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Is setting a deadline for eradicating malaria a good idea? Scientists are divided

A woman watches over a child with malaria in a hospital in Jacqueville, Ivory Coast, in April.

SIA KAMBOU/AFP/Getty Images

By Martin Enserink

In 2007, philanthropists Bill and Melinda Gates stunned many scientists when, at a meeting in Seattle, Washington, they called for the worldwide eradication of malaria. Many felt malaria was so
entrenched—there were almost 250 million cases annually—and so difficult to fight that any talk of eradication was premature. But it’s hard to ignore two of the world’s most generous funders, and both the World Health Organization (WHO) and researchers embraced the idea. Soon, a flurry of working groups, scientific papers, and public health strategies were laying the groundwork.

But the consensus is dissolving. Last week, WHO dropped a minor bombshell of its own when it released the summary of a report that says malaria eradication isn’t feasible in the foreseeable future. And it argues that setting any deadline will undermine disease control efforts, as it did when WHO set a similar goal 64 years ago. “We must not set the world up for another failed malaria eradication effort that could derail attempts to achieve our vision for decades,” says the report from WHO’s Strategic Advisory Group on Malaria Eradication (SAGme).

“It’s a watershed moment,” says Willem Takken, a retired medical entomologist from Wageningen University & Research in the Netherlands. “Basically WHO now admits we won’t get rid of malaria anytime soon.”

A second high-caliber group, however, disagrees. On 9 September, the Lancet Commission on Malaria Eradication, a group of 26 academics from around the globe, will publish a study recommending that the world set a 2050 target for eradication, sources tell Science. The commission will also offer a timeline and concrete steps for reaching the goal. A deadline will help raise money and keep the field energized, says Arjen Dondorp, head of the Mahidol Oxford Tropical Medicine Research Unit in Bangkok and a member of the Lancet group: “It’s mainly about keeping up the spirit.”

The Lancet commission plans a high-profile announcement at WHO headquarters in Geneva, Switzerland, followed by events in London and Washington, D.C. That prompted a preemptive strike by SAGme. It published its summary and held a press conference last Thursday, even though its full report is months away, “partly because of the noise that may be generated around” the Lancet report, says Pedro Alonso, director of WHO’s Global Malaria Programme. “It is making sure that the community doesn’t go down a single line of thinking.”

The debate is about more than just the usefulness of bold goals in global health. The focus on eradication has skewed scientists’ and funders’ priorities, says Brian
Greenwood, a malariologist at the London School of Hygiene & Tropical Medicine. For instance, much energy has been spent in countries on the fringes of the malaria map—such as Sri Lanka, Bhutan, and El Salvador—where eliminating the parasite was relatively easy. Such “early wins” boosted morale but diverted attention from African countries where thousands of children were dying of malaria, Greenwood says. He recalls seeing 16 children with cerebral malaria in a hospital in Sierra Leone and thinking that talk of eradication was premature.

What you end up with is donor fatigue, public fatigue, and loss of political will and commitment.

William Moss, Johns Hopkins Bloomberg School of Public Health

WHO first adopted the goal of malaria eradication in 1955, after the insecticide DDT made killing mosquitoes easy and cheap. The effort saw major successes until insecticide resistance emerged. The campaign made little headway in Africa, however, and in 1969 the World Health Assembly moved to effectively end it by shifting responsibility for malaria control to national governments, while still retaining eradication as a long-term goal. That caused interest in the disease to plummet and the parasite to resurge.

When the Bill & Melinda Gates Foundation revived the E word in 2007, it didn’t mention a deadline. Bill Gates later said it would take “multiple decades” and acknowledged it was “dangerous” to set unattainable goals. Still, Margaret Chan, then WHO’s director, pledged the agency’s support, and the eradication goal began to shape policy and research.

Alsonso and Marcel Tanner, a former director of the Swiss Tropical and Public Health Institute in Basel, headed a group that published a series of papers called the Malaria Eradication Research Agenda in 2011, for instance, and the Barcelona Institute for Global Health in Spain, which Alonso headed until he joined WHO in 2014, became host to the Malaria Eradication Scientific Alliance, which sought to support the eradication plan with evidence.

But Alonso thought the feasibility of eradication needed a closer look, and in 2016 he convened SAGme and asked Tanner to lead the panel. Its report, which partly relied on modeling by a team at the University of Oxford in the United Kingdom, says eradication is still a long-term goal worth pursuing, and that time is on humanity’s side: Megatrends such as socio-economic development, urbanization, and climate change—which can influence transmission by changing temperature, humidity, and rainfall—will all help drive down malaria incidence. But it concludes that even in the rosiest of scenarios, there will still be 11 million cases in 2050.

The Lancet panel used models from the same Oxford group and will concur with many of SAGme’s findings, Dondorp says. But he and others argue that the Gates Foundation’s embrace of eradication reinvigorated malaria research, attracted money, and boosted control efforts. That helped trigger a decadelong decline in cases, from an estimated 247 million in 2006 to 214 million in 2015. (The decline has flattened since then, however, and a WHO plan to reduce incidence by 40% between 2015 and 2020 is badly off track.)

Whether the Lancet commission’s 2050 target could deliver a similar boost is unclear; 2050 is so distant that “it’s not really a target at all,” says William Moss, a malaria researcher at the Johns Hopkins Bloomberg School of Public Health in Baltimore, Maryland. He notes that other Gates-backed eradication campaigns, such as those for polio and Guinea worm, have repeatedly missed deadlines. “What you end up with,” he says, “is donor fatigue, public fatigue, and loss of political will and commitment.”

How Bill and Melinda Gates feel about the rift is unclear. Philip Welkhoff, director for malaria at the Gates Foundation in Seattle, says he can’t speak for the couple, but he is a member of SAGme and supports its conclusions. “My personal take is that the most effective goals are the ones that are in a 10- to 12-year time frame,” he says. “That’s where the energy should go.” At the same time, he says, “Our leadership and myself are completely committed to carrying through all the way to eradication. We are in it for the long haul.”


Source: Science Mag