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Figure 1 | Malaria Journal

Figure 1

From: Using infective mosquitoes to challenge monkeys with Plasmodium knowlesi in malaria vaccine studies

Figure 1

Survival of heavily and lightly infected mosquitoes. Anopheles dirus mosquitoes were put into several pint containers and allowed to feed on a P. knowlesi infected monkey on consecutive nights, and survival to day 15 was monitored. For each group between 140 and 160 mosquitoes were fed. Figure 1A shows the fraction of mosquitoes surviving from the first night feeds, either on an uninfected monkey or a P. knowlesi-infected monkey (parasitaemia of 0.2%). Figure 1B shows survival of mosquitoes fed on the same two monkeys one day later, when the parasitaemia in the P. knowlesi-infected monkey was 2.6%. Because there was a strong day effect (logrank tests showed significant differences between control groups by day), we used a Cox frailty model using only parasitaemia level of the donor monkey, and with a separate frailty parameter for the four groups. There was a significant difference between the 2.6% group and the combined controls (p = 0.038), but no significant difference between the 2.6% group and the 0.2% group (p = 0.18).

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