The efficacy of first-line malaria treatment underpins the success of malaria control programmes. Left untreated, malaria infections will generally recur over many months. These recurrences increase malaria morbidity and enhance transmission. Crucially, suboptimal parasite clearance promotes the emergence of drug resistance. Thus, treatment should aim at total parasite elimination. Defining optimal dose, and monitoring for efficacy, rely on findings from clinical trials done in endemic areas. Patients, although monitored over 4 weeks or longer (depending on the drugs’ pharmacokinetics), are usually discharged within days as symptoms wane and parasites become undetectable microscopically. Drug efficacy, or indeed indication of resistance, are deduced from the occurrence, timing, and frequency of recurrent episodes during follow-up.
For malaria caused by Plasmodium vivax, the species with the broadest global distribution, now and historically, the path to successful treatment has been long. Early last century, Yorke1 showed that whereas recurrences occurred……. see more https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(18)30413-4/fulltext