{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T16:50:32Z","timestamp":1774543832388,"version":"3.50.1"},"reference-count":53,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T00:00:00Z","timestamp":1774483200000},"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. Microbiol."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Influenza A (H1N1) remains an important seasonal respiratory pathogen, but evidence on its evolutionary dynamics, reported co-detections, and surveillance priorities remains fragmented.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>We conducted an evidence-mapping synthesis (2000\u20132025) integrating bibliometric analysis, expert-guided curation, and sequence\/structure-informed interpretation. A total of 15,028 records were retrieved from PubMed, Web of Science, and Scopus, and 11,848 unique publications were retained after deduplication. GenBank-derived hemagglutinin (HA) sequences and Swiss-Model homology models were used to characterize mutational patterns and structural features. Literature-derived co-detection records were extracted from eligible publications and interpreted using a method-aware framework.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A post-2010 shift in the HA mutational landscape was observed, with recurrent substitutions at sites including S13, S146, S160, and S202. Structure-informed comparison of representative HA models identified a conformationally flexible segment spanning residues aa190\u2013aa226, suggesting potential relevance to the receptor-binding microenvironment. Mapping of literature-derived co-detection records showed that RSV and SARS-CoV-2 were among the most frequently reported co-pathogens; however, these proportions reflected reporting composition across heterogeneous studies rather than population-level co-infection prevalence. In a China-focused module, G219A in Eurasian avian-like (EA) H1N1 strains was prioritized through protocol-constrained expert annotation requiring isolate-level evidence and was interpreted as a hypothesis-generating site of interest within the receptor-binding region rather than an algorithm-derived global bibliometric signal.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Discussion<\/jats:title>\n                    <jats:p>This study provides an integrated overview of H1N1 research evolution, HA mutational change, and reported co-detection patterns over the past 25 years. The findings support a tiered, method-aware multi-pathogen surveillance framework for preparedness, while underscoring that heterogeneous literature-derived co-detection data require standardized definitions, assay-aware interpretation, and local calibration before translation into clinical or public health decision-making.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fmicb.2026.1793244","type":"journal-article","created":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T15:55:03Z","timestamp":1774540503000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Evolutionary trajectory and co-infection dynamics of human influenza A(H1N1) virus (2000\u20132025): an integrated framework informed by expert-informed bibliometrics"],"prefix":"10.3389","volume":"17","author":[{"given":"Xinrui","family":"Cao","sequence":"first","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiahui","family":"Tang","sequence":"additional","affiliation":[{"name":"The First Clinical Medical College, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yang","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoyu","family":"Wang","sequence":"additional","affiliation":[{"name":"The First Clinical Medical College, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qi","family":"Li","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yingxue","family":"Xu","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xinran","family":"Li","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Feipeng","family":"Zhao","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Mudanjiang Medical University","place":["Mudanjiang, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,3,26]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"3035","DOI":"10.1007\/s00705-018-3962-z","article-title":"Evolution and dynamics of the pandemic H1N1 influenza hemagglutinin protein from 2009 to 2017","volume":"163","author":"Al Khatib","year":"2018","journal-title":"Arch. 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