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.