Fig. 3

Short infections are similarly common in all age groups. The distribution of infection durations in Navrongo as estimated by the best-fitting Weibull model is illustrated for all age groups separately. Short infections are similarly common in all age groups, as indicated by the left-skewed PDF. An estimate from non-immune adult malaria therapy patients, where short infections are rare, is shown for comparison [8]. Mean durations are indicated by circles on the abscissa. If infections were cleared shortly after inoculation because of host immunity against particular antigenic variants one would expect an increase in the proportion of short infections with host age, a proxy for cumulative exposure.