The Ebola virus epidemic in Guinea, Sierra Leone and Liberia is "out of control," the medical charity Doctors without Borders said Monday as the World Health Organization works to enhance its response.

There have been 350 deaths since the epidemic began in Guinea’s capital, Conakry, according to the WHO. The outbreak began in early December 2013 in Guinea, the European Centres for Disease Control and Prevention says. It is the deadliest outbreak since Ebola first emerged in 1976.

"The epidemic is out of control," said Bart Janssens, director of operations with Doctors without Borders. "With the appearance of new sites in Guinea, Sierra Leone and Liberia, there is a real risk of it spreading to other areas."

In terms of number of cases and deaths, this is the biggest outbreak of Ebola, said Marc Poncine, emergency co-ordinator for Doctors without Borders in Conakry. Poncine has also been at the centre of the epidemic in a rainforest region on the border of Sierra Leone and Liberia.

The epidemic is also unprecedented in its geographical distribution, the aid agency said.

Poncine said several factors are complicating efforts to control the current outbreak:

Part of the population doesn’t believe that Ebola exists as a contagious illness caused by a virus, so patients aren’t coming to treatment centres.

People have more confidence in traditional practitioners than the health system, which means health officials have trouble stopping the spread of the virus.

The highest risk of infection occurs when a person dies. At funerals, people prepare the corpse and mourners also touch the body, which increases the risk of contamination.

"We are very stretched, that’s for sure," said Poncine. "Patients can be cured."

Dr. Tim Jagatic of Windsor, Ont., is a general practitioner and volunteer with Doctors without Borders who was in Conakry from the end of March to mid-April, when he helped to treat the first small wave of patients.

"We were seeing good outcomes with these patients; there is a 90 per cent mortality attached with the Ebola virus, the Zaire strain, and in my personal experience we were seeing about a 50 per cent mortality rate," Jagatic said.

Countering fear and misconceptions

One of the misconceptions about Ebola surrounds the hemorrhagic part of the disease.

"One of the points of fear for many people is that they automatically assume that there is a violent hemorrhagic outburst associated with this disease," but less than half of infected patients develop those signs, Jagatic said.

The work itself is physically taxing, given the physiological stress of wearing hazard suits in 35 to 40 C heat, he recalled.

"At one point we did have a staff nurse who tested positive for Ebola. It was difficult seeing a colleague go through the emotional stress of being infected and not knowing what his outcome would be." The nurse has recovered.

In Sierra Leone, many people are worried, said Amara Bangura, a journalist in Freetown who works for BBC Media Action. He’s been broadcasting health alerts on the radio to try to get the word out about the warning signs, travel restrictions and health precautions.

"In most traditional areas, people do not strongly believe that the virus does exist. What they believe is that this whole sickness is caused by evil spirits," Bangura said.

"It complicates things for the Ministry of Health and other health workers particularly, because people are refusing to go to the medical test centres that have been spotted in the Kailahun district."

Canada’s government has responded to the World Health Organization’s request for assistance. The Public Health Agency of Canada has deployed a team of scientists and a mobile lab to Guinea to contribute to efforts to control and stop the Ebola outbreak, a spokeswoman for the agency said.

In an update, the WHO said it is working with the West African governments to provide technical expertise.

The WHO plans a two-day regional meeting in Accra, Ghana, for July 2.