The international response to Ebola is still too slow and piecemeal, Doctors Without Borders warned Tuesday, as officials said the disease is crippling the economies of the three West African countries hardest hit. Ebola has infected nearly 17,000 people, of which about 6,000 have died, according to the World Health Organization. The vast majority of infections are in Guinea, Liberia and Sierra Leone, poor countries that have been left to handle...