Influenza surveillance in England and Wales: October 1996 to June 1997.

This report summarises information collected for the surveillance of influenza in England and Wales during the winter of 1996/97. Consultations for 'influenza and influenza-like illness' with sentinel general practitioners in England and Wales began to increase towards the end of November and peaked at the start of January. In England, consultations for 'aggregated respiratory disease' (ARD) began to increase a little earlier, perhaps as a result of increased respiratory syncytial virus activity, but also peaked in early January. Influenza A (H3N2) viruses were first detected in early October, but rarely until November, and activity peaked in early January, coinciding with the peak in consultations for flu-like illness. A few influenza B viruses were detected in late November and early December, and substantial activity was recorded in mid-January. Approximately equal numbers of influenza A(H3N2) and B viruses were identified over the winter as a whole, and circulating strains were antigenically similar to those included in the vaccine for 1996/97. Although influenza activity was 'moderate' in terms of consultations and laboratory confirmed infections, a large peak in death registrations occurred at the same time as influenza A(H3N2) virus activity peaked. The number of deaths during the winter was similar to that seen in 1989/90, when the last severe influenza epidemic occurred in England and Wales.