Background
Chagas disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, primarily transmitted by infected bugs, but also through contaminated food, transfusions, congenital transmission, and organ transplantation. Chagas disease has acute and chronic phases; the chronic phase can occur decades after infection, leading to complications such as heart failure, arrhythmias, and megaviscera. Accurate mortality and morbidity estimates are hindered by under-reporting and misclassification. Comprehensive and updated estimates are needed to improve global assessments of Chagas disease burden. We aim to provide a comprehensive description of global and regional burden of Chagas disease and its trends from 1990 to 2023.
Methods
In this systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2023, we produced estimates of Chagas disease deaths, years of life lost (YLLs), prevalence, incidence, years lived with disability (YLDs), and disability-adjusted life-years (DALYs) for 204 countries and territories from 1990 to 2023 by age and sex. The GBD 2023 estimates supersede previous estimates for all years. For mortality estimates, we fit a cause of death ensemble model to vital registration data. For non-fatal estimates in endemic locations, we did a systematic review of seroprevalence data, defining a confirmed case as a confirmed diagnosis of T cruzi infection by two different positive tests (or a single ELISA or immunochromatographic test). After adjustment for the population at risk, we used a Bayesian compartmental model (DisMod-MR) to produce estimates. For non-endemic locations, we estimated prevalence on the basis of migration patterns and estimated prevalence from endemic countries. Prevalence of acute and chronic sequelae and corresponding disability weights were used to calculate YLDs.
Findings
We estimated 10·5 million (95% uncertainty interval 9·4-11·7) Chagas disease prevalent cases in 2023 globally, a 16·1% (12·6-19·2) decrease compared with 1990. The global age-standardised Chagas disease prevalence rate declined by 55·0% (53·8-56·1) from 1990 to 2023, with rates decreasing across all endemic regions. The highest age-standardised Chagas disease prevalence rates in 2023 were in southern Latin America (2485·9 [2249·6-2707·7] per 100 000) and Andean Latin America (2313·8 [2093·7-2570·1] per 100 000). Non-endemic regions experienced notable increases in prevalence due to migration from endemic countries. The age distribution of cases shifted over time, peaking at older ages in 2023 (between age 45 years and 65 years) compared with 1990 (30-45 years). In 2023, there were 352 000 (308 000-398 000) new cases of Chagas disease globally, with the age-standardised rate decreasing by 55·1% (53·4-56·6) since 1990. There were 8420 (7480-9360) deaths globally in 2023. Age-standardised mortality decreased by 72·5% (68·9-75·4) globally from 1990 to 2023. In 2023, the highest age-standardised mortality rates were in tropical Latin America (2·2 [1·9-2·4] per 100 000) and Andean Latin America (0·92 [0·70-1·2] per 100 000).
Interpretation
The GBD 2023 Chagas disease estimates are notably higher than previous GBD estimates, reflecting additional data and methodological improvements, and those published by the Pan American Health Organization. Nevertheless, these updated estimates show decreasing prevalence and incidence in endemic countries, highlighting the importance of socioeconomic development, housing conditions, and vector-control policies. Conversely, the increase in prevalence in non-endemic countries, mainly due to migration, requires new strategies for screening, early recognition, and access to care. Although the marked decrease in mortality and YLLs might be due to better access to care at different levels, the shift in age distribution highlights the importance of preparing and funding health systems for caring for older populations with advanced sequelae. Finally, the continuous refinement of data-source quality, including adequate coding and classification, is crucial for the accuracy of global estimates, which can ultimately drive health and social policies.
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