Post-COVID-19 Pandemic Rebound of Macrolide-Resistant Infection: A Descriptive Study.

The rebound characteristics of respiratory infections after lifting pandemic control measures were uncertain. From January to November 2023, patients presenting at a teaching hospital were tested for common respiratory viruses and using a combination of antigen, nucleic acid amplification, and targeted next-generation sequencing (tNGS) tests. The number and rate of positive tests per month, clinical and microbiological characteristics were analyzed. A rapid rebound of SARS-CoV-2 was followed by a slower rebound of with an interval of 5 months between their peaks. The hospitalization rate was higher, with infections caused by respiratory viruses compared to . Though the pediatric hospitalization rate of respiratory viruses (66.1%) was higher than that of (34.0%), the 4094 cases of within 6 months posed a huge burden on healthcare services. Multivariate analysis revealed that -infected adults had more fatigue, comorbidities, and higher serum C-reactive protein, whereas children had a higher incidence of other respiratory pathogens detected by tNGS or pathogen-specific PCR, fever, and were more likely to be female. A total of 85% of -positive specimens had mutations detected at the 23rRNA gene, with 99.7% showing A2063G mutation. Days to defervescence were longer in those not treated by effective antibiotics and those requiring a change in antibiotic treatment. A delayed but significant rebound of was observed after the complete relaxation of pandemic control measures. No unusual, unexplained, or unresponsive cases of respiratory infections which warrant further investigation were identified.