Evidence map›Paper›PMID 41731510›Full record

ArticleBMC medicine2026

Serological evidence of substantial respiratory syncytial virus infection burden among older adults residing in Swedish long-term care facilities.

Preeti Moar, Christoffer Granvik, Kim Blom, Erick Bermúdez-Méndez, Florian Gegenfurtner, Julia Wigren Byström, Peter Fjällström, Mikael Åberg, Johan Normark, Karin Loré and 2 more

Abstract read
In one paragraph

Article in BMC medicine, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Preeti MoarDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Christoffer GranvikDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Kim BlomDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Erick Bermúdez-MéndezDivision of Immunology and Respiratory Medicine, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Florian GegenfurtnerDivision of Immunology and Respiratory Medicine, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Julia Wigren ByströmDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Peter FjällströmDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Mikael ÅbergDepartment of Medical Sciences, Uppsala University, Uppsala, Sweden.
Johan NormarkDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Karin LoréDivision of Immunology and Respiratory Medicine, Department of Medicine Solna, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden.
Anders F JohanssonDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden.
Mattias N E ForsellDepartment of Clinical Microbiology, Umeå University, 90187, Umeå, Sweden. mattias.forsell@umu.se.

Funding

Region Västerbotten, Sweden RV-993597Science for Life Laboratory Pandemic Laboratory Preparedness program (VC-2022-0028 and VC-2023-0071)Vetenskapsrådet 2020-06235Vetenskapsrådet 2024-03244
6 · The paper itself

Abstract

backgroundOlder adults (> 65 years) residing in long-term care facilities (LTCFs) are at elevated risk of severe outcomes from respiratory infections. Infections often remain undetected or present atypically in this population, leading to underdiagnosis. Our study aimed to estimate the respiratory virus infection burden, independent of symptom presentation, among older adults in Swedish LTCFs in the post-pandemic period (2021-2024).

methodsWe leveraged capillary blood samples and coupled national registry data from 1622 LTCF residents (median age = 87). A multiplex platform was used to quantify antigen-specific IgG and IgM responses to RSV (pre-/post-F, strain A-specific G-protein), influenza-A (H1N1 and H3N2 HA), influenza-B (HA) and SARS-CoV-2 (spike). Linear mixed-effects models were used to demonstrate the dynamics of antibody levels over time, adjusted for age, sex and comorbidities.

resultsRSV-specific antibody responses peaked in spring 2022 (p < 0.001), suggesting an impact of relaxed COVID-19-related restrictions on RSV exposure at LTCFs. RSV-specific antibodies subsequently declined over time until an increase during autumn 2023 (p < 0.001). Geographic variation in pre-F antibody levels suggested localised RSV outbreaks. The total estimated RSV burden at LTCFs was markedly higher than official reports of the Swedish Public Health Agency. Influenza antibody dynamics reflected seasonal trends and were strongly influenced by annual vaccination. A random forest classifier incorporating serological profiles with demographics, location and comorbidities significantly outperformed a model without serological data (AUC-ROC = 0.67 vs. 0.58), although discriminatory performance remained modest. Higher levels of RSV pre-F antibodies in autumn 2021 were associated with increased one-year mortality in logistic regression (OR = 1.43, p = 0.024). Exploratory survival analysis indicated a trend that elevated levels of RSV pre-F antibodies during low population immunity may confer a transiently elevated early hazard of death, although this did not reach statistical significance (HR = 4.50, p = 0.087).

conclusionsWe observed substantial respiratory virus circulation among older adults in Swedish LTCFs and show that RSV burden is under-reported. The results highlight a need for further research into the role of RSV pre-F antibody levels in preventing severe outcomes, potentially via vaccination of LTCF residents. Our scalable serological surveillance system is a valuable approach to detect respiratory infections in LTCFs, independent of symptom presentation or healthcare-seeking behaviour.

Indexed as

Antibodies, ViralLong-Term CareRespiratory Syncytial Virus InfectionsAgedAged, 80 and overFemaleHumansImmunoglobulin GImmunoglobulin MMaleNursing Home ResidentsSwedenAntibodies, ViralImmunoglobulin GImmunoglobulin MImmune monitoringInfluenzaLongitudinal samplingMortalityPopulation immunityRisk factorsRSVSARS-CoV-2VaccinationVulnerable/ high risk population

Identifiers

PMID41731510
PMCPMC12955034

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.