Malaria Prevention: A Train Wreck?
Malaria, that ancient scourge, survives. Over the past century, as sanitation and medical advances have conquered or controlled other diseases, malaria has resisted eradication. In 2010, the disease infected about 219,000,000 people and killed 660,000, almost all in developing countries.
When it comes to malaria intervention, sometimes I feel like I’m watching a train heading over a cliff in slow motion. Not only that, it’s happened before, along the same stretch of track, during the failed global eradication effort of the 1950s and 60s. My colleagues in malaria intervention agree that it’s failing, but there’s not much work underway to avert failure.
If you get your malaria news from the media, this might surprise you. News reports make things seem rather promising. True, malaria-related deaths in African children have declined, and the latest vaccine candidate is an improvement over the last one. People still talk as if eradication is a real possibility.
Yet away from the PR, on the front lines, battles are being lost. In Ethiopia, insecticide resistance now allows 99.5 percent of tested mosquitoes to survive DDT exposures that used to kill every one of them. Our best drugs are beginning to fail, too. Up to 20 percent of the malaria cases occurring along the Thai-Cambodia border no longer respond promptly to treatment. Of course, any intervention based on biocides is doomed to be temporary. Nature and evolution ensure that.
One of the simplest prevention methods — fine-mesh bed nets that prevent mosquitoes from infecting humans — is losing ground. Despite enormously successful distribution campaigns, usage declines as nets are diverted to other uses: storing grain, tethering oxen or catching fish. And the nets don’t last nearly as long as they should: within months, the flimsier meshes become riddled with holes that allow free entry to mosquitoes. Thus, it’s not surprising that in some places, the clinical impact of net ownership is negligible. Kids in Zambia who use bed nets are no less anemic than those who don’t.
So what’s to be done?
Most eyes seem fixed on the long-term goal — eradication. While we continue to push bed nets as the proximal solution, not much work is getting done on replacing, improving or complementing them. Part of the problem is an imbalance between basic and applied research. Less than $5 million of the $147 million that the National Institute of Health invests in malaria research (a pittance compared to the $3.5 billion it invests in “Rare Diseases”) goes toward new projects likely to provide short-term benefits.
Of course, we need basic science to provide the intervention tools of the future. But we also need more balance between long-shot, speculative research and “shovel ready” technologies. Common-sense solutions such as mosquito repellent, housing modification and source reduction currently receive very little support despite their practicality and sustainability. And there’s nothing wrong with combining one or more of these approaches with bed nets. Why does everything have to be a magic bullet?
Unfortunately, today’s U.S. arguments over federal spending and our fiscal future only make things worse. Now is not the best environment to argue for increased foreign aid to prevent malaria.
For now, I can only grit my teeth and continue to promote the kinds of measures that might ease the coming impact and preserve some of our hard-won gains.
Tony Kiszewski is associate professor of Natural and Applied Sciences at Bentley University.