A trend analysis is presented of all newly detected leprosy cases over an
1 8-year period (1979- 1 996) in a highly leprosy endemic area of Bangladesh. A total
of 23,678 new cases were registered, with an average of 860 new cases per year in the
first 12 years, and increasing to around 3000 in 1 996. The male : female (M : F) ratio
decreased from 2·3 to 1 -4. The proportions of newly detected cases with MB leprosy
and of newly detected cases with any disability decreased over time. These reductions
were more marked in the higher age groups of both sexes. The reduction in disability
was primarily attributable to a decline in grade 2 disability. New case detection rates
(NCDR) of all leprosy patients per 1 0,000 general population increased for males
from 3 to 6; and for females from I to 4, while the NCDR of MB leprosy decreased in
males from 1 ·4 to 0,6, and in females fluctuated around 0-45 . The NCDRs of leprosy
patients with disabilities showed an initial decrease in the first period, especially in
males, but later showed an increase. The NCDR of males with disability was about
twice as high as that of females. Finally, female NCDRs in the ages between 15 and
30 were low by comparison with the male NCDRs at the same time. This may be due
to the sociocultural characteristics of the Bangladeshi society, with gender differences
in exposure, health seeking behaviour and opportunities for case detection. Operational
changes in the control programme have contributed to the changed profile of newly
detected cases. This study shows that the application of general population statistics
is essential for understanding the dynamics in leprosy control programmes under
changing operational conditions. Combining case detection figures with such statistics
helps to identify population groups that are possibly not benefiting sufficiently
from the services provided, and to clarify the dynamics in control programmes and
the future trends and programme requirements.