Ebola airborne? WHO investigating how epidemiologist without direct contact with patients contracted the disease

A third top doctor has died from Ebola in Sierra Leone, a government official said Wednesday, as health workers tried to determine how a fourth scientist also contracted the disease before being evacuated to Europe. The announcements raised worries about Sierra Leone's fight against Ebola, which already has killed more than 1,400 people across West Africa. The World Health Organization said it was sending a team to investigate how the epidemiologist now undergoing treatment in Germany may have contracted the disease that kills more than half its victims. "The international surge of health workers is extremely important and if something happens, if health workers get infected and it scares off other international health workers from coming, we will be in dire straits," said Christy Feig, director of WHO communications. Dr. Sahr Rogers had been working at a hospital in the eastern town of Kenema when he contracted Ebola, said Sierra Leonean presidential adviser Ibrahim Ben Kargbo on Wednesday. Two other top doctors already have succumbed to Ebola since the outbreak emerged there earlier this year, including Dr. Sheik Humarr Khan, who also treated patients in Kenema.