Should household contact examination in a low endemic situation of leprosy continue?

After more than 40 yrs of effort, leprosy is finally under control in Shandong province with only 50 to 70 new cases detected each year in the past 10 yrs. Contact examination is still compulsory and household contacts will be followed for 5 to 10 yrs, as directed by the guidelines of the national leprosy control program. In order to assess the value of contact examination in terms of case finding in a low endemic situation of leprosy in Shandong, we analyzed the data regarding all newly diagnosed leprosy cases in the past 11 yrs using the data abstracted from the national leprosy recording and reporting system, and a questionnaire-based survey to see how many incident leprosy cases would be detected if we followed the policy for contact examination of leprosy in Shandong. The results showed that 252 out of 547 leprosy cases diagnosed from 1990 to 2001 reported they had contact with different categories of primary leprosy cases. Among them, 90 cases had household primary leprosy cases. The mean incubation of the 252 index cases was 23 yrs. If we followed the national policy for contact tracing for 5 or 10 yrs, then only 12 (13.3%) and 10 (11.1%) of the 90 cases whose source of infection was household contacts would have been detected, respectively. Therefore, other approaches should be sought, in order to detect the few incident leprosy cases as early as possible in such a low endemic situation of leprosy in Shandong.