Outcome of late healthy household contact examinations in leprosy-affected households in Bangladesh

Objective: Though household contact examinations are a recognised method of active case finding in leprosy control programmes, there is little evidence to determine appropriate duration of annual surveillance, when weighing likely benefit against inconvenience to households and investment in health staff time. Considering this, the aim was to establish the temporal pattern of new case finding through a crosssectional survey, by examining year-wise cohorts of individuals from the households of leprosy cases diagnosed at different times in the past. Results: For multi-bacillary (MB) index cases’ contacts, the new case detection rate (NCDR) falls only after five years from diagnosis of index case. For contacts of paucibacillary (PB) cases, the lower initial NCDR remains well below that for MB index cases. Conclusions: The low rates of new case detection demonstrated in this study would not justify greatly prolonged active surveillance, but household contacts should be warned of their continuing risk.