Table 1

Part A: summary of parameter values describing gametocytaemia in untreated infections, as fitted to 76 malaria therapy patients. Best-fit values were obtained for each patient, as described in the Methods section. The distributions stated here describe the large variation observed within the group of patients studied. In each case, four distributions were assessed for goodness of fit (normal, log-normal, gamma and Weibull distributions). We sample from these distributions to generate dynamics in our within-host model. The median value of α is 0.011, while the mean gametocyte maturation time is 7.6 days. Part B: best-fit parameters and units for the PD model, describing the rate at which AL kills gametocytes, as defined in Eq. (1). Parameter Embedded Image is the maximum (max.) killing rate for drug j against gametocyte stage Embedded Image . Eq. (1) shows how killing rates depend on drug concentration, with killing rates halved at the Embedded Image concentration of each drug. For both drugs we retain the Embedded Image concentrations fitted in a previous publication.14

A. Parameters governing the gametocyte dynamics
ParameterDistributionDescription
α Log-normal distribution Embedded Image , Embedded Image . Distribution truncated at 0.3Commitment rate of asexual parasites
Embedded Image Normal distribution, Embedded Image , Embedded Image . Distribution truncated at (1, 3)Mean time spent in each immature gametocyte stage (in days)
Embedded Image Normal distribution, Embedded Image , Embedded Image . Distribution truncated at (1.4,16)Mean circulation time of mature gametocytes (in days)
B. Pharmacodynamic parameters for AL against gametocytes
Value for AM (95% credible intervals in brackets)Value for LMFFixed or Fitted
Embedded Image 0.180.13FixedMax. killing rate of stage 1 and 2 gametocytes (1/hour)
Embedded Image 0.11 (0.09–0.12)0.04Fitted for AM, fixed for LMFMax. killing rate of stage 3 and 4 gametocytes (1/hour)
Embedded Image 0.08 (0.07–0.10)0Fitted for AM, fixed for LMFMax. killing rate of stage 5 (mature) gametocytes (1/hour)
Embedded Image 3.3125Fitted previously for asexual parasites14 Drug concentration (ng/ml) at which killing rate is half of its maximum
  • AL, artemether-lumefantrine; AM, artemether; LMF, lumefantrine.