Figure 6.15 Influenza waves in an English GP practice. The country practice of a local doctor, Edgar Hope-Simpson, near Cirencester, England. Hope-Simpson made a special study of influenza in the area for some 50 years. (A) Boundaries of the 22 geographical units used by Hope-Simpson for data collection. (B) Location map of Cirencester. (C) Block diagram of cases of clinically-diagnosed influenza A weekly, 1946–74. The earlier appearance of influenza in the pandemic seasons of 1957–58 and 1968–69 is striking, as is the greater number of cases reported.

Source: Data from Cliff et al, Spatial Aspects of Influenza Epidemics, Figures 3.1 and 3.12, p. 48 and 65, Pion, London, UK, Copyright © 1986.