Epidemiological Shifts in Visceral Leishmaniasis Incidence, Relapse, and Mortality in Brazil, 2007-2023: Analysis Using the National Notifiable Diseases Information System.

Background: Brazil accounts for >90% of visceral leishmaniasis (VL) cases reported in South America. VL is a notifiable disease in Brazil and patient records are captured in the Sistema de Informação de Agravos de Notificação (SINAN) database. Methods: We reviewed 55 723 patient records from the SINAN system (2007-2023) to present temporal trends in patient demographics, drug regimens administered, and treatment outcomes. Disease incidence was modeled using a negative binomial regression, and predictors of mortality were assessed using logistic regression. Results: The VL incidence declined 6% annually (incidence rate ratio, 0.94 [95% confidence interval {CI}, 0.92-0.97]), primarily during 2019-2023. The median age at presentation was 10 years (interquartile range [IQR], 2-33 years) in 2007 and 32 years (IQR, 7-48 years) in 2023. The proportion of relapse at presentation also increased over time; compared to 2007-2009, the odds of relapse during 2019-2023 were 2.10-fold higher (95% CI, 1.87-2.37) adjusted for human immunodeficiency virus status. The use of liposomal amphotericin B increased markedly from 6.1% during 2007-2009 to 38.1% during 2019-2023, while antimony use declined from 68.0% to 32.7% over the same period. Following treatment, death from VL was highest among infants (<1y) (425/4125 [10.3%]) and those >50 years of age (1471/7615 [19.3%]), compared to the other age groups (3.5%, 2.2%, and 8.0% among ages ≥1 to <5, ≥5 to <15, and ≥15 to ≤50 years, respectively). Conclusions: The shift toward older patients and increased relapse at presentation indicates a major change in disease epidemiology in Brazil. These findings highlight the need for prioritizing interventions for older and relapsing patients.