From Friendship to a Flourishing Collaboration

In 1996, Kearsley “Karrie” Stewart, Ph.D., was in Hoima, Uganda, studying social and cultural aspects of HIV among rural youth for her doctoral research. One day, a high school student knocked on her door, introduced himself as Joel Kibonwabake, and politely suggested she was overlooking an important population in Hoima: disabled youth. Intrigued, Stewart invited him in for tea, heard him out, realized he was right, and asked him to join her team as a research assistant. 

“That was the foundation of our 30-year collaboration,” said Stewart, who is a professor of the practice of global health and cultural anthropology at the Duke Global Health Institute.

The pair continued to work together on HIV-related projects after Stewart became a professor at Northwestern University and Kibonwabake became one of the few male nurses in Uganda. Over time, Uganda set up effective public health programs for HIV. But when Kibonwabake was assigned to a clinic in Kalangala District, a set of rural and remote islands in Lake Victoria, he saw an urgent need to address another condition: sickle cell disease.

“We had a family of twins with sickle cell disease,” he said, “and when they came to the clinic with sickle cell crisis, we had to refer them to the nearby district of Masaka, which takes 6 to 9 hours to reach.”

More Prevalent, More Lethal

In sickle cell disease, a person’s red blood cells are prone to folding into misshapen sickles, which can clump together and block arteries, causing severe pain and organ damage. Other complications include infections and anemia. Because the genes involved in the disease offer some protection against malaria, sickle cell is more prevalent in Africa. In Uganda, 20,000 children are born each year with the disease, 10 times more than in the U.S.

The disease is also significantly more dangerous in low-income countries, where diagnosis and treatment are scarce. Medicines that can reduce symptoms are typically not available in rural Africa, and new gene therapies that can halt disease progression aren’t offered anywhere on the continent. In Uganda, only one in five children born with sickle cell disease survives past age five.

After attending a workshop to learn more about the disease, Kibonwabake decided to launch the region’s only sickle cell clinic. His first patients were the twins. Ten years later, the clinic has more than 120 patients, and the twins, now teenagers, are doing well. 

Soon after opening the clinic, Kibonwabake reached out to Stewart for support. The invitation came at an opportune time: Stewart had joined the Duke faculty and was looking for field projects for her students. “Sickle cell disease is chronic and you need testing, lifelong medicines, and counseling,” Stewart said. “All this, Uganda has achieved with HIV, so why can’t we do that with sickle cell? I was convinced that this is the right moment to bring students in to really make a contribution.”

Since 2022, Stewart has taken several groups of students to Kalangala, including undergraduates, medical students and students in DGHI’s Master of Science in Global Health (MS-GH) program, as well as public health students from the University of North Carolina-Chapel Hill. Students have participated in educational outreach to far-flung Kalangala villages and rotated in the clinic. This summer, one of those students – Maddie Kitts, who completed her MS-GH in 2025, earned a Fulbright scholarship to continue her research on the barriers and opportunities related to universal newborn screening for sickle cell disease.

“Duke understood our problem and has helped a lot,” Kibonwabake said. “Through Duke, we are getting people coming in for research and training and also helping us to find grants.”

Treatment for All

One of the clinic’s first goals was to get all their patients on daily hydroxyurea. The drug, which needs to be taken for life, is not available in local pharmacies and, in any case, is too expensive for most people in Kalangala. So Stewart set about raising funds. “Our proudest moment – we call it our birthday – was November 22, 2022, which is the first day we offered free hydroxyurea to everyone in our clinic,” she said.

Kibonwabake said the medicine has reduced hospital admissions for patients, cutting down on missed days of school or work. It’s also reduced the stigma surrounding the disease. “The patients have developed confidence in the service we give them,” he said, “and they have started changing their attitudes toward the disease. They understand the disease now.”

Now, the team wants to gather the evidence to show daily hydroxyurea works, which could encourage Uganda and other sub-Saharan African countries to make it readily available. 

“If you want to change policy you have to make a case,” said Stephanie Ibemere, Ph.D., a DGHI affiliate and assistant professor in the Duke School of Nursing, who collaborates with Stewart in Uganda and also studies sickle cell disease in Nigeria. “We are going to build evidence that hydroxyurea is effective for individuals living in Uganda and we need to be sure that the efficacy in other African countries is the same.”

Julius Muchangi, who is working with Stewart and Ibermere on his MS-GH at DGHI, is hoping to provide some of those insights. He spent last summer in Kalangala, studying the prevalence of pain among sickle cell patients who have been prescribed hydroxyurea. He’s also analyzing cultural and social factors that might trigger such crises. His work, presented at the recent DGHI Showcase, could inform treatment plans not just in Kalangala, but other African communities as well.

“Beautiful Data”

With hydroxyurea, children can avoid some of the worst complications of sickle cell disease and survive into adulthood.  But the key is identifying cases and starting treatment as early as possible. For that reason, the team is working to expand newborn screening, with the goal of testing all newborns within the next few years. 

But discussions about sickle cell risks can begin even earlier. To develop sickle cell disease, a child must inherit alleles from both parents, who might carry a sickle cell allele while showing no signs of the disease. The team has been promoting genetic testing for people of reproductive age to learn their status and counseling to help them understand the chances of their children developing the disease. This past summer, Ibemere led training sessions in Kalangala and Uganda’s capital, Kampala, to educate healthcare providers and community leaders about sickle cell inheritance and strategize ways to talk about the disease with patients. 

A less visible, but equally important, part of the clinic’s work has been in recordkeeping. The clinic has digitized its patient records, making it the first sickle cell clinic in Uganda to convert completely to electronic data. 

Kibonwabake expects the database to be a resource for many researchers. “We are seen as having beautiful and organized data, which can be utilized in Kalangala or utilized globally,” he said. “It’s the best [sickle cell] data in Uganda.” 

Small Partnership, Big Ripples

Through his long collaboration with Stewart and Duke, Kibonwabake has seen his small clinic grow into a model for sickle cell treatment and research in Uganda. But he envisions more. 

“One of my big hopes is to have a [free-standing] sickle cell clinic,” he said, “and to create a very serious sickle cell research wing, not only for Kalangala but for sub-Saharan Africa.” He also wants a patient from Kalangala to be the first in Uganda to be cured of sickle cell disease with gene therapy. 

They are lofty visions. But both Stewart and Ibemere said the key to the partnership’s success over the past decade has been following Kibonwabake’s lead. 

“We all understand on a cellular level, down to our mitochondria, that there is nothing we are going to do for Africans without those persons being at the table,” Ibemere said. “You need to have on-the-ground people integrated as investigators. That’s the thing that Karrie has done that I love. The co-PI is a Ugandan practicing in Uganda, so there’s no way we’re going to miss what is actually needed.”

And if they did miss anything along the way, Stewart knows Kibonwabake would be at her door, just as he was 30 years ago, with a better idea.