WHO said there were 85 new cases between July 8 and 12, highlighting continued high levels of transmission.
International and local medics were struggling to get access to communities as many residents feared outsiders were spreading rather than fighting Ebola.
“It’s very difficult for us to get into communities where there is hostility to outsiders,” WHO spokes- man Dan Epstein told a news briefing in Geneva.
“We still face rumours, and suspicion and hostility... People are isolated, they’re afraid, they’re scared.”
Sierra Leone recorded the highest number of deaths, which include confirmed, probable, and suspect cases of Ebola, at 52. Liberia reported 13 and Guinea 3, according to the WHO figures.
Epstein said the main focus in the three countries is tracing people who have been exposed to people with Ebola and monitoring them for the 21 day incubation period to see if they were infected.
“It’s probably going to be several months before we are able to get a grip on this epidemic,” Epstein added.
The outbreak started in Guinea’s remote southeast but has spread across the region’s porous borders despite aid workers scrambling to help some of the world’s weakest health systems tackle a deadly, infectious disease.
In Sierra Leone and Guinea, experts believe scores of patients are being hidden as relatives and friends believe hospitalisation is a “death sentence”. In Liberia, health workers have been chased away by armed gangs.
Ebola is a form of haemorrhagic fever which is deadly in up to 90% of cases.
It can fell victims within days, causing severe fever and muscle pain, vomiting and diarrhoea — and in some cases, organ failure and unstoppable bleeding.
Ebola is believed to be carried by animals hunted for meat, notably bats.
It spreads among humans via bodily fluids including sweat, meaning you can get sick from simply touching an infected person. With no vaccine, patients believed to have caught the virus must be isolated to prevent further contagion.
“Our tactic is to get insiders, including religious leaders, community leaders, people respected, who can go into the communities,” said Epstein.
He said that was also a key means of quashing rumours about the disease, which continue to circulate.
Ebola first emerged in 1976 in what is now the Democratic Republic of Congo, and is named after a river in that country.