Does knowing the influenza epidemic threshold has been reached influence the performance of influenza case definitions?

Background Disease surveillance using adequate case definitions is very important. The objective of the study was to compare the performance of influenza case definitions and influenza symptoms in the first two epidemic weeks with respect to other epidemic weeks. Methods We analysed cases of acute r...

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Detalles Bibliográficos
Autores: Soldevila N., Toledo D., Martínez A., Godoy P., Torner N., Rius C., Jané M., Domínguez A.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Institut d’Investigació Biomèdica Sant Pau (IIB Sant Pau)
Repositorio:r-IIB SANT PAU. Repositorio Institucional de Producción Científica del Instituto de Investigación Biomédica Sant Pau
OAI Identifier:oai:iibsantpau.fundanetsuite.com:p15976
Acceso en línea:https://iibsantpau.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=15976
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133327749&doi=10.1371%2fjournal.pone.0270740&partnerID=40&md5=f314a0004dc55c38d5edb4a595056d0c
Access Level:acceso abierto
Palabra clave:adolescent
adult
aged
Article
Catalonia
child
comparative study
diagnostic procedure
epidemic
fever
flu like syndrome
general practitioner
groups by age
human
influenza
laboratory test
major clinical study
predictive value
respiratory tract infection
retrospective study
season
sentinel surveillance
Child
Epidemics
Fever
Humans
Influenza, Human
Respiratory Tract Infections
Seasons
Sentinel Surveillance
Descripción
Sumario:Background Disease surveillance using adequate case definitions is very important. The objective of the study was to compare the performance of influenza case definitions and influenza symptoms in the first two epidemic weeks with respect to other epidemic weeks. Methods We analysed cases of acute respiratory infection detected by the network of sentinel primary care physicians of Catalonia for 10 seasons. We calculated the diagnostic odds ratio (DOR) and 95% confidence intervals (CI) for the first two epidemic weeks and for other epidemic weeks. Results A total of 4,338 samples were collected in the epidemic weeks, of which 2,446 (56.4%) were positive for influenza. The most predictive case definition for laboratory-confirmed influenza was the WHO case definition for influenza-like illness (ILI) in the first two epidemic weeks (DOR 2.10; 95% CI 1.57-2.81) and in other epidemic weeks (DOR 2.31; 95% CI 1.96- 2.72). The most predictive symptom was fever. After knowing that epidemic threshold had been reached, the DOR of the ILI WHO case definition in children aged <5 years and cough and fever in this group increased (190%, 170% and 213%, respectively). Conclusions During influenza epidemics, differences in the performance of the case definition and the discriminative ability of symptoms were found according to whether it was known that the epidemic threshold had been reached or not. This suggests that sentinel physicians are stricter in selecting samples to send to the laboratory from patients who present symptoms more specific to influenza after rather than before an influenza epidemic has been declared. © 2022 Soldevila et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.