Global, regional, and national burden of Visceral leishmaniasis, 1990-2021: findings from the global burden of disease study 2021

Abstract

Background: Leishmaniasis is a vector-borne parasitic disease caused by protozoa of the Leishmania genus; it is transmitted through the bites of infected phlebotomine sandflies. Clinically, it manifests in three primary forms: cutaneous, mucocutaneous, and visceral leishmaniasis (VL). Among these, VL represents the most severe form, characterized by high morbidity and mortality, and poses a considerable public health burden, particularly in endemic regions. This study utilizes data from the Global Burden of Disease (GBD) study 2021 to conduct a comprehensive analysis of the global epidemiological trends and burden of VL from 1990 to 2021, aiming to generate evidence-based insights to inform prevention and control strategies.

Methods: Using GBD 2021 data, this study examined trends in the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of VL across 204 countries and territories, stratified by age, sex, and sociodemographic index (SDI) levels. Average annual percent change (AAPC) was calculated to describe trends in age-standardized rates and indicator counts from 1990 to 2021.

Results: From 1990 to 2021, the global age-standardized incidence rate (ASIR; AAPC = -0.25, 95% confidence interval (CI) -0.25, -0.24), age-standardized prevalence rate (ASPR; AAPC = -0.06, 95% CI -0.06, -0.05), age-standardized mortality rate (ASMR; AAPC = -0.03, 95% CI -0.04, -0.02), and DALY rate (AAPC = -2.38, 95% CI -2.44, -2.33) for VL all showed a declining trend. The ASMR was highest among children under 5 years old and decreased progressively with age. VL remains a critical and under-recognized tropical disease in Latin America, the Middle East, Africa, and South Asia.

Conclusions: VL disproportionately affects males and presents the highest risk in children under 5 years. Enhanced global collaboration in infectious disease control, with a focus on regions such as Latin America, Africa, the Middle East, and South Asia, is essential to further reduce the burden of VL.

Keywords: Age-standardized rates; Global burden of disease; Visceral leishmaniasis.

Fig. 1

The changing trends of age-standardized rates for visceral leishmaniasis were analyzed among the global population and five SDI regions (A ASIR; B ASPR; C ASMR; D age-standardized DALY rate) ASIR age-standardized incidence rate, ASMR age-standardized mortality rate, ASPR age-standardized prevalence rate, DALYs disability-adjusted life years, SDI sociodemographic index

Fig. 1

The changing trends of age-standardized rates for visceral leishmaniasis were analyzed among the global population and five SDI regions (A ASIR; B ASPR; C ASMR; D age-standardized DALY rate) ASIR age-standardized incidence rate, ASMR age-standardized mortality rate, ASPR age-standardized prevalence rate, DALYs disability-adjusted life years, SDI sociodemographic index

Fig. 2

The specific rate of VL showed notable differences across age–gender distributions in 2021 year (A incidence; B prevalence; C mortality; D DALYs); each figure depicts the uncertainty intervals for sex-specific rates, with the blue-shaded area representing males and the red-shaded area representing females; DALYs disability-adjusted life years, UI uncertainty interval, VL visceral leishmaniasis

Fig. 2

The specific rate of VL showed notable differences across age–gender distributions in 2021 year (A incidence; B prevalence; C mortality; D DALYs); each figure depicts the uncertainty intervals for sex-specific rates, with the blue-shaded area representing males and the red-shaded area representing females; DALYs disability-adjusted life years, UI uncertainty interval, VL visceral leishmaniasis

Fig. 3

The association between the age-standardized rate of VL and the SDI in the global population and 21 geographical regions from 1990 to 2021(A ASIR; B ASPR; C ASMR; D age-standardized DALYs); in each of the four figures, the black curve depicts the relationship between the rate and SDI, with the shaded area denoting the 95% confidence interval; ASIR age-standardized incidence rate, ASMR age-standardized mortality rate, ASPR age-standardized prevalence rate, DALYs disability-adjusted life years, SDI sociodemographic index, UI uncertainty interval. VL visceral leishmaniasis

Fig. 3

The association between the age-standardized rate of VL and the SDI in the global population and 21 geographical regions from 1990 to 2021(A ASIR; B ASPR; C ASMR; D age-standardized DALYs); in each of the four figures, the black curve depicts the relationship between the rate and SDI, with the shaded area denoting the 95% confidence interval; ASIR age-standardized incidence rate, ASMR age-standardized mortality rate, ASPR age-standardized prevalence rate, DALYs disability-adjusted life years, SDI sociodemographic index, UI uncertainty interval. VL visceral leishmaniasis