FIG. 3.

Age- and exposure-dependent inversion of susceptibility to disease. These graphs illustrate the apparent age-dependent inversion of susceptibility to death caused by P. falciparum with acute (a) versus chronic (b) exposure. Malaria-naive travelers experiencing acute exposure to infection show a sharp increase in the risk of death (odds ratio) with increasing age, whereas the mortality rate for malaria among people living in an area of holoendemic transmission shows the opposite trend. (Reproduced from reference 11 with permission of the Liverpool School of Tropical Medicine.)