Can improving access to care help to eliminate malaria?
Authors: Azra C Ghani
Journal: The Lancet (2018)

Malaria remains a major cause of morbidity and mortality throughout the world, with 32% of the world's population living in areas of risk.1WHOWorld Malaria Report 2017. World Health Organization, Geneva2017Google Scholar Despite the progress that has been made in reducing the burden of malaria through improved access to preventive interventions,1WHOWorld Malaria Report 2017. World Health Organization, Geneva2017Google Scholar there remain many challenges to the eventual eradication of the parasite. Perhaps one of the greatest challenges is the continual battle with resistance, to both the drugs used to treat the cases and the insecticides used to kill the mosquito hosts.2Ashley EA Dhorda M Fairhurst RM et al.Spread of artemisinin resistance in Plasmodium falciparum malaria.N Engl J Med. 2014; 371: 411-423Crossref PubMed Scopus (1230) Google Scholar, 3Hemingway J Ranson H Magill A et al.Averting a malaria disaster: will insecticide resistance derail malaria control?.Lancet. 2016; 387: 1785-1788Summary Full Text Full Text PDF PubMed Scopus (188) Google Scholar The former problem is particularly acute in the Greater Mekong region in southeast Asia where resistance to the key drug—artemisinin—is now widespread and partner drugs used in combination therapy are also beginning to fail.4Duru V Witkowski B Menard D Plasmodium falciparum resistance to artemisinin derivatives and piperaquine: a major challenge for malaria elimination in Cambodia.Am J Trop Med Hyg. 2016; 95: 1228-1238Crossref PubMed Scopus (41) Google Scholar In response to this, a global concerted effort has been put in place to interrupt malaria transmission in the Greater Mekong region by 2025.5WHOStrategy for malaria elimination in the Greater Mekong subregion (2015–2030). World Health Organization, Geneva2015Google Scholar Although the efficacy of vector control tools in reducing transmission is well established,6Pluess B Tanser FC Lengeler C Sharp BL Indoor residual spraying for preventing malaria.Cochrane Database Syst Rev. 2010; 4 (CD006657.)Crossref Google Scholar, 7Lengeler C Insecticide-treated bed nets and curtains for preventing malaria.Cochrane Database Syst Rev. 2004; 2 (CD000363.)Google Scholar the role of enhanced access to treatment is less well documented. In The Lancet, Jordi Landier and colleagues8Landier J Parker DM Thu AM Lwin KM Delmas G Nosten FH for the Malaria Elimination Task Force GroupEffect of generalised access to early diagnosis and treatment and targeted mass drug administration on Plasmodium falciparum malaria in Eastern Myanmar: an observational study of a regional elimination programme.Lancet. 2018; (published online April 24.)http://dx.doi.org/10.1016/S0140-6736(18)30792-XSummary Full Text Full Text PDF PubMed Scopus (72) Google Scholar report one of the first systematic studies to assess the combined effect of a scaled up programme of increasing early diagnosis and treatment and targeted mass drug administration in four townships of eastern Myanmar on the incidence of Plasmodium falciparum malaria. The programme was provided to all so-called malaria transmission hotspots (villages with >40% malaria of which 20% was P falciparum). Between May 1, 2014, and April 30, 2017, incidence of P falciparum malaria decreased by between 60% and 98% and incidence of Plasmodium vivax malaria decreased by between 52% and 93% across the villages. Before the intervention, hotspot villages had a three-times higher incidence of P falciparum at malaria posts than neighbouring villages (adjusted incidence rate ratio [IRR] 2·7, 95% CI 1·8–4·4). Early diagnosis and treatment was associated with a significant decrease in P falciparum incidence in hotspots (IRR 0·82, 95% CI 0·76–0·88 per quarter) and in other villages (0·75, 0·73–0·78 per quarter). Notably, the length of time that the village malaria post was established were associated with a decrease in malaria incidence, illustrating the importance of improving access to care in reducing local transmission. As would be expected, mass drug administration further reduced P falciparum incidence with an 80% reduction within hotspot villages (IRR 0·19, 95% CI 0·13–0·26). However, by contrast, there was no significant change in the incidence of P vivax malaria. Because of the observational design of the study, there remain several unanswered questions. First, could similar regional reductions be obtained with enhanced early diagnosis and treatment alone? Improving access to prompt diagnosis and treatment is a core aim of the WHO Global Technical Strategy for malaria.9WHOGlobal technical strategy for malaria 2016–2030. World Health Organization, Geneva2015Google Scholar Despite this aim, access remains low in many of the areas with the highest malaria burden.10Bennett A Bisanzio D Yukich JO et al.Population coverage of artemisinin-based combination treatment in children younger than 5 years with fever and Plasmodium falciparum infection in Africa, 2003–2015: a modelling study using data from national surveys.Lancet Glob Health. 2017; 5: e418-e427Summary Full Text Full Text PDF PubMed Scopus (35) Google Scholar Expansion of care through community-based approaches has been gaining traction for many years,11Perry HB Zulliger R Rogers MM Community health workers in low-, middle-, and high-income countries: an overview of their history, recent evolution, and current effectiveness.Annu Rev Public Health. 2014; 35: 399-421Crossref PubMed Scopus (342) Google Scholar with malaria diagnosis and treatment increasingly provided as part of an integrated community case management strategy for malaria, pneumonia, and diarrhoea. Strengthening existing health systems, which should also remain a priority, is likely to require a multifaceted approach to address issues with access, supply chain management, and quality of care across the public, private, and informal health-care sectors.12Rao VB Schellenberg D Ghani AC Overcoming health systems barriers to successful malaria treatment.Trends Parasitol. 2013; 29: 164-180Summary Full Text Full Text PDF PubMed Scopus (46) Google Scholar Second, the definition of a hotspot and its role in sustaining transmission needs to be clarified. Landier and colleagues8Landier J Parker DM Thu AM Lwin KM Delmas G Nosten FH for the Malaria Elimination Task Force GroupEffect of generalised access to early diagnosis and treatment and targeted mass drug administration on Plasmodium falciparum malaria in Eastern Myanmar: an observational study of a regional elimination programme.Lancet. 2018; (published online April 24.)http://dx.doi.org/10.1016/S0140-6736(18)30792-XSummary Full Text Full Text PDF PubMed Scopus (72) Google Scholar defined this on the basis of village prevalence of infection (using ultrasensitive diagnostic tests) compared with others in the same region—ultimately identifying spatial clusters of villages by testing within a 10 km radius of high-prevalence villages. Elsewhere, stratification of malaria interventions is often based on clinic-reported malaria incidence or prevalence of infection from household surveys, or both. However, local hotspots of infection have been shown to be both transient and metric dependent,13Mogeni P Omedo I Nyundo C et al.Effect of transmission intensity on hotspots and micro-epidemiology of malaria in sub-Saharan Africa.BMC Med. 2017; 15: 121Crossref PubMed Scopus (21) Google Scholar and in a randomised controlled trial in the highlands of Kenya, targeting hotspots was not efficacious.14Bousema T Stresman G Baidjoe AY et al.The impact of hotspot-targeted interventions on malaria transmission in Rachuonyo south district in the western Kenyan highlands: a cluster-randomized controlled trial.PLoS Med. 2016; 13: e1001993Crossref PubMed Scopus (64) Google Scholar Further research is therefore required to understand the broader use of this approach and the most appropriate geographical scale for intervention stratification. Finally, the study targeted malaria hotspots using mass drug administration with treatment rounds given once per month for 3 months. Predictably, through clearing the reservoir of asymptomatic infection, this reduced the prevalence of infection, and additionally resulted in a reduction in malaria incidence in the following year. The effect of any transient intervention such as this can be predicted to decline over time;15Brady OJ Slater HC Pemberton-Ross P et al.Role of mass drug administration in elimination of Plasmodium falciparum malaria: a consensus modelling study.Lancet Glob Health. 2017; 5: e680-e687Summary Full Text Full Text PDF PubMed Scopus (52) Google Scholar however, by temporarily reducing malaria incidence, the mass drug administration would have reduced the caseload for staff at the malaria posts, potentially enhancing the effect of early diagnosis and treatment. Undertaking mass drug administration on a large scale can be expensive, and hence its use needs to be compared with not only the health benefits and cost savings that are made through the direct reduction in malaria incidence but also the wider benefits that can be achieved if health-worker capacity is unlocked both in the community and in the broader health-care system. Further research to understanding this balance will help to determine the appropriateness of targeted mass drug administration as a tool to aid malaria elimination. I have received grants from the Bill & Melinda Gates Foundation (includes epidemiological analysis and mathematical modelling of the full range of malaria interventions [existing and novel] including early diagnosis and treatment and mass drug adminstration), Medicines for Malaria Venture (focused on exploring use-case scenarios for different drug profiles, which includes early diagnosis and treatment and mass drug adminstration), Integrated Vector Control Consortium National Institutes for Health, and The Wellcome Trust, and consulting fees from The Global Fund; I am a Trustee for Malaria No More; and I have received non-financial support from WHO and Gavi for attendance at advisory meetings. Effect of generalised access to early diagnosis and treatment and targeted mass drug administration on Plasmodium falciparum malaria in Eastern Myanmar: an observational study of a regional elimination programmeProviding early diagnosis and effective treatment substantially decreased village-level incidence of artemisinin-resistant P falciparum malaria in hard-to-reach, politically sensitive regions of eastern Myanmar. Targeted mass drug administration significantly reduced malaria incidence in hotspots. If these activities could proceed in all contiguous endemic areas in addition to standard control programmes already implemented, there is a possibility of subnational elimination of P falciparum. Full-Text PDF Open Access