Annual Incidence

The accompanying graph (1) shows the annual incidence over three and a half years among all troops in the Middle East, and it will be seen that the epidemics recurred each year at the same time but with less intensity, and were associated with, but later than, the fly maximum. Graph 2 shows 2 NZEF incidence from 1942 to 1944. Among New Zealand troops there is not the same falling-off in incidence, due no doubt to such factors as large numbers of reinforcements.

The Middle East is considered an endemic area where jaundice is a common complaint of children but rare in adults, whereas adults coming into the area are readily infected.