Fig. 4

(Left) The probability of at least one zygote for the best fitting model parameters (k = 0.6 and blood meal coverage by male gamete of 0.004) is shown in blue–green. Combining the clustering and rapid blood meal search mechanisms creates a close approximation to the Schneider et al. [10] and Da et al. [11] data across all density regimes studied. If the overdispersion parameter k is allowed to vary from 0.5 at low densities, increasing above a gametocyte density of 1/µL at 0.5 per log10 of density, then an even better fit is achieved, as seen in orange for male gamete blood meal coverage of 0.003. (Right) The zygote distributions follow a similar line as the Da et al. [11] data, although the fitting process did not fit to oocyst number. As desired, the mean number of zygotes is almost a full order of magnitude higher than the oocyst counts, with the divergence increasing at higher densities. Note that the varying k plot allows a closer fit to the probability of successful infection while reducing the excessively high zygote counts at the top of the distribution for 100 gc/μl