of animals previous to the inoculation of
equines. For this purpose, a horse was inoculated with the trypanosoma