Apr 21, 2022 7:00 AM

Drones Have Transformed Blood Delivery in Rwanda

The autonomous aircraft have shuttled blood to rural, mountainous areas for years. A new analysis proves they’re faster than driving.

zipline drone dropping a package with a parachute attached

Six years ago, Rwanda had a blood delivery problem. More than 12 million people live in the small East African country, and like those in other nations, sometimes they get into car accidents. New mothers hemorrhage. Anemic children need urgent transfusions. You can’t predict these emergencies. They just happen. And when they do, the red stuff stored in Place A has to find its way to a patient in Place B—fast.

That’s not a huge problem if you live in a city. In the United States and the United Kingdom, 80 percent of the population clusters around urban hubs with high-traffic hospitals and blood banks. In African nations like Libya, Djibouti, and Gabon, about 80 to 90 percent of the populations live in cities, too. But in Rwanda, that number flips: 83 percent of Rwandans live in rural areas. So, traditionally, when remote hospitals needed blood, it came by road.

That’s not ideal. The country is mountainous. Roads can be hot, long, and bumpy. If kept cool, donated blood can be stored for just a month or so, but some components that hospitals isolate for transfusions—like platelets—will spoil in days. A turbulent drive is not a perfect match for such finicky cargo.

That logistics issue historically incentivized rural facilities to order more blood than they needed. “There was a problem of overstocking,” says Marie Paul Nisingizwe, a PhD candidate in Population and Public Health at the University of British Columbia, who focuses her research on Rwanda, her home country. Stocking a little extra could save time later. But if a low-traffic facility didn’t wind up using the blood before it expired, they'd have to dump it.

In 2016, Rwanda’s government signed a contract with Zipline, a San Francisco-based drone startup, to streamline blood deliveries. Zipline’s autonomous drones would fly the blood from a distribution hub to the health care facility. The blood, contained within an IV bag, would parachute down in an insulated cardboard box, and the drone would zip back. Today, Zipline has two hubs in Rwanda; each can make up to 500 deliveries per day.

And now for the first time, there’s proof that drone blood services improve delivery speed and reduce waste. Writing in the April issue of Lancet Global Health, Nisingizwe analyzed nearly 13,000 drone orders between 2017 and 2019 and found that half of the orders took 41 minutes or less to deliver by drone. On the road, that median time would be at least two hours. Reports of wasted blood donations dropped.

The study is the first to analyze medical delivery drones in Africa. (Drone programs are more common in higher-income countries, where they are used to deliver medicine and defibrillators.) “It's amazing to see that actually the delivery drone is feasible in African settings,” says Nisingizwe. (Her research team is not affiliated with Zipline.)

“It’s so good. And it’s not just good for Rwanda,” says Timothy Amukele, a pathologist who is not involved with the research team or Zipline, but who previously ran a medical drone group with projects in Namibia and Uganda. (Amukele is currently the global medical director for ICON Laboratory Services, which helps run clinical trials.) Drone applications for global medicine have been touted for years, but researchers have lacked concrete data to back up that promise, says Amukule: “This is more than just guys playing with toys.”

“Drones are not easy,” he continues. “To actually make this a success, where they're getting blood and packing it safely and releasing the drones and monitoring the flight and bringing them back—and for five years covering 80 percent of that country—it’s just really impressive.”

Courtesy of Zipline International

Don’t be fooled by Rwanda’s rural demographics; the country has a reputation for leaning into health tech innovations. Rwanda’s universal health care system reaches over 90 percent of the population. In 2009, the government piloted a phone-based program, called RapidSMS, to track and reduce maternal and child mortality. By 2013, RapidSMS connected 15,000 villages to the country’s wider network of doctors, hospitals, and ambulances.

“They have one of the most complete electronic data systems,” says Michael Law, Nisingizwe’s advisor and a health policy researcher at UBC, which lets Rwanda’s Ministry of Health track how many people see physicians, how many have malaria or HIV, and how many give birth at health facilities. That’s a gold mine for researchers like Nisingizwe, who want to measure just how much innovation helps. “Frankly, we couldn't have done this evaluation had they not had the data system in place,” says Law.

Before starting her analysis, Nisingizwe traveled to Rwanda to learn about the traditional logistics for delivering blood there. When rural hospital workers needed blood, they’d fill out paper forms, which a driver would take to a national transfusion facility. Staff would fill the order, and the driver would return with it.

Zipline’s drone system seemed more efficient. (The major X-factor for drones is weather—Rwanda is very mountainous, so flying conditions can turn dicey fast—which is why flight operators check the weather and confirm the best route for every approved delivery.) But Nisingizwe wanted to measure how much drones reduced travel times and waste, if at all. She began pulling data from Zipline and Rwanda’s health information system for her analysis, such as order volumes, delivery times, and locations.

Almost immediately, her data revealed that drones beat cars. Delivery times vary by distance, but drones consistently outpaced typical driving times. In 12,733 orders over 32 months, the smallest difference was a three-minute boost and the largest was 211 minutes, always in favor of drones.

The drones also reduced the quantity of blood that expired and went to waste. “I wasn't expecting to see an impact right away,” Nisingizwe says. “But we immediately saw the effect.” Those savings increased with time: 12 months in, drones reduced wasted blood by 67 percent—totaling 140 fewer expirations for the 2017 to 2019 period.

“It's exciting for us,” says Israel Bimpe, a trained pharmacist and the director of Zipline’s Africa Go-To-Market division, based in Rwanda. “It's a validation of the work that we've been doing, in many ways.” In the years since starting blood distribution in Rwanda, Zipline has also partnered with the government of Ghana, in West Africa, to deliver blood, medicine, and vaccines by drone.

The drones seem to answer a huge need, says Kathryn Maitland, a pediatrician from Imperial College London, who was not involved in the study. Maitland has lived in East Africa for 22 years, and she works on clinical trials for critical illnesses. To her, drones are particularly useful for emergency blood transfusions. Children in East Africa face the threat of malaria, which can cause severe anemia. “They’re often very sick,” she says. “If you need a transfusion, you need it now.” Yet traveling for a transfusion takes time that could jeopardize a sick kid’s life. And it’s expensive. “These things could be a game changer,” Maitland says of drone delivery. “Certainly for places that are hard to get to.”

Thanks to drone delivery, rural facilities can now order rarer blood products, including platelets, fresh frozen plasma, and cryoprecipitates—special proteins isolated from plasma. If these were out of stock locally, patients would previously have been referred to another hospital and transported via ambulance.

“The performance has been better than could be expected,” says Jonathan Ledgard, an author and futurist who has helped advance the vision of medical drones in Africa. (Ledgard serves on advisory boards for businesses in the drone industry.)

But the cost of these deliveries is an open question. In an emailed statement, Zipline’s senior VP of external affairs, Anne Hilby, confirmed that the company and the government of Rwanda have not disclosed cost details, adding that that price can vary based on a customer’s needs. “Zipline provides a faster, more sustainable delivery method while remaining cost-competitive with traditional delivery and courier services,” she wrote.

Ledgard would like to see more transparency about that contract between Rwanda and Zipline. “I think it's important that the taxpayers in those countries get to see how much it really costs, and what they are getting out of it,” he says.

Nisingizwe did not analyze how much more Rwanda pays to tote blood with drones instead of cars, but she’d like to study that next. She also wonders whether the drones actually saved lives—something she’d like to investigate later by analyzing whether emergency referrals to urban hospitals have fallen, or if there have been drops in severe outcomes like hemorrhages.

As drone companies try to expand into other nations, they must also assuage the political concerns of some state officials, who fear that drones could be used to drop bombs. “Any airframe which is big enough to carry something valuable for communities is, by default, big enough to carry something which could damage those communities,” says Ledgard.

Other challenges are technical. Ledgard says that drones’ biggest current limitation is battery size. Until batteries get cheaper and more powerful, they’ll restrict payload and range. And Amukele notes that drone deliveries are inherently one-way operations: They can drop blood off by parachute, but they can’t pick up samples. That's the tradeoff of using drones shaped like planes instead of quadcopters, he says. Quadcopters can't carry payloads as effectively, but they're easier to land and take off.

But to Zipline’s Bimpe, so much has changed since 2016, when the company made its first drone delivery in Rwanda. “The first hospital that we started with—they probably have new doctors, new nurses,” says Bimpe. “And those people have no idea how to receive blood other than using drones.”