152

Report on Kála-ázar.

     This group of villages is situated in a very out-of-the
way part of the district, and it will be noticed that in some
of them the disease was brought from a distance by persons
coming to live in them after having contracted the fever in
one or other of the larger and earlier infected places, while
others are infected from the neighbouring villages into which
the disease was first introduced from some little distance.
This is the usual way in which the disease travels, and the
very irregular distribution of the affected villages in any
part of a district which is just being invaded by the epidemic,
is thus accounted for. Subsequently, when once the disease
has broken out in a few villages in any place, the frequent
inter-communication between the affected and unaffected
villages ensures all of them being attacked sooner or later,
except in the rare cases where the villagers recognise in
time the infectiousness of the disease, and cut off all com-
munication with those who have got it, and then a part of
a village may escape, although it is present in the rest of the
same village from which it is only separated by two or three
hundred yards of rice-fields. Another common mode of
conveyance of the disease is through the custom, amounting
almost to a religious duty, of the people visiting sick relatives
in the neighbouring villages, which very often means eating
and sleeping with them. Again, I have met with instances in
which the disease was spread by persons who are actually
suffering from it, and who have lost all near relatives on whom
they were dependent, being taken into the houses of other
relations in different and previously unaffected villages. In
these and many other ways the disease, when once it has
been introduced into a district, spreads slowly and surely, but
in a very irregular manner until almost every village suffers.

     The day's experience which I have detailed above, taken
with facts that had previously come to my knowledge, quite
convinced me of the communicability of the disease; but
as this is a most important and crucial point, both from
the theoretical and practical points of view, I subsequently