Increased pfmdr1 copy number and sequence polymorphisms in Plasmodium falciparum isolates from Sudanese malaria patients treated with artemether-lumefantrine.

Molecular markers for surveillance of Plasmodium falciparum resistance to current antimalarials are sorely needed. A 28-day efficacy study of artemether-lumefantrine in eastern Sudan identified 5 treatment failures among 100 evaluable patients; 9 further individuals were parasite positive by PCR during follow-up. Polymorphisms in pfatpase6 and pfmdr1 were evaluated by DNA sequencing. One individual carried parasites with a novel pfmdr1 polymorphism (F1044L). pfmdr1 gene amplification in parasites prior to treatment occurred in three individuals who had recurrent infection during follow-up.