Protective efficacy of BCG against leprosy in Sao Paulo

ABSTRACT

The case-control study reported here evaluated the protective effect of BCG vacine against leprosy in Sao Paulo, Brazil. Seventy-eight patients under age 16 who had been diagnosed as having leprosy (cases) and 385 healthy individuals (controls) were selected and matched by sex, age, place of residence, and type of exposure to leprosy (intradomiciliary or extradomiciliary). The cases were draw from an active patient registry and from a group of new leprosy cases treated at 50 health centers in the cities of Bauru and Ribeirao Preto in the state of Sao Paulo. In order to estimate the protective effect of BCG, the prevalences of BCG scars in cases and controls were compared. The presence of one or more scars was associated with an estimated protective efficacy of 90 percent (95 percent confidence interval 78 percent to 96 percent). Stratified analysis by age group, sex, socieconomic level, and clinical form of the disease revealed no significant differences in the protection provided by the vaccine, However, it seems clear that more data will be needed in order to accurately assess the true relevance of BCG for leprosy control programs (AU)