**7.1 Route 1: southeast Asia to Africa**

One of the most important routes, if not the most important for the spread of CQ-resistant parasite strains is the Southeast Asia to Africa route (**Figure 1a**). The CVIET (mutations in *pfcrt* from codons 72 to 76) lineage are responsible for the spread of CQ-resistance along this route. In the late 1950s, *P. falciparum* resistance to chloroquine was first identified in the Thai-Cambodian border. The spread of CQ-resistant parasites from Southeast Asia to Africa is considered to originate from the Thai-Cambodia border. The CQ-resistant parasites spread to Thailand in 1959 [68], and in Malaysia, Vietnam, and Cambodia in 1962 [68]. By the mid-1970s, CQresistance had been recorded in all Southeast Asia [68]. The SVMNT haplotype, which is mostly confined to the Pacific and South America has been reported in India and Laos [69, 70]. The CVIDT haplotype has also been reported [70, 71]. It remains a mystery whether these minor haplotypes found in Southeast Asia are due to new indigenous mutations or from other areas [68].

The first CQ-resistance was seen in Kenya in 1978 [68]. In the early 1980s, the CQ-resistance parasites spread to Comoro Island [68], Madagascar [68], Uganda [72], Zambia, and Malawi [68]. By the mid-1980s, CQ-resistant parasites had spread to Angola, Namibia [68]; and the western part of Africa, Nigeria, Benin, Togo, Ghana, Senegal, and Gambia [68]. The CVIET haplotype accounts for most of the CQ resistance in Africa [73]. The SVMNT haplotype has also been reported in Tanzania (in 19% of the field isolates) [74], whiles the SVIET haplotype is mostly confined to West Papua has been recorded in the Democratic Republic of Congo [75]. It remains unknown whether these haplotypes migrated from non-African regions or evolved indigenously [76].
