Leprosy physical disabilities in the 100 Million Brazilian Cohort

Abstract

Background Leprosy continues to be an important cause of physical disability in endemic countries such as Brazil. Knowledge of determinants of these events may lead to better control measures, as targeted interventions may mitigate their impact on affected individuals. This study investigated such determinants among the most vulnerable portion of the Brazilian population. Methods A large cohort was built from secondary data originated from a national registry of applicants to social benefit programs, spanning the period 2001 to 2015 and including over 114 million individuals. Data were linked to the Leprosy disease notification system utilizing data from 2007 until 2014. Descriptive and bivariate analyses lead to the multivariate analysis using a multinomial logistic regression model with cluster-robust standard errors. Associations were reported as Odds Ratios with their respective 95% confidence intervals Results 21,565 new leprosy cases were identified among the original cohort members from the study period. Most of the cases (63.1%) had grade zero disability. Grades 1 and 2 represented 21 and 6%, respectively. Factors associated with increasing odds of grades 1 and 2 disability were age over 15 years old (ORs 2,39 and 1,95 respectively), having less schooling (with a clear dose response effect), being a multibacillary patient (ORs 3,5 and 8,22). Protective factors for both grades were being female (ORs 0,81 and 0,61) and living in a high incidence municipality (ORs 0,85 and 0,65). Conclusions Worse socioeconomic conditions might act as barriers to early diagnosis, which increases the risk of developing physical disabilities. Early diagnosis is paramount to decrease the incidence of leprosy-related disability, and our findings point to the need for strengthening these actions in non-endemic areas, where cases may be missed when presented at early stages in disease progression. In addition, data linkage proved to be useful in generating evidence for improving policy target at leprosy control in Brazil.