Scott Dowell, with the Centers for Disease Control and Prevention in Atlanta, is leading its investigation into nodding syndrome. Usually, he says, investigators can figure out the cause of a strange outbreak after just a few weeks. This hasn't been the case here.
"Nodding syndrome is definitely unusual in that it's a much tougher nut to crack," he says.
For more than three years, epidemiologists at the CDC have been trying to crack it. They've gone to northern Uganda and collected blood samples, tissue samples, spinal fluid. Dowell says they've looked at all the infectious causes that CDC can test for, but the explanation is still not clear.
As a consequence, says Paul Bukuluki, a researcher in Uganda, people are trying to find their own answers. Bukuluki isn't interested in the cause of nodding syndrome, but rather, in how people can cope with the illness — and the unknown.
So, for the past year, Bukuluki and a small team of researchers have been traveling to the affected region of Kitgum, asking parents what they think the cause is. And he heard the same thing repeatedly: the Lord's Resistance Army's brutal, two-decade-long guerrilla war in northern Uganda.
During the conflict, tens of thousands of children were kidnapped; people were forced into sex slavery; massacres were commonplace.
People fled their homes in droves. A decade ago, nearly 2 million people — about 95 percent of those living in the region known as Acholiland — moved into internally displaced person camps
And there, in the camps, children suffered from nodding syndrome — sometimes two, three or four children in the same family.
Santa Olok, who lives in Aber's village, also has a daughter with nodding syndrome. She is a member of the region's predominant Acholi ethnic group. For her, the cause of the disease lies in a tribal belief in ancestor spirits.
"The spirits of the people who died here [during the war]," she says, "who are returning to hurt or haunt the people."
Bukuluki says he heard this answer, too. And it matters to him because this sort of reasoning goes beyond just figuring out the cause of nodding syndrome. It tries to answer an entirely different question: Why us?
Because Tumangu, with nearly 100 children diagnosed with nodding syndrome, has suffered decades of chaos and loss.
"One generation lost due to ... the two-decade war," Bukuluki says, "and another generation now being lost to nodding syndrome."