Trends in case detection influenced by leprosy elimination campaigns in certain areas of China

LECs were carried out from 1998 to 2000 in eight counties of west China. The number of cases detected during the year of LECs was much higher than that detected by routine methods before the year of the LEC. However, the annual number of cases detected during the year after the LEC showed different patterns. One pattern is that the number of new cases detected in the year after the LEC declined to the level similar to that before the year of the LEC. The second pattern is that the number of new cases detected in the year after the LEC declined steeply to less than that detected before the year of the LEC. Following peak case-detection during the year of the LEC, a gradual decrease in the number of new cases was observed in the subsequent years. The repeat LEC brought a weakly rebounding peak case-detection during the year following the first LEC carried out 3 years earlier. The operational, epidemiological and technical factors influencing the trends of case-detection during the LECs are discussed.