Epidemiological profile of respiratory viruses associated with influenza-like illness and severe acute respiratory infection in Guangzhou, China, 2024–2025

Background: The post-pandemic era has brought about marked shifts in the circulation patterns of respiratory pathogens. Nevertheless, comprehensive epidemiological data on acute respiratory infections (ARIs) covering both influenza-like illness (ILI) and severe acute respiratory infection (SARI) remain scarce for southern China. This study aimed to characterize the epidemiological profiles and pathogen spectra of ARIs in Guangzhou, China, from January 2024 to December 2025. Methods: Respiratory specimens were collected from ILI outpatients and SARI inpatients attending two sentinel hospitals in Guangzhou. All specimens were tested for 23 respiratory pathogens using the NxTAG™ Respiratory Pathogen Panel. Statistical analyses were conducted to explore pathogens distribution stratified by patients' demographic characteristics. Results: = 2,223). Influenza virus (IFV, 14.5%) and human rhinovirus (HRV, 10.1%) were predominant. In ILI cases, IFV (19.1%) and HRV (10.9%) were most common; in SARI cases, HRV (8.5%) and respiratory syncytial virus (RSV, 8.2%) prevailed. Marked age-dependent variations were observed: RSV and bocavirus (BOV) primarily infected preschool children, whereas SARS-CoV-2 and IFV were more commonly detected in adults and older individuals. Seasonally, an earlier IFV peak occurring in December and an out-of-season RSV epidemic in 2025 characterized by a summer peak were observed. Co-infections occurred in 9.76% of positive cases, with IFV/HRV most frequent. Positivity rates were higher in ILI (54.1%) than SARI (34.5%). Logistic regression identified advanced age (≥60 years), RSV in children age < 5 years and MP were associated with SARI. Conclusion: These findings reveal that the spectrum of respiratory pathogens in Guangzhou is characterized by dynamic patterns of co-circulation and alternating predominance across different time periods and populations. Highlighting the need for age-specific and seasonally tailored interventions and comprehensive diagnostic tools.