Reported death toll. The biggest cause for concern is that every story that comes out immediately starts talking about how we don't really know how many people are infected or have died, due to the distrust of the local population in medicine.

The second paragraph in this story states that recorded cases of infection are now over 4000. With a 90% mortality rate, the known death toll will double in the next few weeks.

I don't think this is likely to become pandemic, but it must be a very scary situation in Africa.