Fig. 2

Positive predictive values (PPV) for varying sample sizes of 100 to 500 individuals across the entire community (population size is set at 500). a For high adult burden setting using 0.5 to 5% prevalence threshold values 2 years post-treatment. b For three scenarios using a 1% prevalence threshold value 2 years post-treatment. In a and b the dashed black line is where the PPV is 0.9 and the grey line is where the sample size is 200. The area shaded in red is where PPV < 0.9 and in green is where PPV ≥ 0.9