A practical method of active case finding and epidemiological assessment: its origin and application in the leprosy control project in Indonesia.

Random sample surveys in the past have revealed high estimated against low registered prevalences for leprosy in several parts of Indonesia. A pilot project showed that the problem of cases that had not yet been detected could not be solved without the active participation of the local authorities, who proved able to overcome the stigma and to convince potential patients to go for examination and treatment. The pilot project was based on the principle of what are called exploration surveys, which were introduced by Sitanala in Indonesia in 1931. The Indonesian government decided to reintroduce these surveys in 1977 under the name of chase or trace surveys. They are carried out within the framework of the leprosy workers' routine duties and no additional expenses are incurred. Since then, thousands of patients of all types and with long case histories have been detected and brought under treatment. Without this "push" it is fair to assume that many would never have sought treatment voluntarily. In view of the experience in Indonesia, one wonders whether leprosy can be eliminated without emphasizing the importance of active case finding, especially in areas in which the disease is still highly endemic. Chase surveys also provide rough information about the local leprosy situation. Although of great value, they are not, in high-endemic regions, an alternative to random sample surveys which reveal, besides a wealth of additional information, the possible unknown sources of infection.