Figure 3: The annual FOI and transmission efficiency estimated from cross-sectional PR surveys.

The data have been plotted in two ways: (a) the estimated annual FOI and (b) transmission efficiency plotted versus the log of EIR. Each point represents a single study. When several estimates of the EIR or the FOI were reported, a 'spider' was plotted with its centre at the arithmetic mean and legs that connect the center to each one of the estimates. The solid blue line shows a good fit to the data using Equation 1, plotted with b=0.55, α=4.6 and t=43 days. The dashed blue line was drawn with longer times and much higher degrees of heterogeneous biting (that is, with α=10 and t=60 days). Also plotted in red is the heterogeneous biting model fitted to the synthetic cohort study, which serves as an upper bound for this data. The grey line is plotted for reference to show the relationship predicted by the Ross–Macdonald model, assuming b=0.55.