The results highlight that, when feasible, consideration should be given for trials with a longer follow-up period of 42 days for ACTs with partner drugs that have elimination half-lives comparable to that of lumefantrine, and 63 days for ACTs with slowly-eliminated partner drugs such as piperaquine to capture late treatment failures.
The WHO revised its 2009 guidelines of a recommended 28 days follow-up for ACTs with lumefantrine and 42 days for ACTs with mefloquine that aimed to capture most of the treatment failures without significant logistical difficulties and provide a reasonable approximation on drug efficacy. However, recent studies have reported a substantial proportion of homologous parasitaemia emerging in the peripheral blood after these recommended follow-up periods, suggesting that they warrant scrutiny.
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Read the publication 'Temporal distribution of Plasmodium falciparum recrudescence following artemisinin-based combination therapy: an individual participant data meta-analysis' on the BMC website