Can syndromic thresholds provide early warning of national influenza outbreaks?
| Autor: | Carol Joseph, Alex J. Elliot, Gillian Smith, Neville Q. Verlander, D. L. Cooper |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Adult
Veterinary medicine medicine.medical_specialty Adolescent Prevalence Common Cold medicine.disease_cause State Medicine Disease Outbreaks Young Adult symbols.namesake Influenza Human Epidemiology Influenza A virus Humans Medicine Poisson Distribution Poisson regression Child Aged Retrospective Studies Wales Influenza A Virus H5N1 Subtype Warning system business.industry Incidence (epidemiology) Public health Infant Newborn Public Health Environmental and Occupational Health Infant Retrospective cohort study Syndrome General Medicine Middle Aged England Child Preschool Population Surveillance Emergency medicine symbols Public Health business Algorithms |
| Zdroj: | Journal of Public Health. 31:17-25 |
| ISSN: | 1741-3850 1741-3842 |
| DOI: | 10.1093/pubmed/fdm068 |
| Popis: | Background Influenza incidence thresholds are used to help predict the likely impact of influenza and inform health professionals and the public of current activity. We evaluate the potential of syndromic data (calls to a UK health helpline NHS Direct) to provide early warning of national influenza outbreaks. Methods Time series of NHS Direct calls concerning ‘cold/flu’ and fever syndromes for England and Wales were compared against influenzalike-illness clinical incidence data and laboratory reports of influenza. Poisson regression models were used to derive NHS Direct thresholds. The early warning potential of thresholds was evaluated retrospectively for 2002‐06 and prospectively for winter 2006‐07. Results NHS Direct ‘cold/flu’ and fever calls generally rose and peaked at the same time as clinical and laboratory influenza data. We derived a national ‘cold/flu’ threshold of 1.2% of total calls and a fever (5‐14 years) threshold of 9%. An initial lower fever threshold of 7.7% was discarded as it produced false alarms. Thresholds provided 2 weeks advanced warning of seasonal influenza activity during three of the four winters studied retrospectively, and 6 days advance warning during prospective evaluation. Conclusion Syndromic thresholds based on NHS Direct data provide advance warning of influenza circulating in the community. We recommend that age-group specific thresholds be developed for other clinical influenza surveillance systems in the UK and elsewhere. |
| Databáze: | OpenAIRE |
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