Fig. 1.

The force of infection (FOI) comparison between Fine and Carneiro (1999) and Vallejo et al. (2017). The forces of infection for the study populations in Fine and Carneiro (1999) were derived using the formula given in Dietz (1974). We note that the formula utilizes the life expectancy of the study population. For this we used Nations (2004), which is the 2002 revision. The results in Fine and Carneiro (1999) were constructed using the 1994 revision. Therefore, there may be slight differences in the force of infection depending on the revision used. The forces of infection in Vallejo et al. (2017) were derived using the inverse of the average age at first infection at equilibrium.