Epidemiological evidence for an association between chloroquine resistance of Plasmodium falciparum and its immunological properties.

The appearance of chloroquine-resistant genotypes o f Plasmodium falciparum has thwarted the goal of global eradication of malaria. Although much effort has been put into understanding the molecular mechanisms of chloroquine resistance, many questions about its distribution remain open: Why, some 30 years after the emergence o f chloroquine resistance, have resistant genotypes not taken over the population? Why have many parasites remained sensitive? Why, after its first appearance in Africa, has chloroquine resistance spread so rapidly through sub-Saharan Africa? In this paper Jacob Koella reviews epidemiological data that suggest that an answer to these questions may involve an association between chloroquine resistance and immunological properties o f malaria parasites.