Fig. 6. Example of mutation flow during years 16 to 20 of a 5-year cycling strategy, where DHA-PPQ is used first, ASAQ second, and AL last.
PfPR2-10 is 5% and treatment coverage is 40%. The diagram shows mutation flow during the second period of DHA-PPQ usage for a ‘median’ simulation. The median simulation was chosen by minimizing the absolute distance (among 100 runs) to the five median frequency lines shown in Fig. 2. Drug-sensitive genotypes are shown in green, single-resistant genotypes in blue, and the double-resistant to DHA-PPQ is shown in crimson (“2” connotes PPQ-resistance). Mutation occurs from left to right, and the width of the flow is proportional to the absolute number of mutations during the five-year period. A total of 372 mutations to the maximally-resistant triple-resistant (TYY--Y2) occur in years 16–20 of a 5-year cycling policy while the corresponding number of mutations for an MFT policy is 318. The total number of mutations to DHA-PPQ-AQ triple-resistant over 20 years is 581 for 5-year cycling (this figure) and 498 for MFT. Mutations shown are mutations that emerge and fix within host. Recombination occurs in the model but recombination events are not shown in the diagram.