World Health Organization Director-General Margaret Chan outlined the challenges in the international fight against Ebola and called for immediate action on Friday. Chan told leaders of Guinea, Liberia, Sierra Leone and Cote d’Ivoire that she was making herself responsible for the response to the outbreak and offered her “frank” assessment, acknowledging that the Ebola outbreak is the largest in terms of deaths and geographic spread. She said this effort "must mark a turning point" in the battle against the deadly virus. 

According to Chan, over 60 of the 729 confirmed Ebola deaths have been health care workers, which greatly hinders local and international efforts to effectively answer the outbreak. Both Sierra Leone and Liberia lost their top doctors in charge of the Ebola response. Two American aid workers were also infected last week and are in "grave condition."

A significant portion of a $100 million joint WHO and locally led response boost announced yesterday will be used for bringing in experienced staff and for training local staff.

“The situation in West Africa is of international concern and must receive urgent priority for decisive action at national and international levels,” Chan said in the address. “Experiences in Africa over nearly four decades tell us clearly that, when well managed, an Ebola outbreak can be stopped.”

The Ebola virus currently is not a significant health risk to anyone not in immediate contact with a person with the virus, but she says local and international authorities cannot allow the virus the chance to mutate into one that is more contagious.

“Constant mutation and adaptation are the survival mechanisms of viruses and other microbes. We must not give this virus opportunities to deliver more surprises,” Chan said.

Seychelles health authorities barred Sierra Leone's national soccer team from flying to the island nation for fear of the virus spreading to their team. 

Chan announced that an Emergency Committee will be convened next week to discuss the outbreak in the international context. The outbreak has caused international concern after it made its way from Liberia to Nigeria via a Liberian-American man traveling on business. For a full transcript of her address, click here.