FIG. 2.

Onset of age-dependent NAI. The graph illustrates the prevalence of parasitemia (percent) across age groups (years) among malaria-naive newcomers to Indonesian New Guinea. After 8 months of exposure, all ages appear to be equally susceptible to parasitemia detectable by microscopic diagnosis. One year later (20 months), a distinct age-dependent pattern of susceptibility to parasitemia has appeared. These data revealed the onset of NAI to be dependent upon intrinsic age-related factors independent of lifelong, chronic exposure. (Reproduced from reference 11 with permission of the Liverpool School of Tropical Medicine.)