Houston & Houston make a very good case to prevent the introduction of artemisinin- resistant malaria into Africa. But there are good reasons to be somewhat sceptical about the trust the authors put in the robust, affordable technology. The tools used for the diagnosis of malaria were developed for the diagnosis of clinical cases and as we are finding out not for the diagnosis of subclinical carrier states. Using large blood volumes (>1ml) for ultra-sensitive PCR we are now finding an unexpected large submicroscopic parasite reservoir1. Unpublished data suggest that the ratio of infections detected with standard methods to high volume ultra-sensitive PCR are about 1:5. In other words for every infection the authors will detect with their standard methods they will miss about 5 cases which remain undetected. This experimental technology is more complex than standard PCR as the PCR on large blood volumes is not trivial, time consuming and hence expensive1. There remains the problem that even these advanced methods will miss some very low density and sequestered infections.
Based on these facts the proposed screen and treat approach may well be suboptimal for the proposed purpose. The more reliable approach is to treat all peacekeepers from the GMS with a full course of ACTs before setting a foot on African soil. As long as the co-drug is working this combination therapy will still clear even artemisinin tolerant P.falciparum strains. Whether such presumptive treatment is acceptable is another question. If the antimalarial has a long half-life it may well provide prophylaxis against new infections a feature many peacekeepers arriving in a new area may appreciate?

References
1. Imwong M, Hanchana S, Malleret B, Renia L, Day NP, Dondorp A, et al. High-throughput ultrasensitive molecular techniques for quantifying low-density malaria parasitemias. J Clin Microbiol. 2014; 52(9): 3303-9.