Research Challenges During Low Malaria Incidence in Eswatini: Implication for Achievement of Elimination Targets

In May 2015, governments endorsed the World Health Organisation’s Global Technical Strategy for Malaria 2016 – 2030, a new technical roadmap for countries that are working to reverse and eliminate the spread of malaria. Research is an important component of the Global strategy to evaluate the impact of interventions and monitor progress towards achievement of elimination targets. However, there are critical issues when conducting research in areas with low malaria transmission, particularly identifying and eliminating parasites in asymptomatic infections. Accurate detection of micro-parasitaemic infections and achieving adequate sample sizes to derive statistical power remain a major challenge in the design and conduct of valuable research studies. To monitor progress towards elimination, it is often necessary to quantify Plasmodium infections and artemisinin resistant parasites among the border-crossing populations, including asymptomatic persons. Population movement from high to low transmission areas import infections and facilitate spread of drug resistance. Quantification of the problem of importation of parasites is difficult and complicated by the presence of informal entry points for infections including asymptomatic ones. Surveillance in the context of malaria elimination has to shift from measuring reductions in mortality and morbidity to detecting infections with or without symptoms. The capacity to assess trends and respond without delay has to be developed so that surveillance becomes an additional intervention process. Methods to determine and monitor importation of parasites among people with micro-parasitaemic infections require DNA based techniques such as nested Polymerase Chain Reaction (PCR) and Loop-mediated isothermal amplification (LAMP) which, despite their ability to identify very low parasitaemia, remain expensive for application in field studies. Early warning of the emerging of resistance is needed to identify new foci, predict their spread and inform prompt containment action to counter and slow down the spread of antimalarial and insecticide resistance. It is therefore critical to identify and deploy efficient methods to track signs of reduced efficacy to artemisinin-based combination drugs and insecticides used for indoor residual sprays at the earliest possible time. The efficacy of long lasting insecticide nets (LLINs) in the field is not only determined by direct mortality, but also personal protection and deterrence, for which correlations are much weaker. All these requirements create a challenge in the capacity of the country to conduct comprehensive research to provide information required to maintain a positive drive towards malaria elimination.