The World Health Organization (WHO) has said the spread of Ebola in West Africa is an international health emergency.
WHO officials said a co-ordinated response was essential to stop and reverse the spread of the virus.
In Nigeria, one of the latest countries to be affected, President Goodluck Jonathan has declared a national state of emergency.
More than 960 people have died from Ebola in West Africa this year, two of them in Nigeria, the WHO says.
There were 68 new cases and 29 deaths reported over the course of two days this week, the United Nations health agency revealed on Friday.
It brings the total number of cases to 1,779.
There were 26 new cases in Sierra Leone and 38 in Liberia, but no new cases in Guinea, where the outbreak began.
The WHO said the outbreak was an “extraordinary event”.
“The possible consequences of further international spread are particularly serious in view of the virulence of the virus,” it said after the meeting.
WHO director-general Dr Margaret Chan appealed for help for the countries hit by the “most complex outbreak in the four decades of this disease”.
She said there would be no general ban on international travel or trade.
Guinean Ebola survivor
A fifth year medical student in Guinea tells the BBC French Service about how she is being shunned since recovering from Ebola which she caught whilst working as an intern at a clinic in March:
We are stigmatised – you know when they look at us like that, even in my own family people are rejecting me. I live with my uncle – my parents are in the village. In the house I eat alone. I feel lonely.
When I felt better, I started going back to medical school. Many distanced themselves from me. Four of us used to sit together, but I ended up sitting by myself.
The treatment centre gave me a certificate showing I had been healed. I showed it to my teachers as I’d missed some assessments while sick. But I haven’t done the two exams. The head of department told me to stay at home and get treated. I can’t even get an internship.
Keiji Fukuda, the WHO’s head of health security, said that with the right steps and measures to deal with infected people, Ebola’s spread could be stopped.
“This is not a mysterious disease. This is an infectious disease that can be contained,” he said. “It is not a virus that is spread through the air.”
Prof David Heymann of the London School of Hygiene & Tropical Medicine, said the recommendations were “comprehensive and evidence-based”.
Prof Tom Solomon, of the UK’s NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, welcomed the emphasis on outbreak control in local areas, including the use of full personal protective equipment (gowns, masks, gloves and goggles) with proper training.