新的基因證據(jù)表明,，對(duì)乙胺嘧啶具有高度抗藥性的瘧疾原蟲(chóng)是由東南亞傳入非洲的,。不幸的是，傳入時(shí)間與人們開(kāi)始在非洲用乙胺嘧啶取代另一個(gè)抗瘧藥氯喹同時(shí),，由于抗藥性,，氯喹對(duì)瘧疾原蟲(chóng)已經(jīng)沒(méi)有作用。在此之前,，研究人員曾一直假設(shè),，對(duì)乙胺嘧啶的高度抗藥性是獨(dú)立突變進(jìn)化的結(jié)果。但是,，Cally Roper和同事發(fā)現(xiàn),，有dhfr基因的三個(gè)變異的非洲原蟲(chóng)可以被追溯到東南亞的一個(gè)來(lái)源，這三個(gè)變異結(jié)合起來(lái)產(chǎn)生最強(qiáng)的抗藥性,。強(qiáng)抗藥性進(jìn)入非洲以后,，很快地傳播到整個(gè)大陸。這個(gè)國(guó)際研究小組建議,，對(duì)旅行者篩查和治療也許能幫助遏制抗藥原蟲(chóng)的進(jìn)一步傳播,。作者寫(xiě)到，“重要的是,，這些數(shù)據(jù)顯示對(duì)瘧疾藥物的抗藥性是一個(gè)國(guó)際問(wèn)題,，需要有一個(gè)協(xié)調(diào)的國(guó)際響應(yīng)”。

Intercontinental Spread of Pyrimethamine-Resistant Malaria
Here we present molecular evidence demonstrating that malaria parasites bearing high-level pyrimethamine resistance originally arrived in Africa from southeast Asia. The resistance alleles carried by these migrants are now spreading across Africa at an alarming rate, signaling the end of affordable malaria treatment and presenting sub-Saharan Africa with a public health crisis.