{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T15:43:49Z","timestamp":1792597429056,"version":"4.5.0"},"reference-count":38,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T00:00:00Z","timestamp":1776038400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Cell. Infect. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Objectives<\/jats:title>\n                    <jats:p>To characterize the epidemiology, seasonal fluctuations, and co-infection networks of pediatric respiratory pathogens in eastern China following the relaxation of COVID-19 non-pharmaceutical interventions (NPIs).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted a retrospective analysis of 7,473 throat swab samples collected from children (\u226418 years) presenting with acute respiratory tract infections (ARTIs) at a tertiary hospital in Nanjing between January 2024 and May 2025. Samples were tested for 13 common pathogens using a multiplex RT-PCR assay. Pathogen detection rates, temporal trends, and co-infection dynamics were analyzed using Kruskal-Wallis tests, time-series smoothing, and network analysis.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The overall pathogen detection rate was 61.8% (4,618\/7,473), with no significant sex disparity (p = 0.267). Preschoolers (4\u20136 years) experienced the highest burden (68.3%), significantly exceeding other age groups (p &amp;lt; 0.008). Rhinovirus (RV, 16.9%),\n                      <jats:italic>Mycoplasma pneumoniae<\/jats:italic>\n                      (12.4%), and Respiratory Syncytial Virus (RSV, 9.0%) were the most prevalent pathogens. Distinct seasonal signatures were observed: RSV peaked in winter (25.3% in March 2025),\n                      <jats:italic>M. pneumoniae<\/jats:italic>\n                      dominated in mid-summer (22.8% in August 2024), and RV maintained high year-round activity. Co-infections occurred in 17.5% of positive samples, with M. pneumoniae-RV and Adenovirus-RV being the most frequent combinations. Network analysis identified RV and M. pneumoniae as central connectors within the intricate co-infection landscape.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Pediatric respiratory pathogens have returned with strong, age-specific patterns in post-NPI eastern China. The pronounced \u201cimmunity debt\u201d among preschoolers and the high rate of co-infections underscore the urgent need for enhanced multiplex surveillance and the expansion of vaccination programs for RSV and influenza.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fcimb.2026.1795806","type":"journal-article","created":{"date-parts":[[2026,4,13]],"date-time":"2026-04-13T04:44:40Z","timestamp":1776055480000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Epidemiology and co-infection networks of pediatric respiratory pathogens in eastern China after COVID-19 restriction relaxation: a retrospective study"],"prefix":"10.3389","volume":"16","author":[{"given":"Yanqun","family":"Sun","sequence":"first","affiliation":[{"name":"Clinical Medical Research Center, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenshen","family":"Shao","sequence":"additional","affiliation":[{"name":"Department of Cardiothoracic Surgery, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xu","family":"Wang","sequence":"additional","affiliation":[{"name":"Clinical Medical Research Center, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruizhe","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Public Health, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Li","sequence":"additional","affiliation":[{"name":"Clinical Medical Research Center, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Changdi","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ye","family":"Tian","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liming","family":"Cao","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Man","family":"Tian","sequence":"additional","affiliation":[{"name":"Department of Respiratory Medicine, Children\u2019s Hospital of Nanjing Medical University","place":["Nanjing, Jiangsu, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,13]]},"reference":[{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/j.eclinm.2023.102089","article-title":"Why has the epidemiology of RSV changed during the COVID-19 pandemic","volume":"61","author":"Abu-Raya","year":"2023","journal-title":"EClinicalMedicine"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0099392","article-title":"Clinical disease severity of respiratory viral co-infection versus single viral infection: a systematic review and meta-analysis","volume":"9","author":"Asner","year":"2014","journal-title":"PloS One"},{"key":"B4","doi-asserted-by":"publisher","first-page":"30","DOI":"10.1016\/j.mib.2016.11.003","article-title":"Viral-bacterial co-infections in the respiratory tract","volume":"35","author":"Bakaletz","year":"2017","journal-title":"Curr. 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