288
Bovine Contagious Pleuropneumonia in Assam
summer is shorter still. Due to heavy rainfall and
annual floods, large areas of low-lying land are
inundated, and several areas remain waterlogged
and are open for grazing during the winter only.
Nature of the epidemic and locality affected
Outbreaks of bovine contagious pleuropneu-
monia have been observed only in the Assam
valley and that too in certain localities lying on
either bank of the Brahamaputra and its major
tributaries. In the map of Assam (Fig. 1) the
affected localities of bovine contagious pleuro-
pneumonia are shown.
Particulars regarding the outbreaks are given
in Table I.
TABLE I
Serial
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
Locality of the outbreak
Deosiri grazing area
Sobanshah village
Patakata char, an island in
the bed of the Brahmaputra
Bordangi forest reserve
Barchandra village
Patabari forest reserve
Majuly area
Kokilamori village
Kadamialgaon village
Lowly village
Dikhowmukh area
Tarabari village
Kamalabari village
Name of
district
Goalpara
Kamrup
Goalpara
Goalpara
Kamrup
Goalpara
Sibsagar
Sibsagar
Lakhimpur
Kamrup
Sibsagar
Darrang
Sibsagar
Date of
prevalence
January 1940
June 1940
August 1940
September
1940
September
1940
January
1941
May 1941
October 1941
January 1942
February 1942
March 1942
May 1942
June 1942
Data collected in these outbreaks as well as
information obtained from other sources indicate
that there is no particular season for the incidence
of the disease. However, some of the outbreaks
have been observed about a week or two after
heavy rains. There is also evidence to suggest
the possibility of endemic and soil-borne nature
of the infection in some of the outbreaks. The
disease usually breaks out in the same area or in its
neighbourhood from time to time. However,
full information regarding periodical nature of
its incidence could not be obtained, but there is
reliable evidence of its spread in a slow and steady
manner.
The epidemic is characteristic in its slow and
progressive course. In the early stage of the out-
break, deaths are not so very frequent or in large
numbers, with the result that one might overlook
the existence of the infection. The slow and
insidious nature of its course in the herds usually
extends from four to six months and occasionally
even to a period of about a year.
Cattle of both sexes and of all ages are equally
susceptible. The mortality amongst the affected
cattle ranged from 60 to 70 per cent. Cattle are
the primary victims, and buffaloes contract
the infection, though rarely, at the later stage of
the epidemic. In certain outbreaks, no death
was observed among buffaloes, in spite of the fact
that they were living in the infected locality.
Goats and sheep, howsoever intimately in contact
with the infected cattle, seem to be resistant to
natural infection.
The disease has been found prevalent in districts
on either bank of the Brahamaputra. In the affect-
ed areas, there are some differences in local fea-
tures and in the method of maintenance of cattle.
To have a correct appreciation of these factors,
it is proposed to describe the outbreaks in the three
districts—one outbreak in each district.
Outbreak in Goalpara district
Investigation into bovine contagious pleuro-
pneumonia was carried out in January 1940 and
in subsequent years in Goalpara district. The
first outbreak was received from Nijalaguri
khuti in Deosiri grazing area, which is more or
less a forest tract about 25 miles north of the
Brahamaputra river near the foot of the Bhutan
Hills and is situated comparatively on a higher
level on the western bank of the river Aie, a
tributary to the Brahamaputra. Large numbers of
cattle are maintained in this area for grazing and
there were about a dozen khutis. In Nijalaguri
khuti there were about 220 head of cattle but no
buffaloes. In the course of about two months
there were 46 attacks resulting in 30 deaths.
Cattle movement, particularly for sale, is com-
mon. Villagers usually purchase cattle from
khutis. Occasionally, movement of cattle bet-
ween khutis by way of sale or exchange is also
reported. In the grazing area, certain portions
have come under cultivation where villages or
bustis have grown. In an attempt to trace the
source of infection, it was ascertained that the