Epidemiological and clinical patterns of viral respiratory infections in two regions of Minas Gerais, Brazil: impact in the post-pandemic period

Background When multiple respiratory viruses co-circulate after the COVID-19 pandemic, interpreting severe acute respiratory infection (SARI) trends requires simultaneous assessment of pathogen prevalence, age distribution and severity markers.Methods In this retrospective cross-sectional study, we evaluated 264 suspected SARI cases (June 2023-September 2024) from two health regions in Minas Gerais, Brazil, tested by RT-qPCR for SARS-CoV-2, influenza A/B (Flu A/B), respiratory syncytial virus (RSV) and human rhinovirus (HRV).Results RSV had the highest detection rate (14.77%), predominated in infants, and yielded the highest hospitalization (69.23%) and ICU admission (55.55%) rates. HRV (11.36%) circulated year-round, whereas SARS-CoV-2 (7.95%) showed irregular activity. Influenza A/B (9.46%) and HRV detections were concentrated among older adults and were also associated with severe presentations. Principal component analysis (PCA) suggested pathogen-specific symptom signatures, and only HRV viral load correlated with hospitalization (p = 0.048). We contextualize these observations with contemporary post-pandemic evidence identified through targeted database searches.Conclusions SARI surveillance should shift toward integrated, year-round monitoring with consistent clinical metadata capture. Prevention strategies, particularly influenza vaccination and RSV immunization, are likely to deliver the most immediate reductions in severe disease burden.