Leprosy is a
neglected tropical disease predominately affecting poor and marginalized populations. To test the hypothesis that poverty-alleviating policies might be associated with reduced
leprosy incidence, we evaluated the association between the Brazilian Bolsa Familia (
BFP) conditional cash transfer program and new
leprosy case detection using linked records from 12,949,730 families in the 100 Million Brazilian Cohort (2007-2014). After propensity score matching
BFP beneficiary to nonbeneficiary families, we used Mantel-Haenszel tests and Poisson regressions to estimate incidence rate ratios for new
leprosy case detection and secondary endpoints related to operational classification and
leprosy-associated disabilities at diagnosis. Overall, cumulative
leprosy incidence was 17.4/100,000 person-years at risk (95% CI: 17.1, 17.7) and markedly higher in "priority" (high-burden) versus "nonpriority" (low-burden) municipalities (22.8/100,000 person-years at risk, 95% confidence interval (CI): 22.2, 23.3, compared with 14.3/100,000 person-years at risk, 95% CI: 14.0, 14.7). After matching,
BFP participation was not associated with
leprosy incidence overall (incidence rate ratio (
IRR)Poisson = 0.97, 95% CI: 0.90, 1.04) but was associated with lower
leprosy incidence when restricted to families living in high-burden municipalities (IRRPoisson = 0.86, 95% CI: 0.77, 0.96). In high-burden municipalities, the association was particularly pronounced for paucibacillary cases (IRRPoisson = 0.82, 95% CI: 0.68, 0.98) and cases with
leprosy-associated disabilities (IRRPoisson = 0.79, 95% CI: 0.65, 0.97). These findings provide policy-relevant evidence that social policies might contribute to ongoing
leprosy control efforts in high-burden communities.