Mapping the end of malaria

A few years ago, I pulled off a purposeful prank. While I was giving a TED Talk on malaria to a room full of influential people, I opened a canister and let loose a small swarm of mosquitoes. “There’s no reason that only poor people should have the experience,” I said. I let the audience squirm in their seats for about half a minute before I let on that the mosquitoes were not infected with malaria. My gimmick worked. A distant problem suddenly got very close to home.

Today, gimmicks are no longer necessary for convincing Americans of the danger of mosquito-borne diseases. The spread of Zika virus in south Florida, Puerto Rico, and other parts of the U.S. has given millions of Americans a direct understanding what it’s like to live with the fear of mosquitoes and the harm they can do, especially to pregnant women and children.

The world must focus serious attention and resources on ending the Zika epidemic. At the same time, we should keep in mind that the overwhelming toll of mosquito-related illness and death comes from malaria. Malaria is the key reason mosquitoes are the deadliest animal in the world.

Over the years, I have been in hospitals in several African countries when malaria is at its peak. I’ve seen beds out in the corridors and two children to a bed. There’s nothing more painful to see than a child experiencing cerebral malaria, when the parasite is attacking the brain and causing horrible seizures. As a parent, these memories will stay with me for life.

That’s why it gives me great joy to share a new report published todayin The New England Journal of Medicine. Rigorous new data show that the malaria death rate in sub-Saharan Africa has declined by a stunning 57% since 2000. With almost 500,000 children still dying of malaria every year, we obviously have a long way to go. But cutting the death rate by more than half is a miracle. It’s one of the greatest success stories in the history of global health.

We’ve known for some time that malaria deaths have been declining steeply. The significance of this new study, which was produced by the Institute for Health Metrics and Evaluation, is that we now have the strongest evidence ever of just how steep the decline has been.

This progress on malaria is no accident. It’s the result of an unprecedented increase in focus and commitment by rich and poor countries alike. The amount of money available to pay for bed nets, effective medications, and malaria research rose by 1,000 percent from 2000 to 2015, fueling massive new prevention and control efforts in countries hit hard by malaria.

In Tanzania, a country that has led the way with a major scale-up, the mortality rate fell more than 80 percent from 2000 to 2015. I remember visiting Tanzania years ago during the rainy season and seeing overflowing hospitals. When I went back years later, there were almost no children in the wards.

Tanzanian health authorities have launched major campaigns to distribute insecticide-treated bed nets and encourage people—especially children—to sleep under them every night. They’ve done widespread spraying of insecticides inside homes and in urban ponds, puddles, and marshes where mosquitoes breed. And they’ve used great medications that contain a drug called artemisinin, which earned its discoverer, Youyou Tu, the 2015 Nobel Prize in Medicine. If you take three days’ worth of these pills, you can get rid of the malaria parasites in your bloodstream, which helps you and also stops you from being the source of malaria spreading back to other people.

And now we have an awesome new tool in our arsenal: precision malaria maps. In the same New England Journal article I mentioned above, the authors report on cutting-edge mapping efforts that have given us an ability to see at a very high degree of granularity (5 km by 5 km) the burden of malaria in sub-Saharan Africa. That’s super valuable for short-term interventions, like helping a country determine where to deploy health staff. It’s just as valuable for long-term efforts to reduce the rate of transmission and shrink the malaria map.

When you zoom in with these high-definition maps, you can quickly home in on the hot spots where malaria is hitting hard and yet existing tools like bed nets are not being used widely enough. These maps show that in most countries it’s actually a very small percentage of the country where the disease burden is high and you need to focus your interventions.

And here’s more good news: After years of investment, we now have better diagnostics for detecting infections in people who show no physical symptoms (because people who are infected with malaria parasites but don’t show signs of illness are a big part of the chain of transmission). We have helped private-sector companies develop new, safe insecticides that will allow us to preserve the gains we have made against malaria. We have also helped bring to market simple technologies to protect families from mosquitoes, such as “eave tubes” that kill mosquitoes trying to enter homes and new traps which exploit mosquitoes’ attraction to sugar to kill them outdoors.

As a result of all this progress, I am confident that we can pursue the end goal of not just shrinking the malaria map but wiping malaria off the map altogether. Last year, Ray Chambers, the UN Secretary General’s special envoy for malaria, and I put forward a concrete plan for eradicating the disease by 2040. The potential upside is enormous: 11 million lives and $2 trillion dollars of economic impact. And the alternative to eradication—controlling the disease forever without eliminating it—is biologically and politically untenable. It would require endless investment in the development of new drugs and insecticides just to stay one step ahead of disease resistance. I also believe it would be impossible to maintain strong political commitment to fighting malaria unless we can define a clear end point. History has shown that unless countries rid themselves of malaria altogether, they eventually see the disease come roaring back on a massive scale.

To achieve eradication by 2040, we’ll need several other key innovations under development to come to fruition.

First, we’ll need new classes of drugs that completely clear malaria parasites from the body with just one dose. We should have these new cures in about a decade.

Second, we need new tools that can prevent malaria transmission. This can either be done with an effective malaria vaccine or by reducing mosquito populations. We will soon have a first-generation vaccine, but it protects a child for less than six months without a booster dose. I’m betting that within the next 10 years, researchers can produce a vaccine that provides much longer protection.

We have another potential game-changer in the works. Our foundation is supporting scientists who are using a powerful new tool called “genome editing” to introduce genetic changes in the Anopheles gambiae species of mosquito, one of the most effective transmitters of malaria in Africa. These genetic edits cause females to produce mostly male, sterile offspring. In theory, scientists could drive this trait throughout entire populations of mosquitoes in much of Africa, dramatically reducing malaria transmission in a very short time. While I’m excited about the potential of this technology, I know that changing the mosquito genome in a permanent way is something that should be done only with incredible caution and care. My hope is that it will be possible to deploy some version of this technique in a safe manner within 10-12 years.

In 1999, Melinda and I made our first major investment in malaria—a grant to establish the Malaria Vaccine Initiative. Funding for malaria research was so diminished at the time that we nearly doubled the resources with that one single grant. That blew my mind.

Today, this is no longer a lonely fight. More than 50 countries have joined together to mobilize billions of dollars through The Global Fund. And these resources are coming not just from wealthy countries. African countries such as Benin, Côte d’Ivoire, Kenya, Namibia, Nigeria, Senegal, South Africa, Togo, and Zimbabwe are contributing as well. In fact, African countries are now, for the first time ever, mobilizing more of their own resources for malaria than they’re receiving from donors.

So the next time you hear skeptics charging that foreign aid doesn’t work, point to malaria. Foreign assistance has not chased away local resources. On the contrary, it’s encouraged African nations to step up their own health efforts. And the results have been nothing short of remarkable.