Changing epidemiological pattern of leprosy in rural Chhattisgarh.

The study presents findings of a retrospective cohort analysis of 2972 new cases registered between 1 January 1987 and 31 December 2001 in the rural field practice area of RLTRI, Raipur. An analysis was carried out with the objective of describing the epidemiological pattern of leprosy in the preceding 15 years. The patients in the study were also followed up prospectively till December 2003 to record any development of relapse or reactions. Data collected were grouped into three time-blocks and analysed at five-yearly intervals. Epidemiological indicators in different periods were also compared. 2972 new cases were included in the analysis; of these, 15.6% were registered in time-block 1, 20.9% in time-block 2 and 63.5 % in time-block 3. The P/D ratio, which was 8.5 in 1986 declined to 6.6 in 1991, 1.3 in 1996 and 0.4 in 2001 after which it rose marginally to 0.8 in December 2002. The proportion of MB cases showed a rise of 15.3% in 1991, 25.1% in 1996 and 28.7% in 2001. The mean age at registration showed a significant decline during different time periods from 35.2 +/- 16.9 in time-block I to 28.9 +/- 15.9 in time-block 3. The proportion of grade II deformity was 3.2% in time-block 1; it rose to 6.3% in time-block 2 and 5.9% in time-block 3. The proportion of cases completing treatment was 28.2% and 17.6% for MB and PB groups respectively in time-block 1, rose to 69.9% and 77.0% in the 2nd, and 74.9% and 81.6% in the 3rd. The proportion of relapse also came down markedly in time-blocks 2 and 3. The median duration of treatment was 28.0 months in time-block 1, came down to 9.0 months in time-block 2 and 7.0 months in time-block 3 following the introduction of MDT. The proportion of child cases and reaction rates showed a rise in time-blocks 2 and 3.