Geneva, October 31 (RHC)-- The World Health Organization says the number of reported Ebola cases has jumped to more than 13,700 — a rise of more than 30 percent over a four-day period. The rise has been attributed to underreporting.

The World Health Organization also says Liberia, the country worst hit by the epidemic, may be seeing a decline in Ebola. Assistant Director-General Bruce Aylward said he is cautiously optimistic, saying that the Liberian government "is really driving a multi-pronged investigation looking at multiple strands of evidence to try and understand is this real, is this a reporting phenomena, or is it even a care-seeking phenomena that's changing."