On The Trail Of A Ferocious Killer

The public-health community reversed course on malaria partly because of a reluctance to continue using DDT. But the effort also failed precisely because it came so close to succeeding. Policymakers decided they were finished before they actually were. "They wanted to use their resources on something else that had more cases," says Kimberly Thompson, a risk analyst at Harvard University who has worked on other eradication campaigns. As spraying stopped, malaria staged a comeback. By 1969, Sri Lanka's 18 cases had rocketed back to half a million a year. Disheartened, public-health workers turned away. "One of the selling points had been that this was going to be a relatively time-limited effort," says David Brandling-Bennett, a senior program officer in infectious diseases at the Gates Foundation. "The only thing the effort really succeeded in doing was eradicating malariologists."

As the research community fell into disarray, the malaria parasite gained new ground. A notorious shape-shifter, the parasite is a complex organism with 5,000 genes and a multistage life cycle—perfectly designed to find a human host, infiltrate it and evade any weapons, natural or pharmaceutical, used against it. It enters its victims when mosquitoes bite at night; it slips into the bloodstream and cloaks itself in proteins that the immune system does not recognize. Thus disguised, it makes its way to the liver, where it reproduces rapidly below the radar. By the time the immune system mounts a response, it's often too late.

Drugs may be ineffective because malaria, like many of the world's most dangerous diseases, is highly mutable. Some of its many strains may survive treatment, then spread as hapless doctors watch their drugs become useless in the population at large. That happened in the 1980s, when the malaria parasite developed resistance to chloroquine, the drug most commonly used against it. At the same time, HIV began to ravage Africa, providing newly weakened victims for malaria while drawing away public-health resources. Westerners were largely unaware: by 2000, most thought the disease, which killed 1.1 million people that year—90 percent in Africa—"just wasn't a problem," says Regina Rabinovich, director of infectious diseases at the Gates Foundation.

Change, however, was coming. In 2002, a major new source of financing appeared: the Global Fund to Fight AIDS, Tuberculosis and Malaria, which is now the largest malaria funder in the world. There were technological breakthroughs as well. The most common type of bed net at the time had to be dipped in pesticides every three months to stay effective. In real life, it was largely useless. In the early 2000s, though, scientists developed new nets with long-lasting pesticides woven into the fibers that remain potent up to five years. A new drug also gained prominence in the early 2000s: Coartem, based on a Chinese herb called artemisinin. It was expensive and inconvenient, requiring multiple doses. But unlike chloroquine, it worked. Suddenly, one of the major reasons for inaction was gone: now there were weapons. "In the past, we could say, 'We don't have the nets, we don't have the science, we don't have the technology'," says Prime Minister Brown. "Now, gradually, we were developing the science and the technology, so there was no excuse."

Malaria began to attract high-profile business leaders eager to do good. Raymond Chambers, the reclusive billionaire, had been talking to Sachs. "Jeff showed me photos of little children sleeping in a room, and I commented on how cute they were," says Chambers. "He said, 'You don't understand. They're all in malaria comas. They all subsequently died'." He began to think of malaria as "genocide by apathy" and threw himself into the cause. Meanwhile, Chernin, the COO of News Corp., had become co-chair of Malaria No More, and he leveraged his professional resources: in 2007, he got the producers of a charity "American Idol" episode to feature the disease. Celebrities started visiting Africa on missions. By the 2007 meeting in Seattle, malaria prevention had major momentum. The world's second effort to stamp out the disease was fully underway.

Today, Ethiopia is not the only success story. Many other countries have designed their own plans and used donor money to pay for them. Eritrea, São Tomé and Principe, and Zanzibar have all cut malaria deaths by 50 percent or more since 2000. A tenfold increase in bed nets in Kenya has yielded a 44 percent reduction in child mortality. Even Rwanda, with its grim recent history, says it has reduced deaths from malaria by two thirds. President Paul Kagame says the key has been checking up on local leaders: "The mayors, the counselors, they all have signed performance contracts. They go to homes and follow up to be sure that mosquito nets have actually been used."