Plasmodium falciparum and Plasmodium vivax sero-prevalence curves in August and November in the eastern and western region. Sero-prevalence curves for P. falciparum [2A and 2B] and P. vivax [2E and 2F] in the eastern region and in the western region [2C and 2D, 2G and 2H] in August and November 2005. Red triangles represent actual data points, whilst the blue lines represent the maximum likelihood model and 95% confidence intervals. Estimated force of infection (λ) is plotted on the graphs. Two forces infection, along with the age of change, are plotted if deemed necessary by likelihood ratio tests.