NationalLibraryOfScotland/medical-history-of-british-india huggingface dataset:
184
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STUDIES IN DAY-OLD CHICK IMMUNIZATION AGAINST
FOWL POX USING EGG-PROPAGATED FOWL
POX AND PIGEON POX VIRUSES
By S. B. V. RAO, B. M. THAKRAL and V. V. SRINIVASAN, Division of Poultry
Research, Indian Veterinary Research Institute, Izatnagar
[ Received for publication on June 4, 1957
Accepted for publication on June 1, 1958]
With 4 Text-Figures
T HE occurrence of fowl pox in India in the hot summer months causing severe
morbidity [Figs. 1 and 2] and mortality in chicks even during the first few weeks
of their life is a matter of common knowledge to all poultrymen. It has been the
routine practice to vaccinate young chicks with pigeon pox scab vaccine, the
use of a similar material from fowl pox skin lesions having proved hazardous owing
to generalization and flare up of the disease in some of the flocks. However, the
use of pigeon pox scab material for immunizing baby chicks of early age was not
a success. The Disease Investigation Officers' Conference held in March, 1950,
suggested that since the pigeon pox vaccine in use at present had a low degree and
duration of immunity, it should be improved to avoid serious recurring losses to
the poultry industry, and that experiments should also be conducted to immunize
chicks of much lower age than eight weeks.
LITERATURE
Fowl pox virus immunization
Dunn and Sherwood [1932] reported successful vaccination of day-old chicks
with fowl pox skin lesion virus with no constitutional or systemic symptoms, and
concluded that it was of practical value for protecting baby chicks, provided due
care was exercised in the process. The first of a series of large-scale experiments,
both in the laboratory and field, was carried out by Lubbehusen and Ehlers [1936].
They laid special stress on (i) the technique, (ii) the site of vaccination and (iii)
the careful selection of a vaccine in suitable dilution which would give a high per-
centage of takes without favouring secondary pox lesions or untoward sequelae.
The criteria for the success of the vaccination were the data regarding the weight
gains and mortality, as compared with the non-vaccinated controls, and the degree
of immunity conferred. Their conclusions were that vaccination of day-old
chicks with skin lesion virus of the fowl was accompanied by a systemic reaction
which manifested itself by a temporary inhibition of normal weight gains and
lowering of vitality, the degree of which was influenced by the local reaction which
in the presence of unfavourable conditions and intercurrent infections, contributed
to excessive mortality.
187
78 AR/58
4
December, 1958]
RAO
et al.
189
Fig. 1. Pox infection in chicks within five weeks of age ; malignant form
Fig. 2. A group of five-week old chicks in brooder affected with pox
December 1958]
RAO
et
at.
191
Fig. 3. Papule one week after day-
old chick vaccination with
F. P. V. virus
Fig. 4. Pustule two weeks after F. P. V.
vaccination of day-old chick
192
STUDIES IN IMMUNIZATION AGAINST FOWL POX [Vol. XXVIII, Pt. IV,
Growth-rate
The growth rate of group I did not show significant difference as compared
with the control, but the 9 per cent of chicks which developed secondary
lesions were visibly stunted in their growth as against a 4 per cent runts in the control
due to other causes. The rate of mortality was 8 per cent in vaccinated ones and
6 per cent in the controls. (The average weight per chick in groups I and II, and
mortality are shown in Tables I and II.) In the second group the secondary lesions
were fewer in number (4 per cent). The growth-rate showed little deviation from
the normal. The mortality was 8 and 9 per cent in the vaccinated groups I and
II and 6 and 8 per cent in the control groups respectively.
TABLE I
Showing growth-rate of F. P. V. vaccinated and control chicks
Serial
No.
A
B
Group
Vaccinated . .
Control. . .
Vaccinated . .
Control . .
No. of
chicks
100
100
100
100
Average body weight in grams
Day-old
37.8
38.3
38.5
38.3
2 weeks
92.9
84.6
75.6
76.7
4 weeks
174.2
181.0
130.7
136.5
6 weeks
305.0
300.0
211.4
214.3
8 weeks
439.0
443.3
302.5
307.0
TABLE II
Showing results of vaccination with egg.adapted F. P. V. in day-old chicks
Group I
Rhode
Island
Red
Group II
Barred
Plymouth
Rock
No. of
chicks
100
100
(control)
100
100
(control)
25
(in-
contacts)
Vaccine
per cent
8
..
4
..
..
Takes
per cent
100
..
96
..
..
Secondary
lesions
per cent
9
..
4
..
7
Runts
per cent
9
4
4
4
7
Mortality
per cent
8
6
9
8
8
Percentage refractory
to challenge
8 weeks
after
vaccina-
tion
100
0
100
0
80
12 months
vaccina-
tion
100
0
10
00
..
December, 1958]
RAO
et al.
193
Immunity tests
Five chicks were challenged each time from the first and second vaccinated groups,
at 8, 10 and 12 weeks and later at monthly intervals by a stab in the comb or wing
web, using the homologous strain of the egg-propagated virus in the same concen-
tration as was used previously to vaccinate them. The vaccinated ones were re-
fractory to the challenge up to 12 months, while the controls reacted every time.
Among the 25 in-contacts in the second group, 2 died of causes other than pox, 7
developed visible lesions ; the rest were challenged at 8 weeks' age with the homo-
logous vaccine by the stab method. Three developed a weak reaction, while the rest
proved refractory (Table II).
EXPERIMENTAL
Vaccination with P.P.V.
Commercial pigeon scab virus from the Biological Products Division of the I. V.K.I.
was treated with anti-biotics to obtain a germ-free filtrate by the procedure previously
described by Rao et al. (loc. cit.) for inoculating eleven day-old embryonating eggs.
The virus grew readily on the chorio-allantoic membrane as evidenced by thick
oedematous plaques at the site of inoculation and scattered ones ventral to the
embryo. These were harvested on the fourth day of infection. Titration of the
virus in embryos gave the end points between 10 -6 and 10 -7 . In trial vaccinations,
neither in fowl nor pigeon was there metastatic or generalized spread from the site of
inoculation. Infected feather follicles were inflamed and distended with yellowish
material forming plugs. The vaccine was prepared by suspending the membranes
in 5 per cent proportion in 25 per cent buffered glycerine broth pH 74, as in the
case of the F.P. Vaccine.
Three groups, each of 100 wing-banded baby chicks two days old were raised in
three adjacent brooder pens, under the same care and management as in the
experiment with F.P.V. vaccination. All chicks under the experiment were weighed
at birth and then every week up to eight weeks. The first group received a stab
each in the web of the wing with the 5 per cent P.P.V. vaccine. The second lot was
similarly treated but 25 unvaccinated chicks of the same age were added to this
group to serve as in-contacts. The third lot of 100 served as controls. All
chicks were daily observed for "takes", secondary lesions and mortality. The
details are recorded in Tables III and IV.
TABLE III
Showing growth-rate of P. P. V. vaccinated and control chicks
Serial
No.
A
B
Group
Vaccinated . .
Control. . .
Vaccinated . .
Control . . .
No. of
chicks
100
50
100
50
Average body weight in grams
Day-old
31.8
32.3
30.4
28.2
2 weeks
72.4
75.6
76.8
84.2
4 weeks
170.4
168.2
174.2
176.5
6 weeks
280.5
285.4
290.2
288.4
8 weeks
425.2
420.4
426.4
425.8
194
STUDIES IN IMMUNIZATION AGAINST FOWL POX [Vol. XXVIII, Pt. IV,
TABLE IV
Showing results of vaccination with egg-adapted P. P. V. in day-old chicks
Group
Breed
W.L. (I)
R. I. R.
(II).
R. I. R.
W. L.
W. L.
No. of
chicks
100
100
50
(control)
50
25
(in-
contact
with II)
Vaccine
per cent
5
5
..
..
..
Takes
per cent
100
100
..
..
..
Second-
ary
lesions
per cent
..
..
..
..
..
Runts
per cent
..
..
..
..
..
Morta-
lity
per cent
10
11
10
..
0
Percentage refractory to
8 weeks
after
vaccina-
tion with
F. P. Virus
100
100
0
..
36
10 weeks
after
vaccina-
tion with
F. P. Virus
50
50
0
..
12 weeks
after
vaccina-
tion
10
20
0
..
OBSERVATIONS
"Takes", secondary lesions and immunity
In the two groups of baby chicks vaccinated with P.P.V. vaccine, there
was 100 per cent pronounced takes by the fifth day, which persisted up
to ten days, and no secondary lesions developed (Table IV). In the 25
in-contacts, there were no secondary lesions but 36 per cent were immune
to challenge at eight weeks. The vaccination had no significant influence
on the growth-rate (Table III) as compared with the controls. Ten vaccinated
chicks were selected at random from each of the two groups, tested weekly up to
eight weeks and were found refractory to the challenge. Subsequent to this period,
the immunity level however, fell rapidly to an average of 55 per cent by ten weeks,
and then to 15 per cent by the twelfth week.
This virus being benign produced no visible lesions, but was invasive, though to
a lesser extent, as it induced a silent immunity in 8 out of the 25 in-contacts which
withstood the challenge at eight weeks.
DISCUSSION
In the present series of observations it is seen that when egg-propagated fowl
pox virus was used for vaccination in day-olds, there was absence of abnormal
mortality, systemic reaction and that growth-rate was not retarded. Brandly
[1937] is of the opinion that the larger takes and active infection following the use
of scab virus were due to the contaminants present in the scab. Apparently this
leads one to conclude that the egg-propagated fowl pox virus would be a choice
prophylactic, especially for ensuring a better grade of immunity lasting for over
196
STUDIES IN IMMUNIZATION AGAINST FOWL POX [Vol. XXVIII, Pt. IV,
uniformly good ' takes', followed by immunity beyond 12 months in both con-
centrations of the virus. Other interesting observations were that neither significant
systemic reaction nor retardation of growth rate were noticed, as was reported by
previous workers who used the F. P. scab virus. However, there were secondary
lesions in F. P. vaccinated chicks, being 9 and 4 per cent in the two groups respec-
tively, nearly 90 per cent of the in-contacts developed immunity and were refractory
to challenge with F. P. virus. Further, 28 per cent of these in-contacts developed
lesions on the face and were mostly stunted in growth.
The P. P. vaccine was used in 5 per cent concentration of the membranes. In
this lot the systemic reactions and retardation of growth were absent, while the
vaccinates and in-contacts developed no secondary pox lesions. The immunity
in the vaccinates, however, broke down by ten weeks.
It appears from these observations that though F. P. virus may appear fairly
safe in healthy flocks of baby chicks, its use is not indicated where all the chicks held
in a brooder house cannot be vaccinated simultaneously.
Therefore, pigeon-pox vaccine is suggested for vaccination of day-old chicks
with 100 per cent safety under all conditions, followed at eight weeks by a stab with
F. P. V., just before placing the chicks in the open yards to continue the immunity
at a higher level.
ACKNOWLEDGEMENT
The authors thank Shri S. G. Iyer, Head of the Division of Poultry Research,
for his interest, encouragement and advice.
REFERENCES
Brandly, C. A. (1937). J. Amer. Vet. Med. Assoc., 90, 479-487
Cunningham, C. H. (1952). Diseases of Poultry. Biester and Sehwarte III Edition, p. 662
Dunn, R. C. and Sherwood, R. M. (1932). Poult. Sci., 12, 323
Doyle, T. M. and Minett, F. C. (1927). J. Comp. Path. and Therap., 40, 247
Glover, R. E. (1939). J. Comp. Path. & Therap., 52, 29-36
Haig, D. A. (1951). Onderstepoort J. 25, 17-29
Indian Veterinary Research Institute (Poultry Research Division) 1950. Unpublished work
Iyer, S. G., Rao, S. B. V. and Thakral, B. M. (1953). Proc. 40th Indian Sci. Congr., Part III, 51
Kamarov, A. and Kligler, I. J. (1936). J. Comp. Path, and Therap., 49, 90-95
Lubbehusen, R. E. and Ehlers, D. P. (1936). J. Amer. Vet. Med. Assoc, 80, 236-249
—,
and Beach, J. R. (1937). J. Amer. Vet. Med. Assoc., 90, 430-446
Rao, S. B. V., Thakral, B. M. and Ramnani, D. R. (1953). Indian Vet. J., 29, 387-395
A PRELIMINARY NOTE ON THE OCCURRENCE OF CLO-
STRIDIUM WELCHII TYPE D INFECTION IN SHEEP
IN INDIA
By P. R. NILAKANTAN and B. K. KATHRIA, Indian Veterinary Research Institute,
Mukteswar
[ Received for publication on January 15, 1958
Accepted for publication on May 27,
1958]
(With 5 Text Figures)
I NFECTIOUS enterotoxaemia of sheep is an acute toxaemic disease following
rapid multiplication of Clostridium welchii type D within the contents of the
small intestines. Even though this condition seems to have been in existence
for long, Gill [1927] seems to have been the first to study the disease in lambs in
New Zealand and give it the name of 'pulpy kidney disease '. Montgomerie and
Rowlands [1934] described a similar disease in Wales. In Australia the disease
appears to have been reported as early as 1915 when it was known as ' Beverley
disease'. After carrying out extensive research work Bennets [1932] was able
to establish the disease as caused by B. ovitoxicus.
Though the prevalence of the disease in sheep in India was suspected a few
years ago, attempts to investigate the disease were made only in recent years.
Chatupale [1948] proved the existence of the disease in the Dwaraka area. A visit
to a few of the organised sheep farms in the country by one of us (P. R. N.) and
examination of the available postmortem records revealed that sudden deaths in
well-conditioned sheep were not uncommon and often the only postmortem finding
in a number of cases was gastro-enteritis. This led to a systematic investigation
to ascertain the extent of prevalence of the disease in the various sheep-breeding
tracts in different states. A record is made here of the isolation of Cl. welchii type
D from a few outbreaks of the disease in some of the States of the Indian Union.
EXPERIMENTAL
In order to obtain material from a large number of cases of sheep suspected
to have died of enterotoxaemia for laboratory examination, instructions were sent
to the field veterinarians for collection and despatch of material to the laboratory
from suspected cases. Field investigations were also carried out in some of the
States, viz., Madras, Bombay and Bihar.
Material for laboratory examination consisted of intestinal contents preserved
in 0.5 per cent chloroform and pieces of intestines preserved in 50 per cent glycerine
saline. Often, material received was either insufficient or without any preservative
or it was collected from carcasses of sheep long after death, with the result that
not all specimens received in the laboratory were fit for examination.
197
78 AR/58
6
198
CLOSTRIDIUM WELCHII TYPE D INFECTION IN SHEEP [Vol. XXVIII, Pt. IV,
Direct smear examination
Direct smears were made from the intestinal contents as well as from the intes-
tinal mucous membrane and stained by Gram's method. Smears from typical
cases of infectious enterotoxaemia revealed large number of Gram-positive, short,
stumpy, rod-shaped organisms.
Examination of the intestinal contents for the presence of toxins
Intestinal contents, when available in sufficient quantity, were first centrifuged
at 3000 r.p.m. for 30 minutes and the supernatant tested for toxicity in mice and
rabbits. Usually mice were inoculated with 0.3 ml. and 0.6 ml. doses intravenously
and rabbits were given 0.2 ml. intradermally. Presence of toxins was revealed by
death of the mice, often with convulsive and paralytic symptoms, in a few minutes
to 12 to 15 hours after injection and by typical dermonecrotic lesions which deve-
loped at the site of inoculation in rabbits. If the intestinal contents proved toxic,
neutralization tests with antitoxic sera of different types of Cl. welchii were carried
out to determine the type of toxic factors involved.
Isolation of organism
Attempts to isolate Cl. welchii were made from intestinal contents as well as
washed pieces of intestines received for examination at the laboratory. Usually,
cooked meat medium was inoculated with a small quantity of intestinal contents
or a suspension of pieces of intestines in normal saline solution and incubated at
37°C. The cultures were periodically examined. When gas production was dis-
cernible, subculture was made in another tube of cooked meat medium, which
again was incubated till gas production was noticed. Culture from the second tube
was plated on blood agar plates which were incubated in an anaerobic jar for 24
to 48 hours. Typical colonies resembling those of Cl. welchii were picked up and
subcultured. Purification of the culture was effected by repeated plating and
picking up of single colonies in cooked meat medium. Every time a transfer was
made in this manner, smears of the culture were examined to check the morphology
of the organism. In the initial stages, tubes of litmus milk were also inoculated
with the first subculture to see if the organism produced the stormy fermentation,
which is a characteristic of Cl. welchii and to see whether its development would
furnish early evidence of the presence of the organism in the culture.
Typing of the strain
Each strain of Cl. welchii isolated from intestines or intestinal contents, after
purification, was studied for its morphology, staining and cultural characters on
blood agar plates and in shake cultures, biochemical reactions, viz., fermentation
of carbohydrates like glucose, lactose, maltose, mannite, sucrose and salicin, and
action on litmus milk and for the ability to liquefy gelatin. After establishing
the identity of the cultures on the basis of the above tests, further typing was done
by producing toxins and carrying out neutralization tests with antitoxic sera obtain-
ed from Messrs Burroughs Wellcome and Company.