INTRODUCTION The case definition of influenza-like illness (ILI) is a powerful epidemiological tool during influenza epidemics. METHODS A prospective cohort study was conducted to evaluate the impact of two definitions used as epidemiological tools, in adults and children, during the influenza A H1N1 epidemic. Patients were included if they had upper respiratory samples tested for influenza b...

Population-based surveillance of influenza routinely relies on administrative medical encounter databases and ICD-9 codes. However, an assessment of the ICD-9 codes used for the Department of Defense (DoD) influenza-like illness (ILI) case definition has not been conducted since 2007. As coding practices may have changed over time, this analysis was done to determine the sensitivity, specificit...

AIMS To estimate excess morbidity during periods of influenza and respiratory syncytial virus (RSV) activity. METHODS Retrospective analysis of a sentinel practice network database in active and non-active virus periods. MAIN OUTCOME MEASURES clinical diagnoses of new episodes of influenza-like illness (ILI), acute bronchitis, asthma, and otitis media. RESULTS The clinical diagnosis of IL...

We describe and discuss statistical models of Swedish influenza data, with special focus on aspects which are important in on-line monitoring. Earlier suggested statistical models are reviewed and the possibility of using them to describe the variation in influenza-like illness (ILI) and laboratory diagnoses (LDI) is discussed. Exponential functions were found to work better than earlier sugges...

24 Pneumonia and acute exacerbation of chronic illness are leading causes of influenza-related 25 hospitalization. Therefore, influenza and pneumococcal vaccinations are strongly 26 recommended for adults with comorbidities. Using a hospital-based influenza surveillance 27 system, we performed a multicenter, prospective cohort study of patients visiting emergency 28 rooms with influenza-like il...

Infectious disease surveillance systems provide information crucial for protecting populations from influenza epidemics. However, few have reported the nationwide number of patients with influenza-like illness (ILI), detailing virological type. Using data from the infectious disease surveillance system in Japan, we estimated the weekly number of ILI cases by virological type, including pandemic...

BACKGROUND Routine influenza surveillance, based on laboratory confirmation of viral infection, often fails to estimate the true burden of influenza-like illness (ILI) in the community because those with ILI often manage their own symptoms without visiting a health professional. Internet-based surveillance can complement this traditional surveillance by measuring symptoms and health behavior of...

During the 2014-15 influenza season, 13/168 respiratory samples from students with influenza-like illness (ILI) at a college in New York, USA, were positive for human adenovirus (HAdV); 4/13 samples were positive for HAdV-B14p1. During influenza season, HAdV should be included in the differential diagnostic panel used to determine the etiology of ILI.

This is one of the first studies to (1) describe the out-of-hospital burden of influenza-like-illness (ILI) and clinically diagnosed flu, also for patients not seeking professional medical care, (2) assess influential background characteristics, and (3) formally compare the burden of ILI in patients with and without a clinical diagnosis of flu. A general population sample with recent ILI experi...