United Nations

ASSOCIATED PRESS -By MARIA CHENG and SARAH DiLORENZO Dec. 14, 2014

LONDON--As health officials struggle to contain the world's biggest-ever Ebola outbreak, their efforts are being complicated by another problem: bad data.

Having accurate numbers about an outbreak is essential not only to provide a realistic picture of the epidemic, but to determine effective control strategies. Dr. Bruce Aylward, who is leading the World Health Organization's Ebola response, said it's crucial to track every single Ebola patient in West Africa to stop the outbreak and that serious gaps remain in their data.

"As we move into the stage of hunting down the virus instead of just slowing the exponential growth, having good data is going to be at the heart of this," Aylward said. "We are not there yet and this is something we definitely need to fix."