High prevalence of drug-resistance mutations in Plasmodium falciparum and Plasmodium vivax in southern Ethiopia

Background: In Ethiopia, malaria is caused by both Plasmodium
falciparum and Plasmodium vivax. Drug resistance of P. falciparum
to sulfadoxine-pyrimethamine (SP) and chloroquine (CQ) is frequent
and intense in some areas. Methods: In 100 patients with
uncomplicated malaria from Dilla, southern Ethiopia, P. falciparum
dhfr and dhps mutations as well as P. vivax dhfr polymorphisms
associated with resistance to SP and P. falciparum pfcrt and pfmdr1
mutations conferring CQ resistance were assessed. Results: P.
falciparum and P. vivax were observed in 69% and 31% of the
patients, respectively. Pfdhfr triple mutations and pfdhfr/pfdhps
quintuple mutations occurred in 87% and 86% of P. falciparum
isolates, respectively. Pfcrt T76 was seen in all and pfmdr1 Y86 in
81% of P. falciparum. The P. vivax dhfr core mutations N117 and R58
were present in 94% and 74%, respectively. Conclusion: These data
point to an extraordinarily high frequency of drug-resistance
mutations in both P. falciparum and P. vivax in southern Ethiopia,
and strongly support that both SP and CQ are inadequate drugs for
this region.