About 960 people have died from the disease. The outbreak is the largest and longest ever recorded of Ebola.
"Countries affected to date simply do not have the capacity to manage an outbreak of this size and complexity on their own," said Dr. Margaret Chan, WHO chief. "I urge the international community to provide this support on the most urgent basis possible."
The outbreak started in Guinea in March and spread to Sierra Leone and Liberia and then to Nigeria. According to reports, the disease spread when a man sick with Ebola boarded a plane to Nigeria. He later died and the nurse who treated him has also died from Ebola. Officials are monitoring seven other people who had first contact with him.
The disease has a 50 percent survival rate. There is no drug or treatment for Ebola.
However, two American who were infected with Ebola are being treated with a new drug, and they seem to be improving. WHO will meet again next week to discuss the use of experimental drugs during the outbreak.
"Statements won't save lives," said Dr. Bart Janssens, director of operations for Doctors Without Borders. "For weeks, (we) have been repeating that a massive medical, epidemiological and public health response is desperately needed. ... Lives are being lost because the response is too slow."
The U.S. Centers for Disease Control and Prevention has advised against traveling to West Africa, and WHO has recommended that those who have been around Ebola patients should not travel internationally.
Publication date: August 8, 2014