Editor—We support Jefferson's recommendation to strengthen surveillance capability for influenza, especially the identification of circulating virus amidst non-specific respiratory illness.1 In north west England the Health Protection Agency has been developing influenza surveillance to increase the coverage of the national consultation system for general practitioners (run by the Royal College of General Practitioners),2 after a successful pilot scheme in 1999 that detected a local epidemic of influenza A in Merseyside.3
This year more than 80 general practices are contributing weekly data on influenza and influenza-like illness to local health protection units. Weekly data are submitted through a web based capture system and viewed over the NHSnet in real time at age specific rates. An electronic weekly bulletin produced by the agency's north west office is disseminated to a wide audience, including primary care trusts and strategic health authorities, and is also available on the website.4
The bulletin includes data on respiratory isolates identified in microbiology laboratories throughout the region. Last winter, good correlation existed between the period of influenza virus isolation and consultations for influenza in primary care (figure), indicating the surveillance system's ability to distinguish increases in influenza from influenza-like illness, despite low levels of circulating influenza compared with respiratory syncytial virus.
Figure 1.
Laboratory isolates of influenza A and respiratory syncytial virus compared with consultation rate for influenza and influenza-like illness in general practice, by week in 2003-4 in north west England
Feedback received indicates that this system is particularly useful to health service staff involved in planning services, by alerting them to local increases and facilitating bed management. In addition, the data are used to determine the appropriate time period for use of antiviral compounds. This system is therefore a good example of surveillance delivering timely intelligence for action.
Competing interests: None declared.
Additional authors are Martyn Regan, consultant regional epidemiologist; Mike Painter, consultant regional epidemiologist; and Keith Paver, clinical virologist—all from the Health Protection Agency North West Laboratory, Manchester.
References
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