RESUMO
A review is made of some previous studies on leprosy incidence among contacts, particularly children born of patients in leprosaria. Fluctuations in incidence rate constantly occur, even in the same area. The changes may be due to a number of factor, including different methods of study and varying pathogenic potential which involve susceptibility and resistance among the contacts and intensity and duration of exposure to m.leprae in the enviromment. The incidence is studied in detail in l206 childreen, nearly all of them born in the Culion Sanatorium, and observed closely by the same continuing group of workers for from l year to 20 years during the period l948 through 1967. Most of the children had been separated at birth and brought up in a nursey where they were given lepromin, BCG, or their combinations before being returned tio theier parent at ages of from 1 year to a little over 6 years. a still smaller group among the unisolated children was also given injections