Spread of P. falciparum resistance.

Appearance and spread of resistance to former first-line antimalarials chloroquine and pyrimethamine (clear and orange ovals, respectively), showing migration from Southeast Asia to Africa. Emerging resistance to artemisinins is now documented in Southeast Asia, raising concerns about its future migration to Africa. Resistance patterns are overlaid onto a geostatistics map of P. falciparum entomological inoculation rates (EIR; numbers of infectious mosquito bites per individual per year) modeled for 2010 (16).