Malaria: can we mention the e-word yet?
Authors: Zoë Mullan
Journal: The Lancet Global Health (2016)

It's World Malaria Day (April 25) and the theme is “End malaria for good”. If I'm not mistaken, that means eradication. In one of the first Comment pieces The Lancet Global Health ever published, Jenny Liu and colleagues asked “Is it possible? Is it worth it? Should we do it?” and the community is still divided. At the annual meeting of the Consortium of Universities for Global Health in San Francisco earlier this month, the director of WHO's Global Malaria Programme, Pedro Alonso, was distinctly circumspect about current prospects. He noted that the first Global Malaria Eradication Programme, launched at the World Health Assembly in 1955, produced quick successes but was ultimately doomed because of a failure to heed history, to do sufficient research, and to listen to technical advice. Eradication had become a “belief system”. He is evidently careful not to let it become one today (note the absence of the e-word in his programme's title). On Liu and colleagues' question of whether eradication was possible, Alonso referred to the three classic indicators of “eradicability”: an effective intervention to interrupt transmission; practical diagnostic tools; and reliance on human beings for the life cycle of the disease agent (ie, there being no other vertebrate reservoir). All is not straightforward for malaria. Although there are effective interventions (particularly insecticide-treated nets [ITNs], indoor residual spraying [IRS], and artemisinin combination therapies), diagnostics are more elusive—the gold-standard microscopy and the more accessible rapid diagnostic tests both have quality and cost issues. Finally, although four of the five Plasmodium species have no other vertebrate hosts, P knowlesi—the dominant species in some parts of southeast Asia—also infects macaques. So there are technical challenges. But, with commitment and consensus, these are not insurmountable in Alonso's cautious opinion. Endorsement at the World Health Assembly last year of the Global Technical Strategy for Malaria was a vital step forward in this regard. The strategy's first “pillar” is to ensure universal access to malaria prevention, diagnosis, and treatment. And with one in four children in sub-Saharan Africa still living in a household with no ITN or IRS, and 60 million infections per year going untreated, there is substantial room for improvement. Keen to demonstrate how much improvement can happen in just 15 years, Alonso pointed to the fact that the number of annual deaths was almost twice as high in 2000 as in 2015, that long-lasting ITNs and IRS did not even exist in 2000, and there was widespread chloroquine resistance and next to no alternatives in the pipeline. As was revealed last week, 2015 was also the first year in which any WHO Region (Europe) had seen zero cases of malaria. With this success in mind, the strategy's second pillar is to accelerate efforts towards malaria-free status within countries (elimination), setting a 2030 target to eliminate the disease in at least 35 new countries, and to prevent its re-establishment. Looking at recent progress again, there were less than five countries with fewer than 10 cases per year in 2000, but more than 20 last year. 25 countries are aiming for elimination by 2020, including Bhutan, whose case study we published in last month's issue. That study showed that malaria burden fell substantially between 2006 and 2014, largely owing to high coverage of long-lasting ITNs. Challenges to the maintenance of malaria-free status will be importation of malaria, especially from India, and the cost of continued ITN and IRS coverage. Cost is indeed an issue. Alonso estimated that financing will need to triple over the next 15 years if the Global Technical Strategy's targets are to be reached. So “Is it worth it?” Another of the key elements of a disease's eradicability is its public health importance, and, for malaria, this is undeniable. There were 214 million new cases of malaria in 2015 and 438 000 deaths, and the disease remains the second greatest cause of death in sub-Saharan Africa (after HIV/AIDS). Finally, should we do it? Or, as others argue, is it better simply to control it to a level at which it is no longer a public health concern? Alonso had a response ready for this very question in San Francisco: “Should we have had that aspiration in the USA?” The concept of Florida and Texas remaining malarious, at some low level, in the 21st century is inconceivable. Why should sub-Saharan Africa be denied the ambition of being malaria-free? Alonso was clear: we're not planning eradication at this stage, but, by 2030, it is something we should be very serious about contemplating once again.