Post-COVID-19 Dynamics of Pediatric Respiratory Viruses in Wuhan: Epidemiology, Co-Infection Patterns, and Clinical Severity (2023–2024)

Jun’e Ma,1,* Ting Tian,1,* Xuewei Ren,1 Chuanjin Luo,2 Zhengjiang Jin1 1Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 40070, People’s Republic of China; 2State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, People’s Republic of China*These authors contributed equally to this workCorrespondence: Zhengjiang Jin, Email [email protected] Chuanjin Luo, Email [email protected]: This study aimed to investigate the spectrum of respiratory viruses and analyze the clinical characteristics of viral co-infections among children presenting with respiratory symptoms in Wuhan following the COVID-19 pandemic.Methods: A total of 40,846 pharyngeal swabs were collected from children with respiratory tract infections at the Maternal and Child Health Hospital of Hubei Province between January 2023 and August 2024. Nucleic acids of six respiratory viruses were tested, and clinical data from a subset of virus-positive children were retrospectively analyzed.Results: The overall virus positivity rate was 54.55%.Adenovirus (ADV, 18.03%), influenza A (FluA, 12.90%) and respiratory syncytial virus (RSV, 10.63%) were the most prevalent viruses. The positivity rate was slightly higher in male children (55.16%) than in females (53.80%), peaked during winter (70.20%), and was highest among children aged 4– 6 years (58.60%). Among virus-positive cases, 945 (4.24%) had co-infections with two viruses, with the highest co-infection rate observed for RSV and influenza B (FluB,2.03%). Compared to children with RSV single infection, those with RSV co-infection were generally older and presented with a higher incidence and peak of fever, along with elevated white blood cell (WBC), neutrophil (NEU), and monocyte (MONO) counts, higher levels of C-reactive protein (CRP) and interleukin-6 (IL-6), but lower complement 4 (C4) levels. In contrast, RSV single infection was associated with higher rates of oxygen inhalation, severe pneumonia, and elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and creatine kinase (CK).Conclusion: Respiratory viruses remain highly prevalent in symptomatic children in Wuhan, showing distinct patterns. Co-infections can occur among the six viruses studied, with RSV and FluB showing the highest co-infection rate. RSV co-infections are associated with a distinct clinical and inflammatory profile compared to single RSV infections, highlighting the importance of considering co-infection status in clinical management.Keywords: respiratory virus infection, Co-infection, epidemiology, clinical severity, COVID-19