Epidemiological Shifts in Visceral Leishmaniasis Incidence, Relapse, and Mortality in Brazil, 2007-2023: Analysis...

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.

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.

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).

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.