RSV epidemiology in Primary Care in four Italian regions: A prospective multi-center study in over 60-year-old adults across three winter seasons (2022 - 2023 - 2024)
Keywords:
Respiratory syncytial virus (RSV), Acute respiratory infections (ARI), Primary care, Older adults, surveillanceAbstract
Background: Respiratory syncytial virus (RSV) is an under-recognised cause of acute respiratory infections (ARIs) in older adults, despite a burden comparable to influenza and the recent availability of RSV vaccines. Robust community-based data from Italian primary care are lacking.
Methods: We conducted a prospective, multicentre cohort study in four Italian regions (Liguria, Lombardy, Tuscany, Apulia) over three consecutive winter seasons (2022–2025). Community-dwelling adults ≥60 years presenting to participating general practitioners (GPs) with a WHO-defined ARI were enrolled. Nasopharyngeal swabs were collected and tested using a multiplex RT-PCR respiratory panel. RSV-positive participants were followed by telephone at day 14 (T14) and day 30 (T30). Adjusted prevalence ratios (PRs) for symptoms were estimated with Poisson regression.
Results: Among 664 ARI episodes, 663 had a valid RSV result, and 88 were RSV-positive (13.3%). Positivity rates varied by season (21.7% in 2022–23, 11.9% in 2023–24, and 10.4% in 2024–25) and region (range: 11.2–28.3%), with peaks occurring between ISO weeks 51 and 10. The median age of RSV-positive patients was 75 years (IQR, 68–82); 42% were male. Compared with RSV-negative ARIs, RSV-positive cases had higher adjusted prevalence of cough (PR 1.07, 95% CI 1.02–1.13) and wheezing (PR 1.83, 95% CI 1.14–2.93); other symptoms overlapped substantially. RSV-B predominated (68.2%). Any co-infection occurred in 35.2% of RSV-positive cases, mainly with Haemophilus influenzae and Streptococcus pneumoniae. Median illness duration was 19.5 days (IQR 11.3–30.0). Within 14 days, 65.9% re-contacted their GP and 10.6% sought additional medical care; emergency visits (3.5%) and hospitalisations (2.4%) were uncommon.
Conclusions: Across three winters, RSV accounted for approximately one in eight medically attended ARIs in Italian adults ≥60 years, with prolonged illness also leading to hospitalisations and frequent re-consultations. These findings provide baseline data to support adult RSV vaccination policies and integration of RSV into routine respiratory surveillance in Italy.
References
1. Nguyen-Van-Tam JS, O’Leary M, Martin ET, Heijnen E, Callendret B, Fleischhackl R, et al. Burden of respiratory syncytial virus infection in older and high-risk adults: a systematic review and meta-analysis of the evidence from developed countries. Eur Respir Rev. 2022 Dec 31;31(166):220105.
2. Savic M, Penders Y, Shi T, Branche A, Pirçon JY. Respiratory syncytial virus disease burden in adults aged 60 years and older in high-income countries: A systematic literature review and meta-analysis. Influenza Other Respir Viruses. 2023 Jan;17(1):e13031.
3. Korsten K, Adriaenssens N, Coenen S, Butler C, Ravanfar B, Rutter H, et al. Burden of respiratory syncytial virus infection in community-dwelling older adults in Europe (RESCEU): an international prospective cohort study. Eur Respir J. 2021 Apr;57(4):2002688.
4. Rozenbaum MH, Begier E, Kurosky SK, Whelan J, Bem D, Pouwels KB, et al. Incidence of Respiratory Syncytial Virus Infection in Older Adults: Limitations of Current Data. Infect Dis Ther. 2023 Jun;12(6):1487–504.
5. Wilkinson T, Beaver S, Macartney M, McArthur E, Yadav V, Lied-Lied A. Burden of respiratory syncytial virus in adults in the United Kingdom: A systematic literature review and gap analysis. Influenza Other Respir Viruses. 2023 Sep;17(9):e13188.
6. Domnich A, Calabrò GE. Epidemiology and burden of respiratory syncytial virus in Italian adults: A systematic review and meta-analysis. PLoS One. 2024;19(3):e0297608.
7. Branche AR, Falsey AR. Respiratory syncytial virus infection in older adults: an under-recognized problem. Drugs Aging. 2015 Apr;32(4):261–9.
8. Talbot HK, Falsey AR. The diagnosis of viral respiratory disease in older adults. Clin Infect Dis. 2010 Mar 1;50(5):747–51.
9. Onwuchekwa C, Moreo LM, Menon S, Machado B, Curcio D, Kalina W, et al. Underascertainment of Respiratory Syncytial Virus Infection in Adults Due to Diagnostic Testing Limitations: A Systematic Literature Review and Meta-analysis. J Infect Dis. 2023 Jul 14;228(2):173–84.
10. Ramirez J, Carrico R, Wilde A, Junkins A, Furmanek S, Chandler T, et al. Diagnosis of Respiratory Syncytial Virus in Adults Substantially Increases When Adding Sputum, Saliva, and Serology Testing to Nasopharyngeal Swab RT-PCR. Infect Dis Ther. 2023 Jun;12(6):1593–603.
11. Hurley LP, Allison MA, Kim L, O’Leary ST, Crane LA, Brtnikova M, et al. Primary care physicians’ perspectives on respiratory syncytial virus (RSV) disease in adults and a potential RSV vaccine for adults. Vaccine. 2019 Jan 21;37(4):565–70.
12. Loubet P, Fernandes J, de Pouvourville G, Sosnowiez K, Elong A, Guilmet C, et al. Respiratory syncytial virus-related hospital stays in adults in France from 2012 to 2021: A national hospital database study. J Clin Virol. 2024 Apr;171:105635.
13. Godefroy R, Giraud-Gatineau A, Jimeno MT, Edouard S, Meddeb L, Zandotti C, et al. Respiratory Syncytial Virus Infection: Its Propensity for Bacterial Coinfection and Related Mortality in Elderly Adults. Open Forum Infect Dis. 2020 Dec;7(12):ofaa546.
14. Arexvy | European Medicines Agency (EMA) [Internet]. 2023 [cited 2026 Jan 30]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/arexvy
15. Abrysvo | European Medicines Agency (EMA) [Internet]. 2023 [cited 2026 Jan 30]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/abrysvo
16. mResvia | European Medicines Agency (EMA) [Internet]. 2024 [cited 2026 Jan 30]. Available from: https://www.ema.europa.eu/en/medicines/human/EPAR/mresvia
17. Papi A, Ison MG, Langley JM, Lee DG, Leroux-Roels I, Martinon-Torres F, et al. Respiratory Syncytial Virus Prefusion F Protein Vaccine in Older Adults. N Engl J Med. 2023 Feb 16;388(7):595–608.
18. Ministero della Salute. Misure di prevenzione e immunizzazione contro il virus respiratorio sinciziale (VRS) [Internet]. [cited 2026 Jan 30]. Available from: https://www.seremi.it/sites/default/files/Circolare%20RSV%2027.03.2024_signed.pdf
19. Ministero della Salute - Iniziative volte a promuovere la vaccinazione contro il virus respiratorio sinciziale negli adulti a rischio, nella popolazione anziana e nelle donne in gravidanza per la protezione dei neonati [Internet]. [cited 2026 Jan 30]. Available from: https://www.salute.gov.it/new/it/question-time/iniziative-volte-promuovere-la-vaccinazione-contro-il-virus-respiratorio-sinciziale/
20. Raccomandazioni del Board del Calendario per la Vita sulla vaccinazione contro Virus Respiratorio Sinciziale (VRS o RSV) nella popolazione anziana e negli adulti a rischio [Internet]. [cited 2026 Jan 30]. Available from: https://www.igienistionline.it/docs/2024/01pp.pdf
21. Bracaloni S, Esposito E, Scarpaci M, Cosci T, Casini B, Chiovelli F, et al. RSV Disease Burden in Older Adults: An Italian Multiregion Pilot Study of Acute Respiratory Infections in Primary Care Setting, Winter Season 2022-2023. Influenza Other Respir Viruses. 2024 Dec;18(12):e70049.
22. Scarpaci M, Bracaloni S, Esposito E, De Angelis L, Baglivo F, Casini B, et al. RSV Disease Burden in Primary Care in Italy: A Multi-Region Pediatric Study, Winter Season 2022-2023. Influenza Other Respir Viruses. 2024 Apr;18(4):e13282.
23. Raccomandazioni del Board del Calendario per la Vita sulla vaccinazione contro Virus Respiratorio Sinciziale (VRS o RSV) nella popolazione anziana e negli adulti a rischio [Internet]. [cited 2026 Jan 30]. Available from: https://www.who.int/teams/global-influenza-programme/global-respiratory-syncytial-virus-surveillance/case-definitions
24. Colosia AD, Yang J, Hillson E, Mauskopf J, Copley-Merriman C, Shinde V, et al. The epidemiology of medically attended respiratory syncytial virus in older adults in the United States: A systematic review. PLoS One. 2017;12(8):e0182321.
25. Falsey AR, Hennessey PA, Formica MA, Cox C, Walsh EE. Respiratory syncytial virus infection in elderly and high-risk adults. N Engl J Med. 2005 Apr 28;352(17):1749–59.
26. Broberg EK, Waris M, Johansen K, Snacken R, Penttinen P, European Influenza Surveillance Network. Seasonality and geographical spread of respiratory syncytial virus epidemics in 15 European countries, 2010 to 2016. Euro Surveill. 2018 Feb;23(5):17–00284.
27. CDC. Respiratory Syncytial Virus Infection (RSV). 2025 [cited 2026 Jan 30]. Clinical Overview of RSV. Available from: https://www.cdc.gov/rsv/hcp/clinical-overview/index.html
28. Sundaram ME, Meece JK, Sifakis F, Gasser RA, Belongia EA. Medically attended respiratory syncytial virus infections in adults aged ≥ 50 years: clinical characteristics and outcomes. Clin Infect Dis. 2014 Feb;58(3):342–9.
29. Rezza G, Cereda D, Rizzo C, Cuciniello R, D'Amelio AC, Villani A, Signorelli C. Nirsevimab: a change of paradigm in the prophylaxis of Respiratory Syncytial Virus disease among infants. Ann Ig. 2025 Sep-Oct;37(5):684-688. doi: 10.7416/ai.2025.2712. Epub 2025 Jun 12. PMID: 40503651.
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Copyright (c) 2026 Francesco Baglivo, Federico Tecchio, Maria Sidoti, Matilde Pecchioli, Antonella Lucia D’Atri, Beatrice Casini, Donatella Panatto, Elvira Massaro, Francesca Centrone, Maria Chironna, Elena Pariani, Laura Pellegrinelli, Caterina Rizzo (Author)
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