In Rwanda, a country with not a single cancer specialist, 5-year-old Umulisa Husna Rutagengwa was lost. For months, she bounced among hospitals, as doctors searched for the cause of her fatigue, fever, and pain. Finally, they had an answer: leukemia.

More than 80 percent of children with her type of leukemia survive in the United States. In Rwanda, the disease is almost always fatal.