31

Room Number.
Number of Inmates and whether inoculated.
Number of
Attacks.
Deaths.
8
3 Not inoculated
2 Inoculated
9
3 Not inoculated
2
1
1 Inoculated
10
4 Not inoculated
1 Inoculated

The inhabitants of rooms 1 and 10 which adjoined one another at one end,
but did not communicate directly with any infected room, may be deducted
from the above, as no cases of disease occurred among them.
This leaves 8 rooms to be taken into account, and these were inhabited by
53 persons of whom 32 were not inoculated and 21 had been thus operated on.
Each of the rooms contained a mixed population of inoculated and not inocu-
lated persons-
The 32 not inoculated had 19 cases with 12 deaths.
The 21 inoculated had 1 case with no death.
If the inoculated had suffered to the same extent as those not inoculated,
they ought to have had 12 cases with 8 deaths, but they only had 1 case which
recovered. This is equal to a reduction of 91.7 per-cent. in the case of attacks
in favour of the inoculated.
The fact that 21 of the inhabitants were away at work all day, and only
returned to sleep at night, makes no difference between the two groups, for on
enquiry it was found that no cases of plague had occurred in the various places
where these people had worked. The infection, therefore, was localised in the
chawl, and no circumstance existed that in any way favoured the one group
over the other.
The following statement brings this out clearly :-
Those staying at home all { 16 Not inoculated had 9 cases.
day. { 16 Inoculated had 1 case.
Those going out to work { 16 Not inoculated had 10 cases.
during the day. { 5 Inoculated had 0 cases.
The uninoculated persons being equally divided between those who stayed
at home and those who worked outside, and the two groups returning almost
the same percentage of cases indicates that the source of infection was common
to both, and must therefore have been in the dwelling house itself.
The 53 inhabitants of the above 8 rooms were distributed by age as follows:-
Up to 10 years of age
11 Not inoculated had 7 cases with 2 deaths.
4 Inoculated had 0 cases with 0 deaths.
From 11 to 50 years of age
20 Not inoculated had 12 cases with 10 deaths.
17 Inoculated had 1 case with 0 death.
Above 50 years of age
1 Not inoculated had 0 case with 0 death.
0 Inoculated had 0 case with 0 death.
B 42 +