The top doctor treating patients infected with the Ebola virus (external - login to view)
in Sierra Leone has died from the disease, officials have confirmed.
Dr Khan's death on Tuesday afternoon was confirmed by chief medical officer Dr Brima Kargbo, who had previously hailed him as a "national hero" when she announced he had contracted the the disease.
Efforts are further hindered by the fact the disease has no vaccine and no specific treatment. The current outbreak has a fatality rate of at least 60 percent, but it can reach as high as 90 percent.
Ebola virus: Top Sierra Leone doctor, Sheik Umar Khan, dies of disease - Africa - World - The Independent (external - login to view)
Nigeria death shows Ebola can spread by air travel
Nigerian health authorities raced to stop the spread of Ebola on Saturday after a man sick with one of the world's deadliest diseases brought it by plane to Lagos, Africa's largest city with 21 million people.
The fact that the traveler from Liberia could board an international flight also raised new fears that other passengers could take the disease beyond Africa due to weak inspection of passengers and the fact Ebola's symptoms are similar to other diseases.
Officials in the country of Togo, where the sick man's flight had a stopover, also went on high alert after learning that Ebola could possibly have spread to a fifth country.
Screening people as they enter the country may help slow the spread of the disease, but it is no guarantee Ebola won't travel by airplane, according to Dr. Lance Plyler, who heads Ebola medical efforts in Liberia for aid organization Samaritan's Purse.
"Unfortunately the initial signs of Ebola imitate other diseases, like malaria or typhoid," he said.
Nigeria death shows Ebola can spread by air travel (external - login to view)