Time trends in the analysis of incidence rate of leprosy among household contacts.

Analysis of time trends in the Incidence Rates among 9.598 household contacts of 1,614 primary cases of leprosy, showed that the incidence rates (IR) remained high even 10 years after treatment was started in the Primary Case. The IR during the 1st year of follow-up was 3.8 per 1000 person years of risk (PYR) and the IR was 3 per 1000 PYR after 10 or more years of follow-up. The significance of these findings in relationship to the Epidemiology of leprosy among household contacts in an endemic area for leprosy is discussed.