Top Ebola experts raised grave concerns today about the worsening epidemic in west Africa as the number of infections soared to almost 10,000 and the death toll edged closer to 4,900.
The World Heath Organization said after an emergency meeting on the deadly haemorrhagic fever that the situation in the worst-hit countries of Guinea, Liberia and Sierra Leone "remains of great concern" as cases increase exponentially.
A total of 976 cases have come in the last seven days alone, said Isabelle Nuttall, head of the UN agency's alert division.
WHO said the outbreak remains "a public health emergency of international concern".
It formally declared a global emergency in August, sparking outside criticism and internal soul-searching over claims that it was too slow, as the first case was in Guinea in December.
WHO's deputy chief, Keiji Fukuda, said the international community had for months been ramping up the fight, with 600 international experts deployed in the embattled region over recent weeks.
Its "70/70" plan aims by December to ensure 70 per cent of people infected by Ebola are placed in medical isolation, and, given that dead bodies can spread the virus, to ensure 70 per cent of burials are conducted safely.
"By the beginning of December, we hope to see a bend in the curve. It's clear that it remains quite a challenge right now," Fukuda said.
He pointed to major efforts to "break the chain of transmission" by setting up special Ebola wards to try to save the lives of those struck by the virus and stem fresh infections.
"But it has been terrifically difficult to get enough health workers -- both domestic health workers as well as international health workers -- and this continues to be one of the major challenges," he said.
Health workers have paid a heavy price, with 244 deaths out of 443 cases across the affected countries.
The hunt is on for a vaccine, with supplies of Canadian-discovered experimental vaccine rVSV arriving in Geneva for a new round of trials.
Hopes are also centred on ChAd3, an experimental vaccine made by British company GlaxoSmithKline.
Whichever proves its mettle in trials, WHO hopes to deploy tens of thousands of doses to Africa by early 2015 for "real-world" tests.
WHO held closed-door talks Thursday on the issue of access to and financing vaccines, as officials said costs could be in the "hundreds of millions" of dollars.
