Spatio-temporal analysis of hepatitis A epidemiology in Morocco from 2018 to 2025

The impact of the COVID-19 pandemic on the epidemiological trends of hepatitis A (HA) remains unmeasured in Morocco, in the absence of extended childhood vaccination. This study aims to examine the spatio-temporal epidemiology of HAV in Morocco from 2018 to 2025. We conducted a retrospective, population-based spatio-temporal ecological analysis of 3,051 confirmed HAV cases reported to the national surveillance system of the Moroccan Ministry of Health and Social Protection between January 2018 and December 2025. Phase-specific incidence rate ratios (IRRs) were estimated with negative binomial regression, and changes in level and slope around the pandemic with an interrupted time-series (ITS) model. Trends and breakpoints were described with STL decomposition, the modified Mann-Kendall test and the PELT algorithm. Regional incidence was assessed with standardized incidence ratios (SIRs) and a Bayesian hierarchical BYM2 model, and spatial autocorrelation with global Moran’s I and LISA, across Morocco’s 12 administrative regions. Of the 3,051 reported cases, 969 occurred in 2018–2019, 183 in 2020–2021, 199 in 2022–2023 and 1,700 in 2024–2025. Compared with 2018–2019, incidence was lower in 2020–2021 (IRR = 0.18, 95% CI: 0.12–0.25) and 2022–2023 (IRR = 0.18, 95% CI: 0.14–0.24), and higher in 2024–2025 (IRR = 1.66, 95% CI: 1.39–1.98). In the ITS model, an immediate decrease at the onset of the pandemic (IRR = 0.094, 95% CI: 0.037–0.236) was followed by a significant increase in slope after January 2022 (IRR = 2.91, 95% CI: 1.28–6.61). The long-term trend accounted for 55.5% of the variance and seasonality for 2.2%. Incidence differed markedly between regions, with Fès-Meknès elevated in all phases. No significant global spatial autocorrelation or local clustering was detected. Reported HA incidence in Morocco fell sharply during the COVID-19 period and, in 2024–2025, rose above 2018–2019 levels, with marked and persistent regional differences. These patterns are compatible with an accumulation of susceptible individuals during the pandemic, but changes in healthcare-seeking, testing and reporting may also have contributed, and age-specific, seroprevalence and environmental data are needed to identify the drivers. Such data would inform decisions on extending childhood HA vaccination alongside continued investment in water, sanitation and hygiene (WASH).