{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:56:12Z","timestamp":1785412572473,"version":"3.56.0"},"reference-count":35,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T00:00:00Z","timestamp":1775692800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100021856","name":"Ministero dell\u2019universit\u00e0 e della ricerca","doi-asserted-by":"crossref","award":["2022-NAZ-0524"],"award-info":[{"award-number":["2022-NAZ-0524"]}],"id":[{"id":"10.13039\/501100021856","id-type":"DOI","asserted-by":"crossref"}]},{"award":["2022-NAZ-0524"],"award-info":[{"award-number":["2022-NAZ-0524"]}],"id":[{"id":"https:\/\/ror.org\/0341vw408","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Background: Respiratory syncytial virus (RSV) is a leading cause of hospitalization for acute respiratory tract infection (ARTI) in young children. Respiratory viral coinfections are frequently identified in RSV-related ARTIs, yet their impact on disease severity remains controversial and may vary according to the co-pathogen involved. In the context of evolving RSV prevention strategies, a clearer understanding of RSV coinfection phenotypes is needed. Methods: We conducted a multicenter retrospective cohort study of children aged \u2264 5 years hospitalized for ARTI at two Italian tertiary-care pediatric hospitals between 1 September 2022 and 30 April 2025. Children with laboratory-confirmed RSV infection detected by multiplex polymerase chain reaction were included. Patients were classified as having RSV monoinfection, RSV\u2013rhinovirus coinfection, or RSV\u2013non-rhinovirus coinfection. Severe disease was defined as a composite outcome including intensive care unit (ICU) admission, need for respiratory or hemodynamic support, or death. Association between infection status and severe disease was evaluated using a Poisson regression model with robust variance, adjusted for age, sex, and comorbidities. Results: Among 231 RSV-related hospitalizations, 118 (51.1%) were classified as RSV monoinfection, 65 (28.1%) as RSV\u2013rhinovirus coinfection, and 48 (20.8%) as RSV\u2013non-rhinovirus coinfection. Children with RSV\u2013rhinovirus coinfection were older and had shorter hospital stays. Severe disease occurred in 80.5% of RSV monoinfections, 70.8% of RSV\u2013rhinovirus coinfections, and 75.0% of RSV\u2013non-rhinovirus coinfections. After adjustment, neither RSV\u2013rhinovirus coinfection (adjusted risk ratio [aRR]: 0.93; 95% confidence interval [95% CI]: 0.80\u20131.13) nor RSV\u2013non-rhinovirus coinfection (aRR: 0.99; 95% CI: 0.83\u20131.18) was associated with increased disease severity compared with RSV monoinfection. Conclusions: RSV\u2013rhinovirus and RSV\u2013non-rhinovirus coinfections were not associated with greater disease severity compared with RSV monoinfection in hospitalized children. These findings support pathogen-specific interpretation of multiplex diagnostic results and inform clinical risk stratification in the era of expanding RSV prevention strategies.<\/jats:p>","DOI":"10.3390\/v18040451","type":"journal-article","created":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T07:48:07Z","timestamp":1775720887000},"page":"451","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Disease Severity of Respiratory Syncytial Virus Infection in Hospitalized Children"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3586-0612","authenticated-orcid":false,"given":"Costanza","family":"Di Chiara","sequence":"first","affiliation":[{"name":"Child Health Evaluative Sciences, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-5657-4589","authenticated-orcid":false,"given":"Vera","family":"Rigamonti","sequence":"additional","affiliation":[{"name":"Societ\u00e0 Servizi Telematici\u2014Pedianet, 35138 Padova, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beatrice Rita","family":"Campana","sequence":"additional","affiliation":[{"name":"Pediatric Clinic, Department of Medicine and Surgery, Parma University Hospital, 43126 Parma, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1164-5563","authenticated-orcid":false,"given":"Anna Chiara","family":"Vittucci","sequence":"additional","affiliation":[{"name":"General Pediatric and Infectious Disease Unit, Pediatric Emergency Medicine, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0789-9779","authenticated-orcid":false,"given":"Livia","family":"Antilici","sequence":"additional","affiliation":[{"name":"General Pediatric and Infectious Disease Unit, Pediatric Emergency Medicine, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Flaminia","family":"Ruberti","sequence":"additional","affiliation":[{"name":"Pediatric Clinic, Department of Medicine and Surgery, Parma University Hospital, 43126 Parma, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hajrie","family":"Seferi","sequence":"additional","affiliation":[{"name":"Pediatric Clinic, Department of Medicine and Surgery, Parma University Hospital, 43126 Parma, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-0600-7745","authenticated-orcid":false,"given":"Giulia","family":"Brigadoi","sequence":"additional","affiliation":[{"name":"Department for Women\u2019s and Children\u2019s Health, University of Padova, 35128 Padova, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7105-2105","authenticated-orcid":false,"given":"Daniele","family":"Don\u00e0","sequence":"additional","affiliation":[{"name":"Department for Women\u2019s and Children\u2019s Health, University of Padova, 35128 Padova, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9120-0424","authenticated-orcid":false,"given":"Alberto","family":"Villani","sequence":"additional","affiliation":[{"name":"General Pediatric and Infectious Disease Unit, Pediatric Emergency Medicine, Bambino Ges\u00f9 Children\u2019s Hospital, IRCCS, 00165 Rome, Italy"},{"name":"Systems Medicine Departments, Tor Vergata University of Rome, 00133 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3700-780X","authenticated-orcid":false,"given":"Anna","family":"Cantarutti","sequence":"additional","affiliation":[{"name":"Department of Statistic and Quantitative Methods, Division of Biostatistics, Epidemiology and Public Health, University of Milano-Bicocca, 20126 Milano, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4103-2837","authenticated-orcid":false,"given":"Susanna","family":"Esposito","sequence":"additional","affiliation":[{"name":"Pediatric Clinic, Department of Medicine and Surgery, Parma University Hospital, 43126 Parma, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2047","DOI":"10.1016\/S0140-6736(22)00478-0","article-title":"Global, regional, and national disease burden estimates of acute lower respiratory infections due to respiratory syncytial virus in children younger than 5 years in 2019: A systematic analysis","volume":"399","author":"Li","year":"2022","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1056\/NEJMra1413456","article-title":"Viral bronchiolitis in children","volume":"374","author":"Meissner","year":"2016","journal-title":"N. 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