Measles Surveillance in Tuscany (Italy), 2019–2024: A Six-Year Epidemiological Analysis

Background: Despite sustained public-health efforts, measles continues to re-emerge in Europe. According to the ECDC, 1045 measles cases were reported in Italy in 2024. We describe epidemiological trends and characteristics of measles cases in the Tuscany Region from 2019 to 2024. Methods: We conducted a population-based retrospective study using cases reported through the national surveillance system (PREMAL). Incidence rates were calculated using demographic data from the Italian National Institute of Statistics (ISTAT). Cases were stratified by year, sex, age group, vaccination status (2024), and hospital admission; temporal, demographic, and clinical trends were analysed. Results: From 2019 to 2024, 204 cases were reported, corresponding to a mean annual incidence of 0.93 per 100,000 population (95% CI: 0.80–1.07) and a cumulative incidence of 5.58 per 100,000 (95% CI: 4.78–6.31). Females accounted for 63.2% of cases (n = 129). After a peak in 2019 (n = 116), with an incidence of 3.13 per 100,000 (95% CI: 2.56–3.71), cases sharply declined during 2020–2023, followed by a resurgence in 2024 (n = 75), with an incidence of 2.05 per 100,000 (95% CI: 1.59–2.51). Children aged 0–4 years represented 7.4% of cases but had the highest age-specific incidence (12.19 per 100,000). Adults aged 25–64 years accounted for 70.1% of all cases, indicating the greatest absolute burden. Incidence was higher among individuals aged 25–44 years (11.56 per 100,000) than among those aged 45–64 years (4.30 per 100,000). Overall, 41.7% of cases required hospitalization. In 2024, most cases occurred in unvaccinated individuals (n = 56), while vaccination status was unknown for five cases. Conclusions: The 2024 measles resurgence in Tuscany mainly affected unvaccinated adults. These findings highlight persistent immunity gaps among adults, suggesting that protection and prevention measures are also needed in the population (0–4 y).