The WHO chief also underlined that the coordination among global health partners was essential, too, before highlighting that even he had problems in accessing rural Bikoro to see the problem first-hand, during his visit to the area shortly after the beginning of the outbreak.
The spread of the often lethal hemorrhagic fever to a provincial capital of 1.2 million people has health officials scrambling to monitor for Ebola at busy ports in the capital, Kinshasa, which is downstream from the infected city of Mbandaka on the Congo River. He said officials were trying to monitor about 900 contacts of Ebola cases but couldn't say how numerous newly reported cases are coming from previously identified contacts.
Nine new suspected cases of Ebola were reported in the northwestern Democratic Republic of Congo as authorities tackling the outbreak face challenges including resistance by local communities and multiple chains of transmission.
"With 58 confirmed, probable or suspected cases of the disease in the country as of Wednesday, effective tracing of anyone who had come into contact with the disease would "make or break" the response to Ebola", Salama said.
"The victim will be far from others so that he can not contaminate them".More news: Serena Williams back in the Grand Slam groove in Paris
The WHO emergencies chief, Dr. Peter Salama, warned Wednesday that "the next few weeks will really tell if this outbreak is going to expand to urban areas or if we're going to be able to keep it under control".
Three patients infected with the deadly Ebola virus escaped from a hospital holding them in a quarantine station in Mbandaka, Congo. As of this week, the World Health Organization said 628 such contacts had been listed in Congo.
"This is a work in progress", Salama said, adding that the "overwhelming majority" of contacts were being followed up on a daily basis and that vaccination was providing further reassurance the epidemic might soon be controlled.
Ebola is initially transmitted to people from wild animals, including bats and monkeys.
The WHO official confirmed that a selective, or "ring vaccination" programme had just begun and that efforts were ongoing to ensure that the Ebola drug could be stored in "ultracold" conditions at between -60 and -80°C.More news: Celtics' Ainge: Prepared to stand pat this summer (maybe)
There is no specific treatment for Ebola.
World Health Organization began vaccinations this week and is using a "ring vaccination" approach, targeting the contacts of people infected or suspected of infection and then the contacts of those people.
The idea is to quickly immunize those at highest risk of contracting the virus before they could potentially become infected and spread it themselves. Symptoms include fever, vomiting, diarrhea, muscle pain and at times internal and external bleeding.
Having new cases arise from people not already under observation suggests the virus could be spreading unchecked in certain areas.More news: White House to hit China with tech tariffs ahead of trade meeting