Incidence of Respiratory Syncytial Virus-Associated Hospitalization Among Adults in Ontario, Canada, 2017-2019

Sarah A Buchan^{1

2

3

4

5}, Jenna Alessandrini¹, Samantha S M Drover⁴, Melissa K Andrew^{6

7}, Susan E Bronskill^{3

4

5

8}, Kevin A Brown^{1

3}, Nick Daneman^{1

4

5

9}, Shelley L Deeks¹⁰, Jonathan B Gubbay^{11

12

13}, Jennie Johnstone^{14

15}, Timothy M Karnauchow^{16

17}, Samantha Lee⁴, Allison J McGeer^{3

18

19}, J Dayre McNally²⁰, Shelly A McNeil⁷, Samira Mubareka^{19

21

22}, Michelle Murti³, Marek Smieja²³, Sarah E Wilson^{1

2

3

4}, Jeffrey C Kwong^{1

2

3

4

24

25}

Affiliations

¹ Communicable Disease Control, Public Health Ontario, Toronto, Ontario, Canada.
² Centre for Vaccine Preventable Diseases, University of Toronto, Toronto, Ontario, Canada.
³ Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
⁴ Research and Analytics, ICES, Toronto, Ontario, Canada.
⁵ Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario, Canada.
⁶ Department of Medicine (Geriatrics), Dalhousie University, Halifax, Nova Scotia, Canada.
⁷ Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, Canada.
⁸ Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
⁹ Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
¹⁰ Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada.
¹¹ Department of Pathology and Laboratory Medicine, British Columbia Children's and Women's Hospitals, Vancouver, British Columbia, Canada.
¹² Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
¹³ British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
¹⁴ Division of Infectious Diseases, Sinai Health, Toronto, Ontario, Canada.
¹⁵ Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
¹⁶ Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
¹⁷ Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada.
¹⁸ Department of Microbiology, Sinai Health, Toronto, Ontario, Canada.
¹⁹ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
²⁰ Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
²¹ Department of Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
²² Shared Hospital Laboratory, Toronto, Ontario, Canada.
²³ Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
²⁴ Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada.
²⁵ Toronto Western Family Health Team, University Health Network, Toronto, Ontario, Canada.

PMID: 40736447
PMCID: PMC12614998
DOI: 10.1093/infdis/jiaf343

Incidence of Respiratory Syncytial Virus-Associated Hospitalization Among Adults in Ontario, Canada, 2017-2019

Sarah A Buchan et al. J Infect Dis. 2025.

. 2025 Nov 14;232(5):e799-e810.

doi: 10.1093/infdis/jiaf343.

Authors

Affiliations

¹ Communicable Disease Control, Public Health Ontario, Toronto, Ontario, Canada.
² Centre for Vaccine Preventable Diseases, University of Toronto, Toronto, Ontario, Canada.
³ Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
⁴ Research and Analytics, ICES, Toronto, Ontario, Canada.
⁵ Institute of Health Policy, Management, and Evaluation, University of Toronto, Toronto, Ontario, Canada.
⁶ Department of Medicine (Geriatrics), Dalhousie University, Halifax, Nova Scotia, Canada.
⁷ Canadian Center for Vaccinology, Dalhousie University, Halifax, Nova Scotia, Canada.
⁸ Sunnybrook Research Institute, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
⁹ Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
¹⁰ Community Health and Epidemiology, Dalhousie University, Halifax, Nova Scotia, Canada.
¹¹ Department of Pathology and Laboratory Medicine, British Columbia Children's and Women's Hospitals, Vancouver, British Columbia, Canada.
¹² Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
¹³ British Columbia Children's Hospital Research Institute, University of British Columbia, Vancouver, British Columbia, Canada.
¹⁴ Division of Infectious Diseases, Sinai Health, Toronto, Ontario, Canada.
¹⁵ Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
¹⁶ Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
¹⁷ Department of Pathology and Laboratory Medicine, University of Ottawa, Ottawa, Ontario, Canada.
¹⁸ Department of Microbiology, Sinai Health, Toronto, Ontario, Canada.
¹⁹ Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
²⁰ Research Institute, Children's Hospital of Eastern Ontario, Ottawa, Ontario, Canada.
²¹ Department of Laboratory Medicine and Molecular Diagnostics, Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
²² Shared Hospital Laboratory, Toronto, Ontario, Canada.
²³ Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, Canada.
²⁴ Department of Family and Community Medicine, University of Toronto, Toronto, Ontario, Canada.
²⁵ Toronto Western Family Health Team, University Health Network, Toronto, Ontario, Canada.

PMID: 40736447
PMCID: PMC12614998
DOI: 10.1093/infdis/jiaf343

Abstract

Background: Respiratory syncytial virus (RSV) causes substantial morbidity and mortality among adults. Given recent RSV vaccine authorizations, data on groups at highest risk are needed to support vaccine program decision making.

Methods: We identified adults aged ≥ 18 years hospitalized with laboratory-confirmed RSV and hospitalizations with RSV-related diagnostic codes in Ontario, Canada (2017-2019). We calculated incidence of hospitalization with 95% confidence intervals (CIs) using Poisson regression stratified by demographic and clinical risk factors, and substratified by age. We reported secondary outcomes including the proportion of individuals with fatal outcomes.

Results: Over 2 respiratory virus seasons, we identified 3928 RSV-associated hospitalizations. Incidence increased steadily with age from 2.0 (95% CI, 1.8-2.3) per 100 000 for those aged 18-49 years to 43.7 (95% CI, 41.0-46.6) per 100 000 for those aged 70-79 years, with a sharp increase to 134.7 (95% CI, 128.6-141.1) per 100 000 for those aged ≥ 80 years. Incidence was higher for those with comorbidities, including chronic kidney disease (receiving dialysis) (494.7; 95% CI, 410.7-595.8) and transplant recipients (370.9; 95% CI, 318.0-432.6), as well as for those living in lower (22.4; 95% CI, 21.1-23.7) versus higher-income neighborhoods (11.8; 95% CI, 10.8-12.8). Among those hospitalized, 10.3% (n = 403) died within 30 days of admission, and 93.1% of deaths occurred in those aged ≥ 60 years. Of survivors, 44.6% of community-dwelling adults aged ≥ 60 years had functional decline requiring formal supports at discharge.

Discussion: We found a substantial burden of RSV among older adults, particularly among those with preexisting medical conditions and those of lower socioeconomic status. These results will inform equitable vaccine recommendations for adults.

Keywords: RSV; administrative data; adult; hospitalization; risk factors.

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Conflict of interest statement

Potential conflicts of interest. A .J. M. reports research grants to her institution from Pfizer and Sanofi; and receipt of personal fees for advisory boards, presentation of webinars, and/or data safety monitoring board participation from Astra-Zeneca, GSK, Merck, Moderna, Pfizer, Roche, Sanofi, and Seqirus. S. S. M. D. works as a part-time independent consultant for CERobs Consulting, LLC (cerobs.com), which involves preparing psychometric property reports, validation analysis plans, and other similar reports for clinical outcome assessments and patient-reported outcomes. J. B. G. is a paid consultant scientific editor for GIDEON Informatics, Inc (https://www.gideononline.com/), which is unrelated to the current work. S. A. M. reports research funding to her institution from Merck, Pfizer, Regeneron, and GlaxoSmithKline; and has received personal fees for consulting, data safety monitoring boards, and advisory boards from GlaxoSmithKline, Merck, Moderna, Sanofi, and Pfizer. All other authors report no potential conflicts.

Figures

**Figure 1.**
Mean annual incidence of RSV-associated hospitalization per 100 000 adults in Ontario by number of identified comorbidities, stratified by age. Error bars represent 95% confidence intervals. Abbreviation: RSV, respiratory syncytial virus.

**Figure 2.**
Mean annual incidence of RSV-associated hospitalization per 100 000 adults in Ontario by comorbidity status, stratified by age. Incidence estimates based on numerator cell counts < 6 are not displayed following ICES privacy guidelines. Error bars represent 95% confidence intervals. Error bars for CKD (receiving dialysis) extend beyond graph limits as indicated by arrows. Abbreviations: CKD, chronic kidney disease; COPD, chronic obstructive pulmonary disease; RSV, respiratory syncytial virus.

**Figure 3.**
Mean annual incidence of RSV-associated hospitalization per 100 000 adults in Ontario by degree of frailty and prior dwelling type/care requirements, stratified by age. Incidence estimates based on numerator cell counts < 6 are not displayed following ICES privacy guidelines. Error bars represent 95% confidence intervals. Abbreviation: RSV, respiratory syncytial virus.

See this image and copyright information in PMC

References

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1. Prasad N, Newbern EC, Trenholme AA, et al. The health and economic burden of respiratory syncytial virus associated hospitalizations in adults. PLoS One 2020; 15:e0234235. - PMC - PubMed

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Incidence of Respiratory Syncytial Virus-Associated Hospitalization Among Adults in Ontario, Canada, 2017-2019

Affiliations

Incidence of Respiratory Syncytial Virus-Associated Hospitalization Among Adults in Ontario, Canada, 2017-2019

Authors

Affiliations

Abstract

Conflict of interest statement

Figures

References

MeSH terms

Grants and funding

LinkOut - more resources

Full Text Sources

Medical