Predictors of influenza in the adult population during seasonal and A(H1N1)pdm09 pandemic influenza periods

• Published in: Epidemiology and infection Vol. 142; no. 5; pp. 950 - 954
• Main Authors: GEFENAITE, G., TACKEN, M., KOLTHOF, J., MULDER, B., KOREVAAR, J. C., STIRBU-WAGNER, I., BOS, J., STOLK, R. P., HAK, E.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.05.2014
• Subjects: Adolescent; Adult; Age; Biological and medical sciences; Female; Fundamental and applied biological sciences. Psychology; Humans; Illnesses; Immunization; Influenza; Influenza A Virus, H1N1 Subtype; Influenza, Human - epidemiology; Influenza, Human - virology; Logistic Models; Male; Microbiology; Middle Aged; Miscellaneous; Pandemics; Regression analysis; Retrospective Studies; Seasons; Short Report; Vaccines; Virology; Young Adult; United States > US; Netherlands; descriptive characteristics; seasonal influenza; A(H1N1)pdm09 influenza; Infection; Virus; Influenzavirus A; Influenza A virus; Viral disease; Orthomyxoviridae; Influenza A; Epidemiology
• ISSN: 0950-2688; 1469-4409
• DOI: 10.1017/S0950268813002434

We aimed to assess whether the characteristics of influenza-like illness (ILI) cases in the general population were similar during the seasonal and pandemic A(H1N1)pdm09 influenza periods. We conducted a study using a general population database, which included demographic (sex, age) and clinical (underlying medical conditions, influenza vaccination status) information on more than 80 000 subjects. We assessed the most important predictors of ILI during each season by using multiple logistic regression. We descriptively compared whether they were similar during different seasons. The model, including all demographic and clinical characteristics, showed that age ⩾60 years decreased the odds for ILI by 52% and 81% during the seasonal and A(H1N1)pdm09 pandemic periods, respectively. Being vaccinated decreased the odds of ILI for seasonal influenza by 32%, while suffering from the comorbidities other than lung or cardiovascular diseases doubled the odds of ILI during the A(H1N1)pdm09 pandemic.