EMERGENCIES IN PUBLIC HEALTH OF EPIDEMIOLOGICAL AND TECHNOLOGICAL CAUSES: EFFECTS ON THE DYNAMICS OF HEPATITIS A TRANSMISSION IN BRAZIL (2014–2023)

To analyze the effects of public health emergencies ‒ such as the Brumadinho dam collapse (2019) and the COVID-19 pandemic (2020–2023) ‒ on the dynamics of hepatitis A transmission in Brazil, with a focus on Minas Gerais and municipalities located in affected health regions. Ecological study with time-series analysis (2014–2023) of hepatitis A incidence rates per 100,000 inhabitants, using data from SINAN and IBGE. Analyses were stratified by Federative Units, Minas Gerais, and groups of case and control municipalities. Periods were classified as pre-emergencies (2014–2018) and post-emergencies (2019–2023). A downward trend in hepatitis A rates was observed in Brazil between 2014 and 2021, with stabilization at low levels during the COVID-19 pandemic. The reduction was more pronounced after 2017, reflecting the expansion of childhood vaccination and the effect of sanitary measures implemented during the period. Minas Gerais maintained consistently low incidence, without relevant fluctuations after the dam collapse. Between 2022 and 2023, an increase in rates was observed in Rio Grande do Sul (0.86 → 3.24), Santa Catarina (0.22 → 3.09), Rio de Janeiro (0.85 → 1.30), São Paulo (0.52 → 1.94), and Roraima (0.16 → 2.36). These increases coincide with the end of the Public Health Emergency of National Importance (ESPIN) in May 2022, potentially indicating re-exposure to environmental risks, a decline in vaccination coverage, or reduced surveillance and prevention actions. In case municipalities, rates decreased from 0.37 (2014) to 0.09 (2016), rose again in 2018–2019 (0.19 and 0.37), and fell to zero in 2022. Control municipalities showed higher values at the beginning of the series (0.76 in 2014), with oscillations until 2018 and subsequent decline, registering a slight increase in 2022 (0.25). The absence of data for 2021 and 2023 for these groups limits full interpretation, but the observed pattern suggests a general downward trend with punctual fluctuations in critical years. The national downward trend in hepatitis A rates appears to have been maintained, even in the face of the analyzed emergencies. However, punctual increases in some states after the end of the ESPIN indicate the importance of maintaining environmental surveillance and vaccination actions. In municipalities affected by the dam collapse, no consistent increase in incidence was observed, reinforcing the relevance of local mitigation strategies and continuous monitoring in public health emergency contexts.