Spatial distribution of Plasmodium falciparum/Plasmodium vivax network communities overlaid on Plasmodium falciparum/Plasmodium vivax prevalence maps. A) P. falciparum multilevel membership. B) P. vivax multilevel membership. These two maps show only airports that have direct connections from endemic to non-endemic areas, though full origin–destination flow estimates were used in calculations. The inset maps present close-up views of the USA and western Europe. Airports with the same community membership (indicated by the same colour) display stronger links in terms of likely movements of infections between them than to airports in other communities. Note that in the P. vivax map, communities with less than ten airports are not shown.