Background: Human rhinoviruses (HRVs) exhibit a global circulation characterized by prolonged epidemics and a less concentrated seasonal distribution compared with other respiratory viruses. In this study, we describe the timing, amplitude and duration of HRV epidemics on a global scale, analyzing seasonal patterns in relation to geographic latitude. Methods: HRV surveillance data reported to WHO FluNet from 2016 to 2025 were analyzed. Epidemic peak timing, amplitude and duration were estimated as a function of geographic latitude using harmonic analyses, with a comparison between the pre-pandemic (2016–2019) and post-pandemic (2021–2025) periods. Results: During the study period, 432,399 HRV detections were reported to WHO FluNet across 50 countries. Among these, 24 countries met the predefined criteria for seasonal analysis. Epidemic peak timing showed differences consistent with latitude, with peaks occurring in late autumn and winter in the Northern Hemisphere, during the central months of the year in the Southern Hemisphere, and greater temporal variability in the intertropical belt. Peak amplitude showed marked heterogeneity across countries (median 68.2%, range 28.1–96.7%), while epidemic duration indicated prolonged circulation (median 31 weeks, range 5–48 weeks). A secondary seasonal peak was identifiable in most countries, further supporting the relatively diffuse seasonal profile of HRV circulation. Comparison between the pre- and post-pandemic periods showed largely stable peak timing in most countries, alongside heterogeneous changes in peak amplitude. Conclusions: HRV is characterized by prolonged and weakly concentrated seasonal activity, with epidemic circulation often extending over several months. Despite major epidemiological perturbations during the COVID-19 pandemic, the timing of seasonal peaks remained largely stable across countries, highlighting the epidemiological resilience of HRV and the need for continuous, pathogen-specific surveillance.
Pertussis, caused by Bordetella pertussis, remains a public health concern despite long-standing vaccination programs. After a marked decline during the COVID-19 pandemic, a resurgence was observed in Europe and Italy, with a sharp increase in 2024. This study describes pertussis epidemiological trends in the Tuscany Region (Italy) from 2019 to 2024 to identify high-risk groups and inform prevention strategies. A retrospective population-based analysis was conducted using cases reported to the national surveillance system (PREMAL). Incidence rates were calculated using ISTAT population data, and demographic, temporal, and clinical characteristics were analyzed. Overall, 669 cases were reported (mean annual incidence rate: 3.03/100,000 (IC 95% 2.47–3.59; period incidence rate: 18.2/100,000 (IC 95% 16.81–19.56)), with 89% occurring in 2024 (16.34/100,000 (IC 95% 15.03–17.65)). No sex differences were observed, and most cases were reported in Central Tuscany (64%). Children under 15 years accounted for 87% of cases. The highest incidence was observed among 10–14-year-olds, while infants < 1 year, particularly those under 4 months, showed the highest burden in narrower age strata. Hospitalizations occurred in 12.6% of cases, decreasing substantially in 2024. The 2024 resurgence likely reflects waning immunity, disruptions to routine vaccinations during the pandemic, and reduced pathogen circulation in previous years due to containment and isolation measures related to the pandemic. Strengthening surveillance and improving booster and maternal vaccination coverage are essential to protect vulnerable populations.