Mass drug administration should be implemented as a tool to accelerate elimination: against.

In most malaria situations, mass drug administration (MDA) will result in a rapid reduction in the incidence and prevalence of malaria in the target population. However, due to practical reasons MDA hardly ever achieves coverage of the entire population and, therefore, will leave residual malaria infections in the population, from which malaria transmission can be resumed. Depending on the degree of access to prompt diagnosis and treatment and to effective vector control in the area, previous levels of incidence and prevalence will eventually be reached after MDA. It is, therefore, imperative that coverage with these interventions is ensured if MDA is to be implemented. Both effective vector control and access to treatment in combination will also reduce the malaria incidence and prevalence in an area, albeit more slowly than MDA. MDA's role in elimination has to be considered in relation to the following: (1) MDA is logistically difficult, ethically questionable and may evoke parasite resistance to the medicines being used, (2) MDA will only accelerate elimination by reducing the starting number of infections, but that (3) it will be of no benefit to elimination unless both effective vector control and good access to treatment are in place. All malaria elimination efforts have, and will, succeed with good access to treatment, effective vector control, and case surveillance and response systems, and most have not, and will not require MDA. The role of MDA in elimination, if any, will be limited to some very specific situations-small foci of high transmission within a larger area which has made progress towards elimination, to which the former constitutes a continuing source of parasites and, therefore, could jeopardize the elimination effort in the larger area. Elimination of malaria needs not only to be achieved but also be sustained. This is particularly challenging in tropical countries where the risk of re-introduction is high. The haste to eliminate malaria using MDA must be balanced by investment of time and effort to establish effective vector control programmes, and case surveillance and response systems based on diagnosis and treatment services, which are core requisites for achieving elimination, and the latter for sustaining it.

Mass drug administration can be a valuable addition to the malaria elimination toolbox.

The Global Technical Strategy 2016-2030 of the World Health Organization (WHO) has the ambitious goal of malaria being eliminated from at least 35 countries by 2030. However, in areas with once-stable malaria transmission, the reservoir of human infection may be intermittently symptomatic or fully silent yet still lead to transmission, posing a serious challenge to elimination. Mass drug administration (MDA), defined as the provision of a therapeutic dose of an effective anti-malarial drug to the entire target population, irrespective of infection status or symptoms, is one strategy to combat the silent human reservoir of infection. MDA is currently recommended by the WHO as a potential strategy for the elimination of Plasmodium falciparum malaria in areas approaching interruption of transmission, given the prerequisites of good access to case management, effective vector control and surveillance, and limited potential for reintroduction. Recent community randomized controlled trials of MDA with dihydroartemisinin-piperaquine, implemented as part of a comprehensive package of interventions, have shown this strategy to be safe and effective in significantly lowering the malaria burden in pre-elimination settings. Here it is argued that effectively implemented MDA should be kept in the elimination toolbox as a potential strategy for P. falciparum elimination in a variety of settings, including islands, appropriate low transmission settings, and in epidemics and complex emergencies. Effectively implemented MDA using an ACT has been shown to be safe, unrelated to the emergence of drug resistance, and may play an important role in sufficiently lowering the malaria burden to allow malaria transmission foci to be more easily identified, and to allow elimination programmes to more feasibly implement case-based surveillance and follow-up activities. To be most impactful and guard against drug resistance, MDA should use an ACT, achieve high programmatic coverage and adherence, be implemented when transmission is lowest in areas of limited risk of immediate parasite reintroduction, and must always be implemented only once good access to case management, high coverage of effective vector control, and strong surveillance have been achieved. If these considerations are taken into account, MDA should prove to be a valuable tool for the malaria elimination toolbox.