Hideharu Hagiya, Maharu Hiroi, Natsuho Horiba, Ayaka Ogawa, Sayoko Nishimura, Michio Yamamoto, Takahiro Niimura, Yuka Osaki, Ko Harada, Yoshito Nishimura, Yoshito Zamami, Toshihiro Koyama
Globally, the leprosy-associated disease burden has declined over the last three decades, including among children and adolescents in endemic regions.
BACKGROUND: Despite substantial progress in reducing incidence, considerable challenges to global leprosy elimination persist. This study sought to elucidate longitudinal trends in the global leprosy-associated disease burden through multiple stratifications.
METHODS: Using data from the Global Burden of Disease Study, we analyzed the age-standardized incidence rate (ASIR) and Disability-Adjusted Life Years (DALYs) rate (ASDR) per 100,000 population for leprosy, stratified by geography (seven super-regions in the GBD regional classification), age (focusing on the pediatric population), income level (World Bank classification), and Healthcare Access and Quality (HAQ) index. The ICD codes used to identify leprosy were A30-A30.9 and B92 for ICD-10, and 030-030.9 and V74.2 for ICD-9. A locally weighted regression (LOESS) model was applied to estimate long-term trends, and joinpoint regression analysis was used to identify significant trend change points.
RESULTS: Data from 204 countries were included in the analysis. From 1990-2021, favorable decreases in the LOESS estimates of ASIR were observed in South Asia (6.307-1.321), followed by Sub-Saharan Africa (2.789-0.808) and Latin America and the Caribbean (2.605-1.506), with a global average annual percent change (AAPC) of -3.301. AAPCs of ASDR also showed significant declining trends across all geographic regions, with a global AAPC of -2.638. Among children and adolescents, global AAPCs of ASIR and ASDR also decreased favorably. By income level, lower-middle- and low-income country groups demonstrated consistent declining trends in ASIR and ASDR. Strong correlations between ASIR and ASDR and the HAQ index were observed in each country at the beginning and the end of the study period.
CONCLUSIONS: Globally, the leprosy-associated disease burden has declined over the last three decades, including among children and adolescents in endemic regions.