Some of the world's most gruesome diseases are finally getting a bit of attention.

The worst-ever Ebola outbreak, which has already killed at least 2,296 people in West Africa, has triggered a scramble to develop the first drug or vaccine for a deadly disease that was discovered nearly 40 years ago in the forests of central Africa.

But Ebola is not the only tropical disease without a cure, and many other infections for which effective treatments are lacking or not widely available afflict far larger populations.