Some blame witchcraft. Others think it's a bad batch of moonshine.
But Esther Okaya, who lives in Korogocho, a slum in Nairobi, Kenya, says even teetotalers are falling victim. One minute quarreling with a neighbor; the next minute, dead.
And it's happened to her.
Okaya's husband left her. He took the money for her children's school fees. A few mornings later, her 9-year-old son shuffled home after being turned away by the teacher.
And then she felt it. It was as if her heart seized up. She could not breathe.