Influenza surveillance 1972–75

Abstract

SUMMARY The surveillance programme described in an earlier report was used to monitor outbreaks of influenza in three successive winters. Influenza virus A was active in all of them, but the only major outbreak of influenza B was in 1973–4. The highest incidence of influenza A was in the 0–4 age group in all three winters, but schoolchildren bore the brunt of infections by influenza virus B.