NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
22
Studies on Newcastle (Ranikhet) Disease Virus
established only after the 7th day and is solid on the 14th and 21st days.
In the previous experiment, it appeared that there was satisfactory immunity
11 days after the vaccination. If this method of preventive treatment is to
prove practicable on any large scale, it will be necessary for the birds sub-
jected to prophylaxis by crystal violet vaccine to be segregated from the
infected surroundings for a period at least of 14 days to obviate the risk of the
birds contracting the infection during the negative phase. It will be further
seen from this experiment that 14 days after vaccination, three fowls with-
stood the infection by pen-contact.
Vaccine does not disseminate infection. From the fact that a healthy fowl
placed along with the vaccinated fowls for a period of 14 days remained un-
affected (Table V), but died when exposed to the infection, the vaccine does
not appear, to be capable of disseminating the disease from the vaccine-
treated birds. At this stage with the limited experiments and observations,
it would not be justifiable to claim that the vaccine is definitely free from
any unmodified virus capable of returning to its virulence under some suitable
conditions. The results, however, warrant a further extensive trial of the
vaccine. So far, the immunization experiments have been restricted to one
strain of virus only, that is, the English strain. It would be interesting to
know if, by this method, other strains of virus, such as the Indian strain,
against which primarily this work was initiated, would yield to similar bio-
logical modification.
Experiment IV. To confirm the promising results so far achieved, im-
munization work with further lots of crystal violet treated egg virus was
undertaken. In this experiment, the virus used had undergone 41 serial
passages through eggs and a larger number of birds and controls employed.
The birds were housed together in a pen with common food and water. Twelve
fowls were inoculated with 5 c.c. of the vaccine subcutaneously, and
12 control fowls of almost the same weight and breed were placed with these
and allowed to mix freely so that the possibility of dissemination of Newcastle
disease consequent on vaccination could be ascertained.
Results. There was no reaction in any of the fowls but subsequent
observations were impossible owing to an outbreak of fowl pox among these
experimental birds. This experiment is, therefore, not recorded in
Table V.
TABLE V
Egg virus crystal violet vaccine for Newcastle disease
Vaccine
lot No.
I
II
Date of
inoculation
5 Feb. 1940
29 Mar. 1940
Fowl
No.
2137
2878
2879
Inoculum 5 c.c.
subcut
Passage 12 . .
Passage 23 . .
Result of
vaccination
Remained well .
Do
.
Result of immunity
test
Contact infection on 30
March 1940, died
Immune to one million M. L.
D. on 9 April 1940, and 100
million M. L. D. on 22
April 1940; control fowls
died
S.
GANAPATHY
IYER
23
TABLE V—contd
Vaccine
lot No.
III
Date of
inoculation
2 May 1940 .
Fowl
No.
2273
2274
2275
2276
2278
2277
2279
2287
Inoculum 5 c. c.
subcut
Passage 33 . .
Do . .
Do . .
Do . .
Control egg virus
plus saline
Left in contact with
the
vaccinated
fowls inside pen
Result of
Vaccination
Remained well
Do . .
Do . .
Do . .
Do . .
Do . .
Result of immunity
test
Contact infection on 16 May
1940 and 100 million M. L.
D. on 7 June 1940, immune
7th day inoculated fowl virus,
died 4th day
14th day inoculated fowl
virus, immune
21st day inoculated fowl virus,
immune
14th day inoculated fowl virus,
immune
14th day contact infection,
died 6th day, whereas none
of the vaccinated fowls
exposed to similar infection
died
(iii) Formalized egg virus
Experiment I. Newcastle virus cultivated through 12 generations in
eggs was used. To a one per cent suspension of infected embryo in phosphate
buffer, pH 7.6, formalin was added to a concentration of 0.2 per cent and
the mixture was attenuated at 37°C. for 72 hours. Inoculations were made
as follows:—
TABLE VI
Formalized egg virus
Date
of
inoculation
5-2-40
5-2-40
Fowl
No.
2139
2138
Dose
and
route
5 c.c. S/c
„
Result and remarks
Survived, tested immunity 28 February 1940,
died 4 March 1940
Control, virus and saline kept 37°C. 72 hours, died
4th day.
There was no protection following inoculation with formalized egg virus.
Formalin had rendered the virus inert, for the control fowl died of Newcastle
disease ; the virus was, therefore, fully virulent even after incubation at 37°C.,
for 72 hours. It may be recalled here that Beard, Finkelstein, Sealy and
Wyckoff [1938] obtained favourable results in the process of vaccination
against equine encephalomyelitis with formalized vaccine using virus pro-
pagated through eggs. In the preliminary experiment for Newcastle dis-
ease detailed above, similar results could not be obtained (Table VI).
Experiment II. Another sample of formalized vaccine from egg virus
after having undergone 27 passages was prepared and tested in fowls. In
this case, 10 per cent tissue emulsion was used and the concentration of forma-
lin was 0.4 per cent and the mixture attenuated 48 hours at 37°C. (Table VII)
24
Studies on Newcastle (Ranikhet) Disease Virus
TABLE VII
Attenuated egg virus and formalin
Date
of
inoculation
13-4-40
13-4-40
Fowl
No.
2223
2224
Dose
and
route
5 c.c. S/c
„
Result and remarks
Survived, immunity test on 22 April 1940, died
4th day
Ditto
Results. Formalin has, therefore, no apparent value in the preparation
of a suitable vaccine from egg virus. As a result of the extended observations
on the immunizing property of egg virus or other kinds of vaccine made sub-
sequently, it should be mentioned, at this stage, that the period elapsing
between vaccine treatment and the subsequent exposure of fowls to the virus
of known virulence seems to be a most important factor for consideration.
Since more promising results were obtained with egg virus alone, formalin was
given no further trial.
DISCUSSION
For the control of Newcastle disease of fowls which is responsible for
enormous losses to the poultry industry in countries where it is endemic,
there has not admittedly been, as yet, developed any preventive or curative
treatment whose value has been proved under controlled laboratory experi-
ments. In this paper, are described methods for the immunization of fowls
against the Newcastle virus. It has been shown that the fully virulent Eng-
lish strain of the virus from an infected fowl, consequent on continued passage
through the developing chicken embryos, undergoes a change after a certain
number of passages while at the same time, retaining its immunizing value.
The virus was sufficiently decreased in virulence to suggset its use as a live-
virus-vaccine. Whilst it continued to remain lethal for the embryo, it pro-
duced only what may be considered as a ' silent infection' in inoculated fowls.
The resulting immunity of these fowls against fowl-passage virus of known
virulence, by contact infection or by experimental inoculation was solid
in almost all cases. From 14 to 33 serial passages through the developing eggs
seem necessary before the strain of virus can be rendered safe and reliable for
immunization work. The possibilities of further attenuation and return to the
original virulence or exaltation of the virus owing to its passage through the
eggs for an indefinite period are being investigated. Some of the experiments
in hand now suggest that, owing to the individual variation in the suscepti-
bility of fowls, one may encounter a small percentage of reactors.
It has also been shown that a satisfactory vaccine for Newcastle disease
may be prepared from the egg propagated virus (not fowl passage virus)
by treatment with crystal violet; the method is somewhat similar to that in
S. GANAPATHY IYER 25
use for the control of swine fever in the United States Department of Agri-
culture advocated by Dorset. While investigating some of the conditions
which might affect the successful employment of the crystal violet vaccine
against Newcastle disease, there were indications that, owing to certain vari-
ations in the individual susceptibility of fowls, it might offer certain diffi-
culties militating against a satisfactory standardization of the vaccine.
Within the limits of the present experiments and the scope of the preliminary
immunological work, there are indications that the use of crystal violet with
the egg cultivated virus in the preparation of the vaccine against Newcastle
disease can with advantage and impunity be eliminated. Further work is
being carried out to investigate the various factors which may influence the
successful employment of these methods of preventive treatment.
It is hoped that a preliminary report of this nature will be of value in
solving the vexed problem of controlling Ranikhet disease in India by under-
taking wholesale immunization of flocks in endemic areas.
ACKNOWLEDGEMENTS
The author wishes to express his gratitude to Dr W. H. Andrews, Director,
Veterinary Laboratory, Ministry of Agriculture and Fisheries, Weybridge,
England, for the various facilities given to him during the prosecution of this
work.
His thanks are due to Mr T. M. Doyle for his helpful suggestions ; to Mr
N. Dobson, for his professional cooperation and immense help ; to Mr L. E.
Hughes for assistance in histo-pathology and to Mr A. Norman for his excellent
photographs.
In the preparation of this article the author received considerable advice
and constructive criticism from Mrs L. H. Shirlaw, B.A.; therefore, his grate-
ful thanks are also due to her.
REFERENCES
Acevedo, R. A. (1933), Gaz. Bureau. Anim. Indust. Philippine Is. 3, 80-7
Beaudette, F. R. and Hudson, C. B. (1938). J. Amer. Vet. Med. Ass. 93, 146-50
Beaudette, F.R. and Hudson, C. B. (1939). J. Amer. Vet. Med. Ass. 75, 333-39
Beard, J. W., Finkelstein, H., Sealy, W. C. and Wyckoff, R. W.G. (1938). Science
87, 490
Bedson, S. P. (1938). Brit. J. Exp. Path. 19, 353-66
Bengston, I. A. and Dyer, R. E. (1935). Pub. Health Rep. Wash. 50, 1489-98
Brandly, C. A. (1937). J. Amer. Vet. Med. Ass. 90, 479-87
Brandly, C. A. and Dunlop, G. L. (1939). J. Amer. Vet. Med. Ass. 95. 340-9
Burnet, F. M. (1933). J. Path. Bact. 37,107
Burnet, F. M. (1934). Brit. J. Exp. Path. 15, 52-5
Burnet, F. M. (1935). Med. J. Aust. Nov. 16th, 687-9
Burnet, F. M. (1936). Med. Res. Council. Sp. Rep. Series No. 220, London
Burnet, F. M. and Ferry, J. D. (1934). Brit. J. Exp. Path. 15, 56-64
Cooper, H. (1931). Ind. J. Vet. Sci. Anim. Husb. 1, 107-23
Coronel, A. B. (1939). Philipp. J. Anim. Indust. 6, 43-54
Crawford, M. (1930). Rep. Gov. Vet. Surgeon, Ceylon
Dobson, N. (1939). Proc. 7th World's Poult. Congr., 250-3, Washington, D. C. : U. S.
Dep. Agric.
Dorset, M. (1935). Vet. Bullet. 9, 206
BRUCELLOSIS IN INDIA
BY
J. B. POLDING
Research Officer, Imperial Veterinary Research Institute, Mukteswar
(Received for Publication on 25 July 1942)
I NVESTIGATION of contagious abortion in India has been the subject of
an Imperial Council of Agricultural Research scheme for a period of over
three years and it has been observed that Brucellosis is by far the most
common cause of this condition in Indian bovines. This article, therefore,
has been written with the object of indicating what has so far been achieved in
the study of this disease, as it occurs in the Indian subcontinent.
The investigation of Brucellosis in India, however, is not yet complete
and in any case there is no limit to the amount of information that it seems
desirable to acquire concerning so wide-spread a disease. In order, therefore,
that Indian veterinarians may have readily to hand, as much instruction as
possible on the diagnosis and control of the disease, a series of appendices
describing some useful technical methods have been prepared and are
obtainable from the Director, Imperial Veterinary Research Institute, Muktes-
war—Kumaun, U. P.
The bacterial subspecies responsible for Brucellosis in India
The genus Brucella is usually considered to contain 3 variants, or sub-
species, viz. Brucella abortus, Brucella melitensis, and Brucella suis ; neverthe-
less variants occur which are intermediate between any of these types. The
host of predilection of Br. abortus is the bovine, of Br. melitensis the goat
and of Br. suis the pig. Occasionally these hosts may be interchanged and
all variants may at times occur in almost any other animal, including man.
Up to the present time, 46 Indian Brucella strains have been secured by
the writer. Of these, 22 have been typed as pure abortus ; 18 as intermediate
between abortus and melitensis; and 3 as melitensis. The remainder were
either lost before typing or have not yet been typed. Table I shows the
hosts of origin and the character of these strains. It is noticeable that only
3 melitensis strains and no suis strains have been encountered ; and that of the
3 melitensis strains, one came from man, one from a goat and only one from a
cow. It is also to be observed that all 4 village strains are typed as abortus¬
melitensis*, from which it is tentatively suggested that the indigenous Indian
Brucella strain is of this kind. It may also be seen from the table that
organized dairy farms are about equally infected with this type and the
imported English type Br. abortus.
*The term dborlus-melitensis refers to an intermediate strain, exhibiting some characteris-
tics of Br. abortus and some of Br. melitensis.
27
28
Brucellosis in India
TABLE I
Indian Brucella strains
Host
Dairy Cow . .
Village Cow . .
Buffalo (Dairy) . .
Goat . .
Horse . .
Man . .
Total.
No. of strains
isolated
20
4
16
1
1
1
43
Typed as
A
11
0
10
0
1
0
22
A/M
8
4
6
0
0
0
18
M
1
0
0
1
0
1
3
A = abortus, A/M — abortus / melitensis, M = melitensis
It is not usually feasible to distinguish the variant responsible for an
outbreak of Brucellosis without first isolating the strain involved. The
more strains that can be procured, therefore, the greater will be the amount of
information available on the character of Indian infections.
The susceptibility of Indian stock to Brucellosis
As has been previously stated, almost all the higher mammals can on
occasion become infected with Brucellosis ; but, as in India the commer-
cially important animals are cattle, sheep and goats, the following remarks
are confined only to these species. Nevertheless, because observations are
almost always influenced and obscured by other factors, such as climate
and animal husbandry, it is difficult at present to give reliable figures illustrat-
ing the relative susceptibility of even these animals. On the whole, however,
the conditions in Military Dairies and such like farms do not differ widely
throughout Northern India ; hence a statement drawn from an aggregate of
these is not unworthy of consideration. Again, although it is possible that
their climate is on the whole less likely to favour the spread of Brucellosis
the Punjab Grantee farms also merit consideration, as they are run on a system
similar to that of the Military Dairies and they are probably the best available
source of information on pure indigenous cattle. The following figures
relating to such farms are abstracted from the records of this Institute.
TABLE II
The relation between the incidence of Brucella reactors and the occurrence o
European blood in Military Dairy Farms
Military Dairy
Allahabad . .
Ambala
.
.
Quetta . .
Lahore .
.
Ferozepore . .
Average
Percentage
of crossbreds
in
herd
90
82
80
17
1
54
Percentage
of Brucella
reactors
50
45
39
24
13
34
J. B. POLDING 29
TABLE III
The relation between the incidence of abortion and the occurrence of European
blood in Military Dairy Farms
Military Dairy
Allahabad . .
Ambala . .
Quetta . .
Lahore . .
Ferozepore . .
Average...
Porcent-
age of
crossbreds
in herd.
90
82
80
17
1
54
Percentage of aborters
All
breeds
42
25
30
10
10
22
Cross
breeds
45
27
33
4
0
21.5
Indige-
nous breeds
20
16
17
11
10
15
The term ' aborters ' refers to animals with a history of abortion present in the
herd at the time of a single random observation.
The figures in Tables II and III tend to show that the higher the propor-
tion of European blood in a herd, the higher is the incidence of infection
in all classes of animals.
TABLE IV
The percentage of aborters present at a single random observation in the classes of
stock indicated
Class of animal
Crossbred stock of 15 Military Dairy Farms .
.
.
Country-bred stock of 13 Military Dairy Farms . . .
Buffaloes of 15 Military Dairy Farms
.
.
.
Indigenous cows not in contact with crossbred cattle (Northern
India)
Buffaloes not in contact with crossbred cattle (Northern India)
Buffaloes in special environments (1 farm) . . .
Indigenous cows in special environments (3 farms) . . . .
No. of
animals
observed
1,333
164
1,880
4,495
895
281
502
Percent-
age of
aborters
16.0
7.5
5.0
3.5
3.5
15.5
3.5
Northern India is taken to be the territory north of a line drawn from Bombay
to Calcutta, Bengal and Assam excluded.
From Table IV it will be seen that:—(1) the largest number of abortions
occur in the crossbred stock of Military Dairies, (ii) the rate of abortion in the
country-bred stock of Military Dairies is about half of that in crossbred stock,
(iii) the abortion rate in the buffaloes of Military Dairies is rather less than that
in the country-bred stock in the same establishments, (iv) the abortion rate
is about equal in country-bred stock and buffaloes when neither is in contact
with crossbred stock, but, at the same time, is less than that in the same sort
of stock when it is co-habiting with crossbred animals. The last two cate-
gories listed in Table IV require some discussion. The special environments
mentioned are the conditions of animal husbandry in and around Bombay.
30
Brucellosis in India
These conditions will be discussed more fully in a later section, and it is suffi-
cient to say here that buffaloes in this environment show a startling increase
in the rate of abortion as compared with the rate in the Punjab, whilst cows
in the same environment show the same rate as for Northern India. The
numbers recorded in these classes are small, especially in the case of buffaloes,
as figures are difficult to obtain from many Bombay farms. Nevertheless,
many additional farms have been examined and in the absence of records the
general impression received supports the figures shown in the table. It is
concluded, therefore, that when buffaloes are removed from their natural
environment, they become much more susceptible to Brucellosis than similarly
moved indigenous cattle. Indeed, in these circumstances, their susceptibility
perhaps reaches or even surpasses that of the crossbred cows of Northern
India.
There is some evidence to show that either the susceptibility of Indian
cattle is decreasing, or that better methods of animal husbandry are limiting
the spread of Brucellosis. Table III was constructed from records made
during the period 1924 to 1929 and Table IV from figures collected from 1939
onwards. It is noteworthy that the average number of abortions in the former
table is greater than that in the latter. Again, the annual reports of
the Military Dairy Farm show a progressive decrease in abortions from all
causes during the years 1932 to 1939. Lastly in 1923, the mean number of
abortions present at a single random observation on 5 Punjab Grantee farms
was 3 per cent of the 1264 animals observed, while at the time of the
writer's visits in 1939, this figure had fallen to 1 per cent of 835 animals. If
this decrease is indeed due to a reduction in susceptibility, it may only repre-
sent a phasic decrease, but if it is due to better animal husbandry then the
decrease is likely to be permanent.
The susceptibility of various classes of stock to repetitions of abortion is
shown in Table V.
TABLE V
The likelihood of repeated abortions in various classes of Indian stock
Class of stock
Crossbred cows
Country-bred
cows
Buffaloes
Percentage of animals aborting
Once
79.5
90.0
90.0
Twice
17.5
9.0
10.0
Thrice
2.5
1.0
0.0
Four
times
0.5
0.0
0.0
Average
expect-
ation of
loss of
calves per
aborter
1.24
1.11
1.10
Popula-
tion
observerd
198
75
91
Assuming that the percentage abortions shown in Table IV are correct
then amongst 100 crossbred cattle 16 may be expected to be aborters and
their total loss of calves would be 16 × 1.24 =19.84 calves. The same fig-
ures for country-bred cows and buffaloes work out at 8. 33 and 5.5, respective-
ly, and by making the last figure unity, the preceding figures would be
34
Brucellosis in India
Another system is becoming increasingly popular overseas, namely
vaccination, but as its practice has only lately been taken up seriously in India,
it is not yet possible to give details of the method. For general guidance,
however, it may be said that the method of vaccination at present in vogue
consists of a single subcutaneous injection of 5.0 c.c. of a saline suspension of
low virulent strain of Brucella organisms. The most suitable subject for
vaccination is the calf or the heifer and vaccination is mainly recommended
in badly infected herds maintained under adverse conditions. In certain
circumstances adult animals can be vaccinated. At present, nothing can be
said as to the duration or degree of protection offered by this form of
immunization in India but from reports of overseas experiments it appears
that, given the right circumstances, an annual abortion rate of say 20 per cent
can be reduced to about 3 per cent. Up to the time of writing, between two
and three hundred animals have been vaccinated in India, and so far no un-
fortunate sequelæ have been observed. The immediate reaction to the
injection is a slight rise of temperature on the second and third days, together
with a local swelling at the site of injection which is rarely larger than a
man's hand and which disappears completely in a week or 10 days.